Module & More Bio Tg 4

  Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan TP 3

3. Aliran darah dikekalkan dalam dua cara: Pengecutan otot rangka
Contraction of skeletal muscles
The flow of blood is maintained in two ways:

Pengepaman jantung
The pumping action of the heart

Injap menghalang Pengecutan otot rangka
membenarkan darah
darah mengalir mengalir ke arah jantung
balik ke kaki
Valves prevent Blood flow up caused
backflow of by skeletal muscle contraction
blood to leg
Injap

buka
Valve
open

Otot rangka Injap
mengendur tutup
Skeletal muscle Valve
closed
relaxed
Otot rangka
mengecut
Skeletal muscle
contracted

(a) Jantung menghasilkan tekanan yang cukup tinggi (b) Semasa pergerakan, pengecutan otot menyebabkan pengecutan
supaya darah dapat mengalir dari arteri ke dan pengenduran vena.
kapilari .
The contractions of muscles during movement cause constriction and
The heart generates pressures great enough to drive relaxation of the veins.
blood through the arteries into the capillaries .
(c) Injap dalam vena memastikan bahawa pengaliran darah ke
jantung .

The valves in the veins ensure the blood flow towards the heart .

BAB 10 10.4 Mekanisme Pembekuan Darah

The Mechanism of Blood Clotting

1. Keperluan mekanisme pembekuan darah: TP 3

The necessity for blood clotting mechanism:

(a) Mencegah kehilangan darah yang berlebihan dari badan apabila terdapat kecederaan saluran darah.
Prevent excessive blood loss from the body when there is a damage of the blood vessel.

(b) Menghalang kemasukan patogen ke dalam badan dan jangkitan .
Prevent the entry of pathogens into the body and infections .

(c) Mengekalkan tekanan darah.
Maintain the blood pressure .

(d) Mengekalkan peredaran darah dalam sistem peredaran tertutup. Mekanisme
Maintain circulation of blood in the closed circulatory system Pembekuan Darah
Mechanism of Blood
VIDEO 8 Clotting

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2. Mekanisme pembekuan darah: Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan  

The mechanism of blood clotting: TP 2

1 Dinding salur darah tercedera mendedahkan 2 Platlet bergabung dengan

gentian kolagen . kolagen .
Damage to blood vessel wall exposes Platelets bind to collagen .
Membebaskan faktor
collagen fibres.
Membebaskan faktor pembekuan . pembekuan .
Releases clotting factors .
Releases clotting factors .
Plug platlet sementara terbentuk
3 Trombokinase aktif dalam darah (faktor X) Temporary platelet plug formed

Active thrombokinase in blood (factor X) Darah beku/
keruping
Ion kalsium Vitamin K
Calcium ions Blood clot /
5 Protein plasma aktif: Scab
4 Protein plasma tidak aktif:
Trombin
Prothrombin Active plasma protein:

Inactive plasma protein: Thrombin
Prothrombin

Protein terlarut: Protein tidak larut: Jaringan Memerangkap sel darah merah
Fibrinogen Fibrin Mesh Trapping red blood cells

Soluble protein: Insoluble protein
Fibrinogen Fibrin

3. Isu kesihatan berkaitan dengan pembekuan darah: TP 3 BAB 10

Health risk for excessive blood clotting: Hemofilia / Haemophilia

Trombosis dan Embolisme / Thrombosis and Embolism 1. Sejenis penyakit pewarisan di
mana darah tidak membeku secara
1. Trombosis adalah pembentukan darah beku di dalam salur darah yang tidak normal.
terluka.
A hereditary disease which the blood
Thrombosis is the clot formation inside an unbroken blood vessel. cannot clot normally.

2. Darah beku dikenali sebagai trombus . 2. Ini disebabkan oleh kekurangan
The blood clot is called thrombus . faktor pembeku dalam darah.

3. Trombus yang tertanggal dan bergerak mengalir mengikut aliran darah disebut This is due to the lack of production of
embolus . certain clotting factors in the blood.

A thrombus which dislodged and moves in the bloodstream is called embolus . 3. Pesakit berkemungkinan mati
disebabkan pendarahan yang
4. Embolus tersebut itu boleh tersangkut dalam arteri dan menyekat pengaliran berlebihan akibat luka dan lebam.
darah. Keadaan ini dikenali sebagai embolisme .
The affected person may die as a result of
The embolus may get trapped in arteries where it blocks the blood flow. The condition is excessive bleeding from minor cuts
called embolism . and bruises.

5. Sekiranya pembekuan darah berlaku di arteri koronari , tisu otot kardium di 4. Pesakit juga akan mengalami
bawah sekatan itu mungkin musnah disebabkan kekurangan bekalan oksigen , pendarahan dalaman.
ini akan membawa kepada serangan jantung . (penginfarkan miokardium).
He may also experience spontaneous
If a clot forms in a coronary artery, the cardiac muscle tissues below the obstruction internal bleeding .
may get damaged because of an inadequate supply of oxygen , which leads to a
heart attack (myocardial infarction).

6. Jika darah beku menyekat aliran darah ke otak , akan mengakibatkan strok .
If a blood clot blocks blood flow to the brain , it can result in stroke .

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  Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan

10.5 Kumpulan Darah Manusia

Human Blood Groups

1. Jenis darah seseorang ditentukan oleh kehadiran antigen tertentu di permukaan sel darah merah .
A person’s blood type is determined by certain antigens found on the red blood cell surface.

2. Dua pengelasan yang terpenting ialah jenis darah ABO dan Rhesus .
The two most important classifications are the ABO and Rhesus blood types.

Kumpulan Darah ABO dengan Pendermaan Darah

ABO Blood Groups and Blood Donation

1. Kumpulan darah ABO ditentukan oleh kehadiran antigen A dan B . TP 3

ABO blood group is determined by the presence of antigens A and B .

2. Jenis darah A mempunyai antigen A , jenis darah B mempunyai antigen B , jenis darah AB mempunyai
kedua antigen A dan B , jenis darah O tidak mempunyai antigen.

Blood type A has only antigen A , blood type B has only antigen B , blood type AB has both antigen A and B , and

blood type O has neither.

3. Di dalam plasma terdapat antibodi kepada antigen, anti-A dan anti-B .

Within the plasma are antibodies to the antigens, the anti-A and anti-B .

4. Antibodi anti-A menggumpalkan sel darah merah berantigen A ; antibodi anti-B menggumpalkan sel darah
merah berantigen B . Aglutinasi (Penggumpalan) membawa kepada hemolisis sel darah merah.

Anti-A antibody agglutinates any red blood cells with antigen A ; anti-B antibody agglutinates any red blood cells with

antigen B . Agglutination causes Iysis of foreign red blood cells.

Kumpulan darah Antigen pada sel darah Antibodi dalam plasma darah Boleh menderma Boleh menerima darah
Blood group merah Antibodies in blood plasma darah daripada

BAB 10 Antigens on red blood cells Can donate blood to Can receive blood from

A Anti-B A , AB A,O
Antigen A / Antigen A Anti-B

B Anti-A B , AB B,O
Antigen B / Antigen B Anti-A

AB Tiada AB AB , A , B , O
Antigen A dan B Neither
Antigen A and B

O Kedua-dua Anti-A dan Anti-B A , B , AB , O O
Both anti-A and anti-B

Tiada antigen A atau B
Neither antigen A nor B

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Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan  

5. Kumpulan darah O dikenali sebagai penderma universal kerana boleh menderma darah kepada mana-
mana jenis darah lain.

Blood group O is sometimes called the universal donor because it can donate to any other blood type.

6. Kumpulan darah AB adalah penerima universal kerana boleh menerima darah dari mana-mana jenis
darah yang lain.

Blood group AB blood is the universal recipient because it can receive blood from any other blood type.

Faktor Rhesus dalam Kehamilan TP 2

Rhesus factor in pregnancies Rh-negatif
Rh-negative (Rh-)
1. Kumpulan darah Rh ditentukan oleh kehadiran antigen D .

Rh blood group is determined by the presence of antigen D .

2. Rh-positif

Rh-positive (Rh+)

Rh+ Rh+
Antigen Rh Antibodi Rh
Rh antigen Rh antibody

Individu yang mempunyai faktor Rhesus / antigen D Individu yang tidak mempunyai faktor Rhesus /
pada sel darah merahnya. antigen D pada sel darah merahnya.

Individuals that have the Rhesus factor / D antigen on the red Individuals that lack the Rhesus factor / D antigen on the red
blood cells. blood cells.

3. Semasa pemindahan darah menerima darah Rh-positif BAB 10

During blood transfusion

(a) Apabila individu Rh-negatif

When a Rh-negative person receives Rh-positive blood

(b) Individu itu akan menghasilkan antibodi anti-D terhadap antigen itu yang mengakibatkan pengagglutinan .

The person will produce anti-D antibodies which results in agglutination .

(c)Antibodi akan kekal dalam peredaran darahnya.
The antibodies continue circulating in the person’s bloodstream.

Rh +/+ Rh –/–

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  Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan TP 3

4. Semasa kehamilan

During pregnancy

Ibu: Kehamilan pertama: 3. Ini merangsang sistem 6. Selepas kelahiran Kehamilan kedua:
Rh-negatif First pregnancy: keimunan ibu untuk bayi pertama, ibu Second pregnancy:
Mother: Rh-negative 1. Ibu membawa fetus menghasilkan antibodi mempunyai antibodi 7. Antibodi anti-Rh
anti-Rh . anti-Rh terhadap
Bapa: Rh+ . antigen-Rh . akan meresap ke dalam
Rh-positif This will trigger the aliran darah fetus baharu
Father: Rh-positive The mother carries the After first birth, the dan menyebabkan
Rh+ foetus. mother’s immune system mother has anti-Rh pengagglutinan .
Fetus: to produce anti-Rh Anti-Rh antibodies will
Rh-positif 2. Sebahagian kecil sel antibodies against
darah merah Rh+ antibodies. Rh antigen . diffuse into the bloodstream
Foetus: Rh-positive merentasi plasenta
memasuki aliran darah 4. Antibodi akan of the new foetus and cause
ibu. meresap ke dalam agglutination .
darah fetus.
Some of the Rh+ red 8. Akibatnya sel darah
The antibodies merah fetus mengalami
blood cells leak across diffuse into the hemolisis .
the placenta and may Eritroblastosis fetalis
enter mother’s blood. foetus’s blood.
berlaku.
BAB 10 5. Aras antibodi yang
rendah tidak This causes an excessive
haemolysis of
mencukupi untuk
menyebabkan apa-apa foetus’s red blood cells.
kesan ke atas fetus. Erythroblastosis
Low level of
antibodies does not fetalis occurs.
cause much harmful
effects to the foetus. 9. Bayi mengalami
kerosakan otak atau
kematian .

The baby suffers from brain
damage or may die .

10.6 Isu Kesihatan Berkaitan Sistem Peredaran Manusia

Health Issues Relating to Human Circulatory System

Keperluan Sistem Peredaran yang Sihat TP 3

The Necessity for a Healthy Circulatory System

1. Sistem peredaran yang sihat membekalkan oksigen dan nutrien kepada semua sel badan dan membuang

bahan kumuh. oxygen and nutrients to cells around the body and takes away wastes.

A healthy circulatory system delivers

2. Mengekalkan sistem peredaran yang sihat akan mengurangkan risiko penyakit kardiovaskular .

Keeping a healthy circulatory system will decrease the risk of cardiovascular diseases.

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Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan  

Karbon monoksida bergabung dengan hemoglobin membentuk 1. Merokok / Smoking
karboksihemoglobin menyebabkan pengangkutan oksigen
(a) Karbon monoksida dalam asap (b) Nikotin dalam rokok.
tidak efektif. Nicotine in cigarette.
Carbon monoxide binds to haemoglobin to form carboxyhaemoglobin rokok.
leading to inefficiency of transporting oxygen . Carbon monoxide in cigarette smoke.

Angina Strok / Stroke Pencerutan salur darah.
Constriction of blood
Plak Tisu mati Teruk Penginfarkan miokardium vessels.
Plaque Dead tissue Severe Myocardial infarction
Hipertensi
Arteri yang sempit Pembekuan darah Thrombosis koronari Hypertension
Narrowed artery mungkin berlaku di arteri Coronary thrombosis
koronari yang sempit. Aterosklerosis
2. Diet tak seimbang Blood clot may occur in Plak menyekat dan Atherosclerosis
Imbalanced diet narrow coronary arteries. menyempitkan

(a) Pengambilan makanan tinggi Pemendakan plak (lemak lumen, pengaliran darah
lemak dan kolesterol . dan kolesterol) di dinding menjadi perlahan.
dalam arteri . Deposits of Plaque clogs and narrows
High intake of fats and plaque (fats and cholesterol) on the lumen, blood flow
the inner walls of arteries . decreases.
cholesterol .

(b) Pengambilan garam
berlebihan

Excess intake of salt .

Meningkatkan tekanan osmosis darah. Plak menjadi keras dengan Arteri menjadi kurang Arteriosklerosis BAB 10
Increases the blood osmotic pressure. pengenapan kalsium . kenyal . Arteriosclerosis
The plaque becomes hardened
Less elasticity of artery.
with calcium deposit.

3. Kurang bersenam Obesity Hipertensi Jantung mengepam dengan
Lack of exercise Obesiti Hypertension lebih kuat. harder.
The heart has to pump
Gaya hidup yang banyak duduk .
Sedentary lifestyle.

Penyakit Kardiovaskular / Cardiovascular Diseases TP 3

Sebab: gaya hidup yang tidak sihat Cara mengatasi
Causes: unhealthy life style Way to overcome

(a) Diet tidak seimbang – diet yang tinggi lemak dan (a) Amalkan diet seimbang dan kurangkan pengambilan
kolesterol , tinggi garam dan rendah serabut . lemak tepu.

Imbalanced diet - a diet of high in fats and Maintains a balanced diet with a low intake of saturated fats .
cholesterol , salty food and low in fibre . (b) Mengurangkan makanan terlalu masin.
Reduce salty food.
(b) Kurang bersenam . (c) Selalu bersenam . / Exercise regularly.
Lack of exercise . (d) Elakkan berat badan yang kelebihan. / Avoid excess weight.
(e) Tidak merokok . / Do not smoke .
(c) Obesiti / obesity (f ) Kurangkan stres. / Reduce stress.

(d) Merokok / Smoking

(e) Stres / Stress

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  Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan TP 3

Rawatan Penyakit Koronari Jantung

Treatment of Coronary Heart Disease

Angioplasti / Angioplasty Belon Ubat / Medications
Kaedah membuang atau merawat Ballon Pelbagai jenis ubat untuk rawatan

pembentukan plak . Plak ASPIRIN RX boleh diguna
Methods of removing or treating plaque formations. Plug Various drugs can be used.

Pembedahan dilakukan dengan memasukkan Untuk mencegah pembentukan darah
belon kecil ke dalam salur darah. Belon beku di arteri.

kemudian mengembung dan membuang To prevent the formation of blood clots
plak tersumbat. in the arteries.
Surgery to insert a small balloon into a blood vessel
which is then inflated to remove a blockage. Pembedahan pintasan jantung / Bypass surgery
Meningkatkan aliran darah dalam salur Pakar bedah menggunakan salur darah di bahagian lain badan seperti betis
koronari.
Improves blood flow in coronary vessels. yang disambung untuk memintas arteri yang tersumbat bagi mengembalikan
proses peredaran darah.
The surgeon uses a blood vessel from another part of the body such as the leg to create a
graft that can bypass the blocked artery to restore blood flow.

10.7 Sistem Limfa Manusia

Human Lymphatic System

Pembentukan Bendalir Tisu dan Limfa / The Formation of Tissue Fluid and Lymph TP 2

BAB 10 Di hujung arteriol / At the arteriole end 3. Bendalir tisu akan membasahi sel-sel badan, Di hujung arteriol
membolehkan pertukaran bahan berlaku merentasi At the arteriole end
1. Tekanan hidrostatik darah di membran plasma secara resapan , resapan berbantu
kapilari adalah lebih tinggi dan pengangkutan aktif . 4. Tekanan darah di kapilari
berbanding bendalir di sekitar sel adalah lebih redah . Ini
badan. This tissue fluid constantly bathes the body cells, so exchange membolehkan sebahagian
of substances can occur across the plasma membranes by bendalir tisu masuk semula
Hydrostatic pressure of blood in the diffusion , facilitated diffusion and active transport. ke darah.
capillaries is higher than that of the Oksigen dan nutrien meresap masuk ke dalam sel;
fluid surrounding the body cells. Oxygen and nutrients diffuse into the cells; The blood pressure in the
Karbon dioksida dan bahan buangan lain meresap capillary is much lower .
2. Ini memaksa beberapa This allows some of the tissue
komponen plasma (contohnya keluar dari sel. fluid to re-enters the blood.
air , mineral, nutrien terlarut, Carbon dioxide and other wastes diffuse out from the cells.
lipid dan leukosit ) 5. Darah dalam kapilari masuk
meresap keluar melalui Sebahagian jaringan kapilari Sel 5 ke dalam vena .
dinding kapilari membentuk Part of capillary network Cells
bendalir tisu . 3 4 Blood from capillaries passes to
2 vein .
This forces some components of 1
the plasma (e.g. water , minerals, 7. Bendalir di dalam sistem
dissolved nutrients , lipids and 6 7 limfa adalah limfa dan
leucocytes ) to diffuse out of the Injap
capillary walls formed tissue fluid . Valves mempunyai komposisi yang
Protein plasma, eritrosit hampir sama dengan
dan platlet adalah terlalu Salur limfa bendalir tisu.
besar untuk meresap melalui Lymph vessei The fluid in the lymphatic
dinding kapilari dan kekal dalam system is called lymph and
darah. Nodus limfa is similar in composition to
Plasma proteins , erythrocytes Lymph node the tissue fluid.
and platelets are too large to pass
6. Sebahagian bendalir tisu yang berlebihan akan memasuki sistem limfa dan kembali ke
through the capillary walls. They sistem darah melalui vena subklavian.
remain in the blood.
Some excess tissue fluid is drains into the lymphatic system and returns it to the blood system in
the subclavian vein in the chest.

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Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan  

Perbandingan antara Kandungan Limfa, Bendalir Tisu dan Darah

Comparison between the Content of Lymph,Tissue Fluid and Blood

Persamaan / Similarities TP 4

1. Cecair berair. / Watery liquid.
2. Mengangkut gas , nutrien dan bahan buangan .

Transport gases , nutrients and waste products.

Perbezaan / Differences

(a) Limfa / Lymph (b) Bendalir tisu / Tissue fluid (c) Darah / Blood

Bendalir di dalam salur limfa . Bendalir di ruang antara sel dan tisu. Bendalir di dalam salur darah .
Fluid held in the lymphatic vessels . Fluid surrounding the cells and tissues. Fluid held in the blood vessels .
Terdeoksigen / Deoxygenated
Tidak mempunyai eritrosit dan platlet . Beroksigen / Oxygenated Beroksigen / Oxygenated
Does not contain erythrocytes and platelets .
Mempunyai limfosit . Tidak mempunyai eritrosit dan platlet . Mempunyai eritrosit , pelbagai leukosit
Has lymphocytes . Does not contain erythrocytes and platelets . dan platlet .
Mengandungi kurang protein. Mempunyai leukosit .
Contains few proteins. Has leucocytes . Has erythrocytes , various leucocytes and
Kandungan lipid tinggi . platelets .
High lipids content. Mengandungi kurang protein.
Contains few proteins. Mengandungi protein plasma .
Contains plasma proteins.
Kandungan lipid rendah .
Low lipids content. Kandungan lipid rendah .
Low lipids content.

Sistem Limfa / Lymphatic System

Sistem limfa terdiri daripada limfa , jaringan kapilari limfa, salur limfa, nodus limfa dan organ limfa.

The lymphatic system consists of lymph , a network of lymph capillaries , lymph vessels , lymph nodes and
lymph organs .

1. Limfa / Lymph 3. Saluri limfa / Lymph vessels BAB 10
Mempunyai komposisi yang sama
seperti bendalir tisu , juga sama Dibentuk daripada sambungan kapilari limfa.
dengan darah kecuali tiada eritrosit , Formed by joining of lymph capillaries .
Pengekalan aliran limfa secara berterusan oleh
platlet dan protein plasma.
Has the same composition as tissue fluid , pengecutan otot rangka .
also similar to blood except for the Lymph inside is kept flowing very slowly by the contraction
absence of erythrocytes , platelets and
plasma proteins . of the skeletal muscles .
Kehadiran injap mencegah aliran limfa daripada
2. Kapilari limfa / Lymph capillaries
berpatah balik.
Valves are present to prevent backflow of lymph.

Tiub hujung-buntu yang terletak di 5. Organ limfa / Lymph organs
ruang antara sel.
Blind-end tubes located in the spaces 4. Kapilari limfa / Lymph capillaries Termasuk limpa, tonsil, kelenjar
timus, apendiks dan sum-sum tulang.
between the cells. Include the spleen, tonsils, thymus gland,
Bendalir tisu yang tidak diserap appendix and bone marrow.

semula ke dalam aliran darah Bengkakan berada pada bahagian tertentu di Tonsil Kelenjar
disalurkan ke kapilari ini. sepanjang salur limfa . Tonsils timus
The tissue fluid which is not reabsorbed The swellings found at intervals along the lymph vessels . Apendiks Thymus
into the bloodstream drains into these Mengandungi limfosit yang penting dalam Appendix gland
capillaries. memusnahkan bekteria berbahaya. Sum-sum tulang
Contain lymphocytes that are important in destroying the Bone marrow Limpa
Cecair kekuningan yang terkumpul harmful bacteria . Spleen
ialah limfa .
The collected yellowish fluid is lymph .

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  Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan

Keperluan Sistem Limfa

The Necessity of the Lymphatic System

1. Mengembalikan bendalir tisu berlebihan ke sistem peredaran darah untuk mengekalkan keseimbangan
bendalir dalam badan.

Returns excess tissue fluid to the blood circulation to maintain the fluid balance in the body.

2. Mengangkut bahan larut lemak dari lakteal di vilus usus kecil ke dalam aliran darah.

Transports fat soluble substances from the lacteals in intestinal villi to the blood.

3. Melindungi kita daripada penyakit dengan menyaring patogen dalam limfa.

Protects us against disease by filtering out pathogens from the lymph.

10.8 Isu Kesihatan Berkaitan Sistem Limfa Manusia

Health Issues Relating to Human Lymphatic System

Kapilari Pengumpulan TP 3
Capillary bendalir tisu
Arteriol Accumulation Edema / Oedema
Arteriole of tissue fluid
Pembengkakan akibat pengumpulan
Venul bendalir tisu yang berlebihan dalam
Venule tisu badan.
Swelling due to the excess accumulation of
Sel tisu interstitial fluid within the tissues of the body.
Tissue cells
BAB 10
Tisu membengkak
akibat pengumpulan
bendalir limfa
Tissue swelling due
to accumulation of
lymph fluid

(a) Meningkatkan tekanan darah kapilari (b) Kekurangan protein plasma
Increased capillary blood pressure Decreased plasma protein

Wanita hamil , uterus yang membesar Kepekatan protein plasma rendah disebabkan oleh
memampatkan vena bahagian abdomen Low protein concentration in plasma due to
dan menambah tekanan darah kapilari pada
kaki menyebabkan edema. i) Penyakit hati menyebabkan gagal menghasilkan protein plasma.
Liver diseases cause failure to produce plasma proteins.
In pregnant women, the enlarged uterus compresses ii) Protein diet tidak mencukupi semasa kelaparan .
veins in the abdominal cavity adding to the capillary Insufficient dietary protein during starvation .
blood pressure in the woman’s lower limbs cause
odema.

(d) Salur limfa tersumbat

(c) Pesakit terlantar untuk tempoh Punca Obstruction of lymphatic drainage
yang lama. edema
Causes of Filariasis (elephantiasis) disebabkan
Individuals who are bedridden . oedema oleh jangkitan parasit (cacing filaria)
Otot tidak bergerak
Not moving the muscles . yang hidup dalam saluran limfa.
Lymphatic filariasis (elephantiasis) is caused

by infection with parasites (filarial worm)

which live in the lymphatic vessels.

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PRAKTIS Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan  

SPM 10

Soalan Objektif 3. Rajah 3 menunjukkan dua jenis sel darah.
1. Rajah 1 menunjukkan jantung manusia. Diagram 3 shows two types of blood cells.
Diagram 1 shows a human heart.
2018

X

X Y

Rajah 3/ Diagram 3

Rajah 1/ Diagram 1 Apakah sel X dan Y?

Apakah yang akan berlaku jika aliran darah tersumbat What are cells X and Y?
dalam X?
PQ
What will happen if there is blood flow blockage in X?
A Angin ahmar / Stroke A Eosinofil / Eosinophils Limfosit / Lymphocyte
B Penginfarkan miokardium / Myocardial infarction
C Tekanan darah rendah / Low blood pressure B Neutrofil / Neutrophils Monosit / Monocyte
D Hipertensi / Hypertension
C Eosinofil / Eosinophils Basofil / Basophils
2. Rajah 2 menunjukkan sistem peredaran manusia.
Antara yang berikut, urutan manakah betul tentang D Neutrofil / Neutrophils Limfosit / Lymphocyte
aliran darah dalam peredaran darah sistemik?
4. J, K, L dan M adalah peringkat-peringkat dalam
Diagram 2 shows human circulatory system. Which of the mekanisme pembekuan darah.
following shows the correct sequence of blood flow in the
systemic blood circulation? 2 018 J, K, L and M are the stages in blood clotting mechanism.

J Platlet bergumpal pada luka. BAB 10
Platelets clump at the wound.
Rajah 2/ Diagram 2 K Eritrosit terperangkap.
Erythrocytes are trapped.
A Ventrikel kiri → Vena kava → Tisu badan → Aorta L Trombokinase menukar protrombin kepada
→ Atrium kiri
Left ventricle → Vena cava → Body tissues → Aorta → Left trombin.
B atrium Thrombokinase converts prothrombin into thrombin.
Ventrikel kiri → Aorta → Tisu badan → Vena kava M Trombin menukarkan fibrinogen kepada fibrin.
C → Atrium kanan Thrombin converts fibrinogen into fibrin.
Left ventricle → Aorta → Body tissues → Vena cava →
D Right atrium Urutan manakah yang betul?
Ventrikel kanan → Vena kava → Atrium kiri → Which is the correct sequence?
Aorta → Tisu badan
Right ventricle → Vena cava → Left atrium → Aorta → A J → K → L → M C K → J → M → L
Body tissues B J → L → M → K D K → L → M → J
Ventrikel kanan → Aorta → Tisu badan → Vena
kava → Atrium kanan 5. Ali mempunyai jenis darah yang mengandungi antibodi
Right ventricle → Aorta → Body tissues → Vena cava→ A dan antibodi B telah mengalami kemalangan.
Left atrium Ali with a blood type which contains antibodies A and

antibodies B met with an accident.
Kumpulan darah manakah yang sesuai untuk
didermakan kepada Ali? KBAT Mengaplikasi
Which blood group is suitable to be donated to Ali?

A O C B
B A D AB

151

  Biologi  Tingkatan 4  Bab 10 Pengangkutan dalam Manusia dan Haiwan

Bahagian B
1. (a) Rajah 1 menunjukkan pertukaran bahan di jaringan kapilari.
Diagram 1 shows the material exchange in capillary bed.

Kapilari limfa Cecair tisu Limfa Sel tisu
Lymphatic capillary Tissue fluid Lymph Tissue cell
(blind-ended)
Sel darah merah
Arteriol Red blood cells
Arteriole
Venul
Venule

Tekanan Tekanan rendah
tinggi Low pressure
High
pressure Cecair tisu meresap masuk
ke dalam kapilari
Plasma meresap keluar Tissue fluid enters capillary
Plasma squeezed out

Rajah 1/ Diagram 1

Nyatakan satu contoh nutrien dalam darah dan terangkan bagaimana nutrien boleh dihantar ke sel.
State one example of nutrient in the blood and describe how the nutrient can be delivered to the cells. [10 markah / marks]

(b) Rajah 2 menunjukkan pengaliran darah dalam arteri normal dan pengaliran darah dalam arteri yang mempunyai plak.
Diagram 2 shows blood flow in a normal artery and blood flow in an artery with plaque.

2018

BAB 10 Dinding arteri Aliran darah
Artery wall berkurang
Decreased
blood flow

Arteri Plak
membekal Plaque
darah ke Arteri sempit
kaki Narrowed artery
Arteries
supplying
Keratan rentas arteri blood to leg
Artery cross-section

Rajah 2/ Diagram 2

Apabila darah mengalir ke bahagian badan yang tertentu berkurang, individu tersebut mungkin mengalami simpton
peredaran darah yang lemah. Terangkan sebab peredaran darah yang lemah dan kesannya kepada kesihatan.
When the blood flows to a specific part of the body is reduced, the individual may experience symptoms of poor blood circulation.

Explain the cause of poor blood circulation and the effect to the health. [10 markah / marks]

Kuiz 10

152

BAB Keimunan Manusia

11 Immunity in Humans

PETA Konsep

Keimunan Manusia

Immunity in Humans

Pertahanan Badan Jenis keimunan Isu Kesihatan
Body Defence Types of Immunity Health issues

Barisan Pertahanan Barisan Pertahanan Aktif Pasif AIDS
Pertama Ketiga Active Passive

First line of defence Third line of defence

Semula jadi Semula jadi
Naturally Naturally

Barisan Pertahanan Buatan Buatan BAB 11
Kedua Artificial Artificial

Second line of defence
Tindakan antibodi
Actions of antibody

Peneutralan Pengaglutinan Pemendakan Pengopsoninan Penguraian
Neutralisation Agglutination Precipitation dan fagositosis Lysis
Opsonisation and

phagocytosis

115533

  Biologi  Tingkatan 4  Bab 11 Keimunan Manusia

11.1 Pertahanan Badan

Body Defence TP 1

1. Keimunan adalah keupayaan badan untuk menentang jangkitan patogen atau antigen dengan
menghasilkan antibodi tertentu.
TP 4
Immunity is the body’s resistant to a pathogen or antigen by producing a specific antibody .

2. Antigen dan antibodi: Antibodi / Antibody

Antigens and antibodies:

Antigen / Antigens

Antigen
Antigen

Bakteria Virus
Bacterium Virus

(a) Molekul yang boleh merangsang gerak balas (a) Antibodi adalah imunglobulin , protein kompleks
yang dihasilkan oleh sel plasma limfosit dalam sistem
keimunan . keimunan.
Molecules that can stimulate an immune response.
Antibodies are immunoglobulins , complex proteins
(b) Biasanya adalah protein atau glikoprotein di produced by the plasma cells of lymphocytes in the immune
system.
membran plasma patogen.
They are usually proteins or glycoproteins in the plasma (b) Ia dibebaskan sebagai gerak balas terhadap jangkitan .

membrane of the pathogen. They are released in response to an infection .

(c) Antigen asing akan dikesan oleh sistem keimunan (c) Ia mempunyai bahagian berbentuk khusus yang
dan akan merangsang penghasilan antibodi . melengkapi bentuk antigen tertentu.

Foreigen antigen will be detected by the immune system They have a region with a specific shape that is complementary
and will stimulate the production of antibodies . to that of a particular antigen .

3. Tiga barisan pertahanan manusia TP 2

BAB 11 Three lines of human defence

(a) Barisan pertahanan pertama / First line of defence

Penghalang fizikal / Physical barriers Penghalang kimia / Chemical barriers Mekanisme pertahanan
tidak spesifik
Kulit / Skin Rembesan kulit dan Non-specific defence
mechanism
Membran mukus . membran mukus.
Mucous membranes Secretions of skin and mucous Bertindak terhadap
membrane. semua jenis patogen

(b) Barisan pertahanan kedua / Second line of defence Acts against all types of
pathogens
Demam / Fever
Keradangan / Inflammation Mekanisme pertahanan
Fagositosis / Phagocytosis spesifik
Specific defence
(c) Barisan pertahanan ketiga / Third line of defence
mechanism
Limfosit / Lymphocytes cells
Antibodi / Antibodies Bertindak terhadap jenis
patogen yang spesifik
Sel memori / Memory Acts against specific types
of pathogens

154

Biologi  Tingkatan 4  Bab 11 Keimunan Manusia  

Barisan Pertahanan Pertama

First Line of Defence:

• Barisan pertahanan pertama menghalang kemasukan organisma patogen ke dalam badan.

The first line of defence is to prevent the entry of pathogenic organisms into the body.

1 Penghalang fizikal: Kulit / Physical barrier: The skin Barisan Pertahanan TP 2
Badan Manusia
Sel mati / Dead cells: VIDEO 9 Human Body Defence
(a) Membentuk lapisan epidermis yang kuat dan sukar ditembusi oleh
Epidermis kulit
patogen . Skin epidermis
Formed a tough and impermeable epidermis layer to prevent the entry of

pathogens .
(b) Patogen di permukaan kulit disingkir apabila sel permukaan kulit

mengelupas dan digantikan oleh sel-sel baharu.
Pathogens on the skin surface are removed when these cells are constantly

shed and replaced by new cells from underneath.

2 Penghalang fizikal: membran mukus / Physical barrier: The mucous membrane TP 2

(a) Sel perembes mukus : Zarah debu dan patogen (b) Silia / Cilia
Mucus secreting cell: Dust particles and pathogen (i) Tindakan silia menyapu mukus ke
(i) Merembes mukus untuk
Ke arah farinks Mukus Silia arah farinks
memerangkap zarah debu To pharynx Mucus Cilia Their beating action sweeps mucus
dan patogen dalam udara
yang memasuki salur respirasi. towards the pharyns .
Secretes mucus to trap dust (ii) Mukus kemudian ditelan atau

particles and pathogens in the dibatuk keluar.
incoming air in the respiratory The mucus is then swallowed or

tract. coughed up.

3 Penghalang kimia / Chemical barriers TP 2 BAB 11

• Penghalang kimia adalah rembesan badan yang boleh membunuh atau menghalang pertumbuhan patogen .

Chemical barriers are secretions from our body that can kill pathogens or inhibit their growth.

Air mata B A Mengandungi asid hidroklorik - dapat membunuh patogen dalam makanan dan minuman.
Tears B Contains hydrochloric acid - destroys most pathogens in food and drink consumed.
A
Air liur C B Mengandungi lisozim – dapat membunuh patogen.
Saliva D Contains lysozyme - destroys most invaded pathogens.

Jus gastrik C Sebagai antiseptik - dapat membunuh patogen dan membentuk filem perlindungan di kulit.
Gastric juice An antiseptic - can kill pathogens and formed a protective film over the skin.

Sebum D Bersifat asid - dapat menghalang pertumbuhan patogen.
Sebum Acidic – can inhibit the growth of pathogens.

Rembesan vagina
Vaginal secretion

155

  Biologi  Tingkatan 4  Bab 11 Keimunan Manusia

Barisan Pertahanan Kedua

Second Line of Defence

1. Barisan pertahanan kedua digunakan untuk memerangi patogen yang telah memasuki badan.

Second line of defences is used to combat pathogens that have entered the body.

2. Phagocytosis adalah proses di mana fagosit dalam darah dan bendalir tisu menelan dan mencerna
patogen.

Phagocytosis is the process by which phagocytes in blood and tissue fluid engulf and digest the pathogens.

3. Dua jenis utama fagosit: neutrofil dan makrofaj .

Two main types of phagocytes: neutrophils and macrophages .

4. Peringkat-peringkat fagositosis TP 2
Stages of phagocytosis:

(a) Fagosit tertarik oleh (b) Fagosit menghulurkan pseudopodia Bakteria
bahan kimia yang Bacteria
dhasilkan oleh bakteria. mengelilingi bakteria dan
menelannya . 1
The phagocyte is attracted The phagocyte extends its pseudopodium
by the chemicals produced towards the bacterium to engulf it. 2
by the bacterium.

Pseudopodia 3 Fagosom
Pseudopodium Phagosome

(c) Penelanan bakteria (d) Fagosit bergabung dengan lisosom Lisosom 4 Jasad
membentuk di mana lisozim dirembes ke dalam Lysosome 5 residu
fagosom . fagosom. 6 Residual
body
Ingestion of the The phagocyte combines with a
lysosome which releases Iysozyme Bahan
bacterium forms 7 buangan
phagosome . into the phagosome.
Waste product

BAB 11 (e) Bakteria di dalam fagosom dicerna (f) Pembentukan jasad residu yang (g) Fagosit membebaskan bahan buangan
oleh lisozim . daripada sel.
mengandungi bahan tidak tercerna.
The bacterium inside the phagosome is Formation of residual body containing The phagocyte releases the waste
digested by the Iysozyme . products from the cell.
indigestible material.

5. Gerak balas keradangan TP 2
Inflammatory responses

(a) Keradangan adalah gerak balas badan terhadap rangsangan berbahaya, seperti patogen , sel yang rosak

dan sebatian toksik.

Inflammation is the body response to harmful stimuli, such as pathogens , damaged cells, and toxic compounds.

(b) Tisu mempunyai ciri kemerahan , membengkak , kepanasan dan kesakitan .

The tissues are characterised by redness , swelling , heat and pain .

(c) Gerak balas keradangan dimulakan oleh bahan kimia iaitu histamin terhasil daripada sel rosak .
Bahan kimia ini mempunyai kesan berikut:

An inflammatory response is initiated by the chemicals called histamines released by damaged cells. The chemicals

have the following effects:

156

1. Tisu yang rosak membebaskan histamin , Pin Biologi  Tingkatan 4  Bab 11 Keimunan Manusia  
alviraasnodim1hli)asedsTtnaaiiisrmnaugbihnyke,aavrtnlakagsakdonruioda.ssilelaaIinrkksaiiintmmbaedereramllnuarbaikknehuagb..dkaIinassitkekakanintar Luka Kulit
Wound
DvaamsoadgeildaDvluataiktsomiasons.adugilea.estTdiohrtneius.lsTesuahinesuecssr,reeinalechsraiiensstageasmihniisgnbtaeblomslooiondd,esfcl,oacwufalosueswe Skin
around tahreouwnoduthned.wound.
33). FFaaggoossititmemneelanneldaann mdeanncemrneancerna
patopgaetno,gseenl,msealtimdaanticdeabnisacnebsiissaan sisa sel.
engulf digest
sPeh la.gPohcaygteoscyetnegsulf and digest patahnodgens,
Histamin Patogen deadpcaethllsogaenndsc, edlleualadr dcebllrsisa.nd cellular debris.
Histamine Pathogen

Fagosit 4. Platlet bergerak
Phagocyte

2. Histamin2)mHeinstianmgkinatmkaenninkgektealtakapnanketkealappialanri , Platlet uk4e)nukltPueunallktauurtmalkdereatmdnrbiuaeektrnrauiguppetiilruaakprkaiipkialawriasan
lebih banpkyaeapmkilbaerfika, ugleaobnsiihdf abdraaanhnyamfkaekfrateogsroasppitkedemalunbaefrakkkuetaonr Platelet kalwukaasa. n luka.
darah mekraewsaspaknelluukaar. ke kawasan luka.
tPt hhleeathtwcePealloeaputtiselnclaldamerepytodsivltloeaarrsmoeyeuaoat.vloteof out of
HicsatapmillianreicHceslasiosiptnttialic,lnmargrreeiineaflaeessces,atrsoiteinrhnlsceegraienpsmatioesnoregtmrhetmeheeoawrpbpoehieulpiarntmhygdaoe.ogcafoybctileyittsyesoafanndd seal the
clotting factors into the wound.
wounded area.

6. Gerak balas keradangan menyebabkan / The inflammatory response leads to: BAB 11
(a) Luka menjadi kemerahan dan kepanasan akibat pengaliran darah meningkat.

The wound becomes red and hot due to the increased blood flow.

(b) Luka membengkak disebabkan pengumpulan bendalir tisu .

The wound is swollen due to the accumulation of tissue fluid .

(c) Terasa kesakitan kerana tekanan di tisu membengkak merangsang reseptor kesakitan pada kulit.

There is pain because the pressure built up in the swollen tissue stimulates the pain receptors in the skin.

(d) Nanah terbentuk di dalam luka. Ia terdiri daripada patongen dan fagosit yang mati.

Pus may form inside the wound. It consists of the remains of killed pathogens and dead phagocytes .

Demam / Fever

1. Demam adalah kenaikan suhu badan yang tinggi akibat jangkitan patogen . TP 2

A fever is an abnormally high temperature associated with infection .

2. Demam membantu memerangi jangkitan dengan mengurangkan kadar pertumbuhan mikrob (menyahaktif

aktiviti enzim mikrob).

Fever may help to combat infection by reducing the growth rate of microbes (via the inactivation of microbial enzymes)

3. Ini meningkatkan aktiviti metabolik sel badan dan gerak balas keimunan.

It may also increase metabolic activity in body cells and the immune response.

Mengaktifkan Bebaskan Merangsang Hasilkan Merangsang 42
Activate Release Stimulate Produce Trigger °C

41

40

38
39

36
37

35

Patogen Leukosit Sitokin Hipotalamus Prostaglandin Demam
Pathogens Leukocytes Cytokines Hypothalamus Prostaglandins Fever

157

  Biologi  Tingkatan 4  Bab 11 Keimunan Manusia TP 2

Barisan Pertahanan Ketiga

Third Line of Defence

1. Barisan pertahanan ketiga melibatkan sistem keimunan dan adalah pertahanan khusus .
The third line of defence is the immune system which is a specific defence.

2. Ini melibatkan gerak balas keimunan oleh limfosit .

This involves immune responses which are made by lymphocytes .

3. Apabila sel limfosit B diaktifkan, ia menjalani pembahagian dan membentuk sel-sel klon. Sel ini

membeza untuk membentuk:

An activated lymphocyte B cell divides to produce a large number of identical cells. Then the cells differentiate into:

(a) Sel-sel plasma – menghasilkan antibodi yang khusus terhadap antigen asing.

Plasma cells - which release antibodies to act against foreign pathogens.
(b) Sel-sel memori B – ‘mengingat’ jenis antigen asing.

Memory B cells - which ‘remember’the type of foreign antigen.

1 Makrofaj menelan patogen 2 Aktifkan sel B and sel T
Ingestion of antigen (pathogen) Activation of B cell and
by macrophage T cell

Sel B
B cell

BAB 11 Sel T 3 Pembentukan klon
T cell Formation of a clone

Sel plasma Sel memori B
Plasma cells Memory B cells
Merembes antibodi
Secrete antibodies Mengingat antigen asing
pada masa akan datang

Remember the
antigen for future encounters

11.2 Tindakan Antibodi

Actions of Antibodies

Tindakan antibodi terhadap antigen asing TP 1

Antibody action against foreign antigens

Antibodi bertindak terhadap patogen atau toksinnya dengan cara berikut:
Antibodies act against pathogen or their toxins in the following ways:

158

(a) Peneutralan / Neutralisation Biologi  Tingkatan 4  Bab 11 Keimunan Manusia  

Antibodi bertindak Toksin dibebaskan Antibodi bergabung dan TP 2
sebagai antitoksin . meneutralkan toksin.
Some antibodies act as oleh patogen. (e) Pengopsoninan dan fagositosis
Toxins released by They neutralise the toxins Opsonisation and phagocytosis
antitoxins . by binding to them.
pathogens. Fagosit menelan
toksin terneutral
(b) Pengaglutinan / Agglutination dengan lebih mudah.
Phagocyte engulfs
Antigen the neutralised toxins
Antigens more easily.

Antibodi Patogen Antibodi mengikat patogen Fagosit menelan
Antibodies Pathogen membolehkan pengumpalan . toksin dengan lebih
mudah.
Some antibodies help clump the Phagocyte engulfs
pathogens together. the pathogens more
easily.

(c) Pemendakan / Precipitation

Antibodi Antigen terlarut Antibodi bergabung dengan antigen Fagosit menelan BAB 11
Antibodies Soluble antigens terlarut membentuk mendakan .
Antibodies combine with soluble mendakan dengan
antigens form an insoluble precipitate.
lebih mudah.
Phagocyte engulfs
the precipitate more
easily.

(d) Penguraian / Lysis

Antigen Membawa Ini mengaktifkan
Antigens kepada
Leads to protein tertentu
Antibodi Patogen Sel terurai
Antibodies Pathogen Antibodi bergabung Cell Iysis dalam darah
dengan antigen .
Antibodies bind to dan mengurai

antigens on pathogen. patogen.
This activates
certain proteins in
blood and results
in lysis of the
pathogens.

159

  Biologi  Tingkatan 4  Bab 11 Keimunan Manusia

11.3 Jenis Keimunan

Types of Immunity

TP 4

Jenis keimunan / Types of immunity

Keimunan pasif / Passive immunity Keimunan aktif / Active immunity

Badan menerima antibodi dari sumber lain. Badan menghasilkan antibodi sendiri apabila
The body receives antibodies from another source. sistem keimunan diaktifkan.

The body produces its own antibodies when the
immune system is activated

a b Keimunan pasif a b Keimunan aktif
Keimunan pasif buatan Keimunan aktif buatan
semula jadi semula jadi
Artificial passive Artificial active
Naturally passive immunity Naturally active immunity
immunity immunity

BAB 11 (i) Keimunan diperoleh (i) Keimunan diperoleh (i) Keimunan diperoleh (i) Keimunan diperoleh
melalui suntikan daripada antibodi yang
daripada antibodi yang antiserum atau serum daripada antibodi yang dihasilkan oleh limfosit
dihasilkan oleh ibu yang mengandungi setelah diberi immunisasi
melalui plasenta atau antibodi yang dibuat dihasilkan oleh limfosit atau vaksinasi .
oleh individu lain.
susu ibu (kolostrum). setelah sembuh daripada Immunity provided by
Immunity provided from Immunity provided by jangkitan . antibodies made by
injection of antiserum or Immunity provided by lymphocytes as a result of
antibodies produced by serum contains antibodies antibodies made by immunisation or vaccination .
made by another individual. lymphocytes as a result of
mother via placenta or via infection  . (ii) Individu disuntik dengan
(ii) Suntikan diberi vaksin , iaitu patogen
breastmilk (colostrum). kepada seseorang (ii) Keimunan kekal
yang berpenyakit yang dilemahkan
(ii) Keimunan adalah atau berisiko tinggi selepas jangkitan atau mati, dan ini
sementara dan mendapat penyakit. Permanent immunity mengaktifkan sistem
singkat kepada bayi, keimunan.
The injection is given to a follows the infection. A person is injected with
iaitu dalam tempoh person who is infected
with disease or has a high (iii) Contoh: Keimunan vaccine , a weakened or
beberapa bulan pertama risk of getting the disease. terhadap cacar . dead pathogen and this

selepas dilahirkan. (iii) Keimunan adalah Eg. Immunity to chicken pox . activates the immune
segera dan sementara . system.
Temporary and short
immunity that can only last Immediate and temporary (iii) Keimunan ini adalah
for the first few months after immunity. berpanjangan .
birth.
(iv) Contoh: Serum The immunity lasts for a
anti-tetanus long time.

Eg. Anti-tetanus serum (iv) Contoh: Keimunan
terhadap campak and
TB .

Eg.: Immunity to measles
and TB .

160

11.4 Isu Kesihatan Berkaitan Keimunan Manusia Biologi  Tingkatan 4  Bab 11 Keimunan Manusia  
TP 2
Health Issues Related to Human Immunity

Sindrom Kurang Daya Tahan Penyakit (AIDS)

Acquired Immunodeficiency Immunodeficiency Syndrome (AIDS)

1. AIDS: Sindrom kurang daya tahan penyakit Disebabkan oleh 2. HIV: Virus Imunodefisiensi manusia
Acquired immunodeficiency syndrome Cause by Human immunodeficiency virus

( a) Penyebaran HIV (c) Kesan HIV ke atas mekanisme pertahanan badan BAB 11
The transmission of HIV Effects of HIV on the body’s defence mechanism

(i) Hubungan seks dengan orang yang terjangkit (i) HIV menyerang dan memusnahkan sel-sel limfosit.
melalui air mani atau cecair faraj . HIV attacks and destroys lymphocytes.

Unprotected sexual intercourse with an infected (ii) Sistem keimunan menjadi lemah dan terdedah
person via semen or viginal fluid . kepada jangkitan .

(ii) Darah tercemar semasa pemindahan darah. The immune system of a person is weakened and
Infected blood in blood transfusion . prone to infections.

(iii) Perkongsian jarum suntikan yang tercemar di (iii) Sistem keimunan yang lemah tidak dapat melawan
kalangan penagih dadah. jangkitan penyakit lain dengan berkesan.

Contaminated needles by intravenous drug users. A weakened immune system cannot fight other infections
effectively.

(b) Pencegahan AIDS
Prevention of AIDS

(i) Elakkan perhubungan seks secara rambang
Avoid casual sexual relationships.

(ii) Memastikan proses pemindahan darah yang selamat.
Practise safe blood transfusion.

(iii) Tidak berkongsi jarum suntikan dan barangan peribadi seperti pencukur , berus gigi dan pemotong kuku.
Do not share needles and other personal items like shavers , toothbrushes and nail clippers.

(iv) Program kesedaran untuk mendidik orang awam dan murid sekolah.
Educational programmes for public and school

161

  Biologi  Tingkatan 4  Bab 11 Keimunan Manusia SPM 11

PRAKTIS II Pemvaksinan membolehkan limfosit bayi
menghasilkan antibodi terhadap patogen tertentu
Soalan Objektif
1. Bagaimanakah keimunan pasif semula jadi diperolehi? Vaccination allow the baby’s lymphocytes produces
How natural passive immunity is obtained? antibodies against certain pathogens.
2018 A Melalui suntikan vaksin / By vaccination
III Suntikan vaksin mengandungi antibodi tertentu
B Suntikan antiserum / Injection of antiserum untuk melindungi daripada jangkitan patogen
C Sembuh daripada penyakit / Recovery from an infection
D Melalui plasenta / Through placenta The injected vaccine contains certain antibodies to
2. Mengapakah bayi yang baru dilahirkan perlu protect from infections
mendapatkan pemvaksinan?
2 019 Why is necessary for a new born baby to get vaccination? IV Antibodi yang terhasil akan kekal dalam aliran
I Pemvaksinan dapat melindungi bayi daripada darah bayi

semua jenis jangkitan The antibodies produced will remain in the baby’s blood
Vaccination can protect the baby from all infections stream.
A I dan II / I and II C II dan IV / II and IV
B I dan III / I and III D III dan IV / III and IV

Bahagian B
1. Rajah 1 menunjukkan dua kaedah bagaimana bayi memperoleh keimunan terhadap penyakit.
Diagram 1 shows two methods on how the body obtains immunity against diseases.

BAB 11 Kaedah 1 / Method 1 Kaedah 2 / Method 2

Rajah 1/ Diagram 1

(a) (i) Takrifkan keimunan. [2 markah / marks]
Define immunity

(ii) Banding keimunan yang diperoleh oleh bayi melalui dua kaedah ini. [8 markah / marks]
Compare the immunities obtained by the baby through these two methods.

(b) Human immunodeficiency Virus (HIV) ialah virus yang menyerang sistem pertahanan badan dan menyebabkan
Acquired Immunodeficiency Syndrome (AIDS). Terangkan apakah AIDS, kesan dan cara mengelakkan dari
dijangkiti.
Human immunodeficiency Virus (HIV) is a virus that attacks the human immune system and causes Acuired Immunodeficiency
Syndrome (AIDS). Explain what is AIDS, its effects and how the disease can be prevented. [10 markah / marks]

Kuiz 11

162

BAB Koordinasi dan Gerak Balas dalam Manusia

12 Coordination and Response in Humans

PETA Konsep

Koordinasi dan Gerak Balas Dalam Manusia
Coordination and Response in Humans

Sistem Saraf Sistem endokrin
Nervous System Endocrine system

Saraf SistemSaraf Pusat Isu Kelenjar Isu
Periferi Central nervous kesihatan endokrin kesihatan
Peripheral system Endorine
nervous Health Health
system Issue gland issue

Saraf Otak Saraf tunjang Sklerosis Hipotalamus
spina Brain Spinal cord berganda Hypothalamas
Spinal Multiple
nerve Serebrum Akar dorsal sclerosis Pituitari Kekerdilan Hipotiroidisme
Cerebrum Dorsal root Pituitary Dwarfism Hypothyroidsm
Saraf Kelenjar pituitari Akar ventral Alzheimer Tiroid
kranium Pituitary gland Ventral root Alzheimer Thyroid Kegergasian Diabetes
Cranial Serebelum Pankreas Gigantism mellitus
Cerebellum Parkinson Pancreas Diabetes BAB 12
nerve Hipotalamus Parkinson Adrenal Hypertiroidisme mellitus
Hypotalamus Adrenal Hyperthyroidism
Medula oblongata Lou Gehrig Diabetes
Medulla oblongata Lou Gehrig Ovari insipidus
Ovary Diabetes
Testis insipidus
Testes
Neuron ADHD
Neurone ADHD

Neuron deria Autisme
Sensony neurons Autism
Lumpuh otak
Neuron motor Cerebral palsy
Motor neurone Epilepsi
Epilepsy
Neuron geganti
Relay neurone

116633

  Biologi  Tingkatan 4  Bab 12 Koordinasi dan Gerak Balas dalam Manusia

12.1 Koordinasi dan Gerak Balas

Coordination and Response

Komponen dalam koordinasi manusia TP 1

The main components in human coordination rangsangan dan memberi gerak balas yang sesuai.

1. Organisma berkeupayaan mengesan stimuli and giving appropriate responses .

Organisms have the ability of detecting

2. Suatu rangsangan akan dikesan oleh reseptor deria. Reseptor akan menghantar impuls saraf ke

pusat integrasi (otak). Pusat integrasi akan menghantar impuls saraf kepada efektor (otot) untuk

menghasilkan gerak balas yang sesuai.

A stimulus is detected by sensory receptors . The receptors send out nerve impulses to the control centre (e.g. brain).
The control centre sends out nerve impulses to an effector (e.g. muscles) to produce an appropriate response .

Rangsangan Neuron deria Neuron motor TP 2
Sensory neuron Motor neuron
dalam dan luar. Gerak balas
Internal and external Response

stimuli . SReensseoprytorrecdeeprtioar PInutesgarat tiinntgeCgreanstrie

Rangsangan akan dikesan oleh Efektor / Effectors

reseptor deria. Reseptor deria untuk Otot (Efektor) Pusat integrasi menghantar impuls
kesakitan Muscle (Effector) saraf kepada efektor ( otot
A stimulus is detected by sensory Sensory receptor for pain atau kelenjar ) untuk menghasilkan
receptors .

Reseptor akan menghantar impuls Arah impuls gerak balas yang sesuai.
Impulse direction The integrating centre sends out nerve
saraf ke pusat integrasi ( otak impulses to an effector ( muscles or

dan saraf tunjang). glands ) to produce an appropriate
The receptors send out nerve impulses response .
to the integrating centre (the brain and
BAB 12 SCeisntteraml nsearvraouf spusyssatet m
spinal cord).

Rangsangan Luar dan Rangsangan Dalam TP 4

External and Internal Stimuli

Rangsangan luar / External Stimuli Keperluan bergerak balas terhadap rangsangan luar dan
rangsangan dalam
1. Cahaya / Light 6. Suhu / Temperature
7. Tekanan / Pressure The necessity to respond to external and internal stimuli
2. pH / pH Sound 8. Sentuhan / Touch
3. Bunyi / Smell 9. Kelembapan / Humidity a) Untuk organisma menyesuaikan diri dengan perubahan
4. Bau / persekitaran.

Rangsangan 5. Rasa / Taste To enable organisms to adapt to the environmental changes.
Stimuli b) Untuk melindungi organisma daripada bahaya .
Rangsangan dalam / Internal stimuli To protect the organisms from danger .
c) Untuk memastikan kemandirian organisma.
1. Aras gula dalam darah / Blood sugar level To ensure the survival of organisms.
2. Tekanan osmosis darah / Blood osmotic pressure d) Untuk mengawal atur persekitaran dalaman secara
3. pH darah / Blood pH
4. Suhu badan / Body temperature homeostasis .
5. Kandungan oksigen darah / Blood oxygen content To regulate the internal environment through homeostasis .

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Jenis Reseptor Deria

Type of Sense Receptor

• Reseptor dalam organ deria dan rangsangan yang dikesan oleh setiap jenis reseptor: TP 2

The receptors present in the sense organs and the stimulus detected by each type of receptor:

Jenis reseptor Organ deria Rangsangan dikesan

Type of receptor Sense organ Stimulus detected

Kemoreseptor Hidung / Nose Bahan kimia dalam udara / Chemicals in air
Chemoreceptor Lidah / Tongue Bahan kimia dalam udara / Chemicals in food

Mekanoreseptor Telinga / Ears Getaran bunyi / Sound vibrations
Mechanoreceptor Kulit / Skin Tekanan / Pressure , Sentuhan / Touch
Mata / Eyes Cahaya / Light
Fotoreseptor / Photoreceptor

Termoreseptor / Thermoreceptor Kulit / Skin Perubahan suhu / Changes in temperature

Baroreseptor Salur darah Perubahan tekanan darah / Changes in blood pressure
Baroreceptor Blood vessels

Nosireseptor / Nocireceptor Kulit / Skin Kesakitan / Pain

12.2 Sistem Saraf

Nervous System

Organisasi Sistem Saraf Manusia

Organisation of Human Nervous System

1. Sistem saraf / Nervous system TP 1

Sistem saraf pusat Sistem saraf perifefri
Central Nervous System (CNS) Peripheral Nervous System (PNS)

Otak Saraf tunjang Sistem saraf soma Sistem saraf autonomi BAB 12
Brain Spinal cord (tindakan terkawal )
Somatic nervous system (tindakan luar kawal )
Autonomic nervous system
( voluntary actions) ( involuntary actions )

Bahagian simpatetik Bahagian parasimpatetik
Sympathetic division Parasympathetic division

2. Sistem saraf manusia terdiri daripada dua bahagian utama: saraf tunjang . .

The human nervous system consists of two main parts: and the spinal cord

(a) Sistem saraf pusat (SSP), yang terdiri daripada otak dan

The central nervous system (CNS), which consists of the brain

(b) Sistem saraf periferi (SSP), yang terdiri daripada saraf kranium dan saraf spina . nerves.

The peripheral nervous system (PNS), which consists of cranial nerves and spinal

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3. (a) Otak (c) Saraf kranium Sistem saraf periferi
Brain Cranial nerve Peripheral nervous system
Sistem saraf pusat
Central nervous (b) Saraf tunjang (d) Saraf spina
system Spinal cord Spinal nerve

Otak / The brain TP 1

• Otak manusia terdiri daripada empat bahagian utama: (b) Serebrum / Cerebrum
(c) Serebelum / Cerebellum
The brain consists of four main parts: (d) Medula oblongata / Medulla oblongata

(a) Hipotalamus
Hypothalamus

(e) Kelenjar pituitari
Pituitary gland

1. Serebrum / The cerebrum TP 2
(a) Bahagian otak yang paling besar . / The Largest part of the brain.
(b) Ia mempunyai lapisan luar iaitu korteks serebrum , yang berlipat-lipat untuk menambahkan luas permukaan.
It has an outer layer called the cerebral cortex , which is highly folded at the surface to increase surface area .

(c) Fungsi / Functions:
(i) Ia mempunyai kawasan deria yang menerima dan mengintegrasi input deria daripada semua organ deria.
It contains sensory areas that receive and integrate the sensory input from all sense organs.
(ii) Ia mempunyai kawasan motor , untuk mengawal semua tindakan terkawal , contohnya bercakap dan menulis.
It has motor areas to control all voluntary actions, e.g. speaking and writing.

BAB 12 (iii) Ia mengawal keupayaan mental termasuk: .
It controls the mental abilities including:

• Pemikiran dan tindakan sedar / Conscious thoughts and actions
• Gerak balas beremosi / Emotional responses

• Kecerdasan , pertimbangan , penghakiman dan membuat keputusan .
Intelligence , reasoning , judgement and decision making.

• Pembelajaran, ingatan , kemahiran bahasa, imaginasi, bakat seni dan personaliti
Learning, memory , language skills, imagination, artistic talent and personality .

2. Serebelum / The cerebellum 3. Medula oblangata / The Medulla oblongata
(a) Kordinasi dan mengawal pengerakan otot seperti: (a) Mempunyai pusat pengawalan termasuk:
Coordinates and controls muscular movements such as: Has centres for regulating including:

(i) Mengkordinasi pengecutan dan pengenduran otot (i) Mengawal tindakan luar kawal seperti denyutan
rangka semasa berjalan dan berlari. jantung , pernafasan , peredaran dan tekanan darah .

Coordinating contraction and relaxation of antagonistic Controls involuntary actions, such as heartbeat , breathing ,
skeletal muscle when walking and running. circulation and blood pressure.

(ii) Mengekalkan kedudukan dan keseimbangan (ii) Pusat refleks bagi tindakan refleks , contoh merembes air
badan, contohnya semasa menunggang basikal. liur, menelan , batuk , bersin dan muntah .

Maintaining body position and balance , such as when The reflex centre for for many refles actions, e.g. saliva
riding a bicycle. secretion, swallowing , coughing , sneezing and vomiting .

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4. Kompleks hipotalamus dan pituitari / The Hypothalamus and pituitary complex
(a) Hipotalamus mengawal mekanisme homeostasis dalam badan.
Hypothalamus controls homeostatic mechanism in the body.

(i) Pusat kawalan bagi mengesan keletihan, kelaparan , dahaga , suhu badan, keseimbangan air dan tekanan

darah.
Regulating centre for sleep, hunger , thirst , body temperature , water balance and blood pressure .

(b) Mengawal rembesan sesetengah hormon dari kelenjar pituitari dan bertindak sebagai pautan penting di antara sistem saraf dan
sistem endokrin .
Controls the release of several bormones from the pituitary gland and acts as an important link between the nervous and endocrine systems.

Saraf Tunjang

The Spinal Cord

1. Saraf tunjang terletak di dalam turus vertebra . TP 1 Saraf tunjang
Spinal cord
The spinal cord is located within the vertebral column . Vertebra
Vertebra
2. Kawasan luaran saraf tunjang terdiri daripada jirim Saraf spina
putih . Kawasan dalaman berbentuk H terdiri daripada Spinal nerve

jirim kelabu .

The outer region of the spinal cord is made up of white
matter. The inner H-shaped region is made up of grey

matter.

a b
Jirim kelabu / Grey matter Jirim putih / White matter
• Terdiri daripada akson neuron geganti tanpa salut mielin • Terdiri daripada gentian saraf ( akson ) bagi neuron
dan badan sel neuron motor. bersalut mielin .
Consists unmyelinated axons of interneurons and the cell bodies Consists of nerve fibres ( axon ) of myelinated neurones.
of motor neurones.
c d dorsal / Dorsal root
Neuron deria Akar
Sensory neurone
• Terdiri daripada akson neuron deria.
e
Neuron geganti Contains the axons of the sensory neurons. BAB 12
Relay neurone
f
Ganglion akar dorsal

Dorsal root ganglion
• Terdiri daripada badan sel neuron deria.

Contains cell bodies of sensory neurones.

Fungsi Saraf Tunjang TP 2

Functions of the Spinal Cord

1. Menghantar impuls saraf di antara otak dan bahagian badan yang lain.

It relays nerve impulses between the brain and other parts of the body.

2. Adalah pusat refleks untuk kebanyakan tindakan refleks.

It is the reflex centre for many reflex actions.

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Sistem Saraf Periferi

Peripheral Nervous System

1. Peranan: untuk memastikan kecekapan komunikasi antara reseptor deria, CNS dan efektor .

Role: to ensure rapid communication between the sensory receptors , the SSP and the effectors .

2. Neuron reseptor membawa impuls dari reseptor ke dalam SSP. Neuron motor membawa impuls keluar

dari SSP ke efektor di badan. receptors into the CNS. The motor neurones carry impulses out

The sensory neurones carry impulses from the
from the CNS to the effectors in the body.

12.3 Neuron dan Sinaps

Neurone and Synapse

1. Neuron adalah unit asas sistem saraf. / Neurones are the basic unit of the nervous system. TP 1

2. Terdapat tiga jenis neuron yang berbeza. / There are three different types of neurones.
(a) Neuron deria yang membawa impuls saraf dari reseptor deria ke sistem saraf pusat .

Sensory neurones that carry nerve impulses from a sensory receptor to the central nervous system.

(b) Neuron motor yang membawa impuls saraf daripada SSP ke efektor ( otot atau kelenjar
endokrin)

Motor neurones that carry nerve impulses from the CNS to effectors ( muscles or endocrine glands ).

(c) Neuron geganti yang menghubungkan neuron deria dan neuron motor .

Relay neurones that connect sensory and motor neurones.

Struktur Neuron TP 2

Structure of Neurone

Badan sel Dendron (a) Neuron deria
Sensory neurone
Cell body Dendron
Mempunyai dendron yang
Akson panjang dan akson yang
pendek .
(a) Axon
Has a long dendron and a
Sel reseptor short axon.

Receptor cells

BAB 12 Nodus Ranvier Salut mielin

Node of Ranvier Myelin sheath

Hujung sinaps (b) (b) Neuron geganti / Relay neurone

Synaptic end Mempunyai dendron dan akson yang pendek . Arah impuls
Has short dendrons and short axons. Direction of
impulse

(c) Badan sel Nodus Ranvier
Node of Ranvier
Cell body

(c) Neuron motor / Motor neurone

Hujung sinaps Mempunyai dendron yang sangat pendek
Synaptic ending dan akson yang panjang .
Has very short dendrons and a long
Akson Salut mielin axon.
Axon Myelin sheath

Dendrit Dendron
Dendrite Dendron

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Komponen Neuron Biologi  Tingkatan 4  Bab 12 Koordinasi dan Gerak Balas dalam Manusia  
TP 2
Components of Neurones

1 2 3 4 5

Badan sel Akson Salut mielin Dendrit Terminal sinaps
Cell body Axon Myelin sheath Dendrites Synaptic terminal

Mengandungi nukleus , Membawa impuls Lapisan berlemak di • Menerima rangsangan Menghantar isyarat ke
banyak mitokondria saraf menjauhi sekeliling akson daripada neuron lain. sel otot , kelenjar
dan ribosom . badan sel. sebagai pelindung dan atau dendrit neuron lain.
Contains the nucleus , The Receive stimuli from
many mitochondria and Carries nerve impulses penebat akson. other neurones . Transmits the signals
ribosomes . away from the cell A layer of fatty material to the muscle cells,
surrounding axon to • Membawa impuls saraf
body. protect and insulate the axon. ke badan sel. glands or dendrites of
other neurones.
Carry nerve impulses towards
the cell body.

a b c d

Rangsangan Reseptor mengesan Reseptor mencetus impuls saraf Impuls saraf dihantar dari neuron deria ke
bunyi rangsangan di neuron deria . neuron geganti di dalam otak .
Sound stimulus Receptors detect the Receptors trigger nerve impulses in The nerve impulses pass from sensory neurones to
stimulus the sensory neurones.
Bunyi relay neurones in the brain .
Sound

Neuron deria e
Sensory neurone
Neuron geganti System saraf pusat : otak
Relay neurone Central nervous system:The brain

• mengintegrasi dan menginterpretasi
impuls saraf.

Integrates and interprets the nerve impuls .
• Menghantar impuls saraf ke neuron

motor .
Sends out nerve impulses to the motor

neurones.

h Neuron motor f BAB 12
Motor neurone
Gerak balas : Tangan Neuron motor membawa impuls saraf
membuka pintu. g ke efektor .
Response : The hand opens
the door. Efektor: pengecutan otot di tangan menghasilkan Motor neurones carries the nerve impulses to
gerak balas . effectors .

Effectors: contraction of muscles in the hand carries out
the responses .

Sinaps

Synapse

• Sinaps adalah tempat pertemuan antara dua atau lebih neuron , di mana satu neuton dapat berkomunikasi
dengan neuron lain.

A synapse is a junction between two or more neurones , when one neurone can communicate with another neurone.

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Dendron Akson TP 2

Dendron Axon

Penghantaran impuls merentasi sinaps
Transmission of nerve impulses across the synapse

1. Impuls saraf tiba di bonggol sinaps.
A nerve impulse reaches the synaptic knob.

Akson / Axon 2. Merangsang vesikel sinaps untuk bergerak ke dan
bergabung dengan membran pra-sinaps .
Mitokondria / Mitochondrion
Vesikel sinaps It triggers the synaptic vesicles to move to and fuse with

Synaptic vesicle the pre-synaptic membrane.

Bonggol sinaps 3. Neurotransmiter (contoh asetilkolina) dibebaskan
secara eksositosis. (eg. Acetylcholine) is released by
Synaptic knob
Neurotransmitters
Membran pre-sinaps exocytosis.

Pre-synaptic membrane 4. Mitokondria menjana tenaga bagi penghantaran
impuls saraf secara aktif melintasi sinaps.
Ruang sinaps
The mitochondria generate energy for the active
Synaptic cleft
transmission of nerve impulses across the synapse.
Reseptor / Receptor
BAB 12 Membran pos-sinaps 5. Molekul neurotransmiter meresap merentasi
ruang sinaps dan bergabung dengan reseptor
Post-synaptic membrane
protein di membran pos-sinaps .
7. Pemindahan maklumat merentasi ruang sinaps melibatkan The neurotransmitter diffuses across the synaptic
pertukaran impuls elektrik ke impuls kimia dan berlaku
sahala sahaja. cleft and binds to specific protein receptors on the

The transmission of information across the synaptic cleft involves conversion post-synaptic membrane.
of the electrical impulse to chemical impulse and is in one
direction only. 6. Gabungan neurotransmiter kepada reseptor mencetus
impuls elektrik yang baharu.

The binding of neurotransmitters to the receptors leads to
generation of a new electrical impulse .

Kepentingan Sinaps TP 3

The Importance of the Synapses

1. Untuk memastikan impuls saraf bergerak dalam satu arah sahaja.

To ensure that nerve impulses travel in one direction only.

2. Untuk membenarkan neuron berkomunikasi dengan neuron yang lain.

They allow a neurone to communicate with many other neurones.

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12.4 Tindakan Terkawal dan Tindakan Luar Kawal

Voluntary and Involuntary Actions

Perbandingan antara tindakan terkawal dengan tindakan luar kawal: TP 4

Comparison of voluntary and involuntary actions:

Jenis Gerak Balas yang dikoordinasikan / Types of coordinated Responses

Tindakan terkawal / Voluntary actions Dikawal oleh Tindakan luar terkawal / Involuntary actions
Controled by
(a) Korteks serebrum (a) Medula oblongata dan hipotalamus
Cerebral cortex Ciri-ciri
Characteristics Medulla oblongata and hypothamalus

(b) Di bawah kawalan sedar Contoh (b) Berlaku secara automatik tanpa kawalan sedar
Under conscious control Examples
Occurs automatically without any conscious control
Laluan
(c) Berjalan  ,  bercakap Pathway (c) Peristalsis  ,  denyutan jantung  ,  sentakan lutut
Walking  ,  talking Peristalsis  ,  heartbeat  ,  knee-jerk

(d) Rangsangan Reseptor (d) Rangsangan Reseptor
Stimulus Receptors Stimulus Receptors

Neuron deria / Sensory neuron Neuron deria / Sensory neurone

Korteks serebrum di otak Medula oblongata  ,  hipotalamus  ,  saraf tunjang
Cerebral cortex in the brain Medulla oblongata  ,  hypothalamus  ,  spinal cord

Neuron motor / Motor neurone Neuron motor / Motor neurone

Gerak balas Efektor Gerak balas Efektor
Response Effectors Response Effectors

(e) Gerak balas otot rangka Melibatkan (a) Gerak balas otot licin dan kelenjar
The reaction of skeletal muscles Involve
The reaction of smooth muscles and glands

Tindakan refleks / Reflex action

1. Tindakan refleks adalah gerak balas pantas dan automatik terhadap sesuatu ramgsangan . BAB 12

A reflex action is an inborn, rapid and automatic response to a stimulus .

2. Semua tindakan refleks adalah luar kawal kerana tidak melibatkan serebrum .

All reflex actions are involuntary because they do not involve the cerebrum .

3. Laluan saraf untuk refleks ini adalah arka refleks .

The nervous pathway for such reflexes is called a reflex arc .

4. Laluan tersingkat supaya refleks berlaku dengan cepat dan menghindarkan bahaya .

It is as short as possible so that the reflex is rapid and protects us from danger .

Contoh tindakan refleks / Example of reflex action Bahagian SSP yang terlibat / Parts of CNS involved

(a) Refleks penarikan / Withdrawal reflex (a) Saraf tunjung / Spinal cord
(b) Refleks sentakan lutut / Knee jerk reflex (b) Saraf spina / Spinal nerves
(c) Rembesan saliva, menelan dan batuk (c) Medula oblongata
Saliva secretion, swallowing and coughing Medulla oblongata

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Refleks Menarik Tangan / The Withdrawal Reflex

• Arka refleks yang melibatkan tiga neuron (neuron deria , neuron gaganti dan neuron motor ).

A reflex arc involves the three neurones ( sensory neurone, relay neurone and motor neurone).

1. Tangan tersentuh objek yang tajam .

The hand touches a sharp object. Dari otak Ke otak
From brain To brain

2. Reseptor kesakitan di kulit dirangsang dan mencetuskan impuls 5 5 Neuron motor
Motor neurone
saraf.
Pain receptors in the skin are stimulated and they generate nerve impulses . 4

3. Impuls saraf bergerak sepanjang neuron deria ke saraf tunjang .
Nerve impulses travel along the sensory neurone to the spinal cord .

4. Impuls saraf bergerak sepanjang neuron geganti dan neuron
motor ke otot tangan.

Nerve impulses travel along the relay neurone and the motor

neurone to the arm muscle .

5. Otot tangan (efektor) mengecut . Neuron deria Saraf tunjang
The arm muscle (effector) contracts . Sensory neurone Spinal cord
3
Neuron geganti
6. Tangan tertarik untuk mengelakkan kecederaan. 12 Relay neurone
The hand withdraws to prevent damage.

Sentakan Lutut / The Knee Jerk Reflex

1. Arka refleks yang hanya melibatkan neuron deria dan neuron motor .

A reflex arc involves only a sensory neurone and a motor neurone.

2. Refleks sentakan lutut membantu mengekalkan postur dan keseimbangan .

The knee jerk reflex helps maintain posture and balance .

BAB 12 Ke otak Neuron deria (a) Tendon di bahagian bawah tempurung lutut diketuk.
To brain Sensory neurone The tendon just below the knee cap is tapped.

32 (b) Reseptor regang di otot kaki dirangsang.
Stretch receptor in the upper leg muscle is stimulated

Saraf tunjang Neuron motor (c) Impuls saraf bergerak di sepanjang neuron deria .
Spinal cord Motor neurone Nerve impulses travel along the sensory neurone.

4 5 (d) Impuls saraf bergerak sepanjang neuron
1 motor ke otot kaki.

Nerve impulses travel along the motor neurone to
the leg muscle.

(e) Otot kaki (efektor) mengecut .
The leg muscle (effector) contracts .

(f) Kaki menendang .
The leg kicks .

6

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12.5 Isu Kesihatan Berkaitan Sistem Saraf Manusia

Health Issues Related to Human Nervous System TP 3
Masalah berkaitan sistem saraf

Nervous system disorders

Sklerosis Penyakit Penyakit Lou Gehrig / Autisme Epilepsi
berganda Alzheimer Parkinson Amyotrophic Autism Epilepsy
Multiple Alzheimer’s Parkinson’s Lateral Sclerosis
sclerosis • Masalah • Kejang otot kaki
disease disease (ALS) kemahiran dan tangan yang
• Kekejangan sosial tidak terkawal
otot • Hilang • Ketaran pada • Kesukaran
pertimbangan lengan, rahang, berjalan . Impaired social Uncontrollable
muscle kaki dan muka skills Jerking movements
spasms Loss of reasoning semasa bergerak Difficulty of the arms and
walking . • Kesukaran legs
• kehilangan • Hilang Tremors or hubungan mata
koordinasi dan kebolehan trembling (arms, • Kelemahan pada • Tidak sedar atau
keseimbangan mengurus diri jaws, legs and kaki dan Poor pengsan
sendiri face) tangan eye contact
loss of Loss of
coordination and Loss the ability • Kelemahan Weakness in leg • Melakukan consciousness
balance to care for otot and hand perbuatan
oneself berulang or awareness
Weak muscle • Masalah
• Menjadi keliru bercakap atau Repetitive motor
Become • Masalah menelan behaviours
keseimbangan
confused Slurred speech or • Kurang perasaan
dan koordinasi trouble swallowing empati
• Hilang daya Impaired
ingatan • Kesukaran Have problems
balance and mengekalkan feeling empathy
Memory loss coordination . postur yang baik for others

Difficulty keeping
good posturs .

Kesan Penyalahgunaan Dadah dan Alkohol Terhadap Koordinasi dan Gerak Balas Manusia

The Effects of Drug and Alcohol Abuse on Human Coordination and Response

(a) Dadah adalah bahan kimia yang boleh menjejaskan proses dalam organisma. Penyalahgunaan alkohol BAB 12
Drugs are chemicals that can affect processes in an organism. Alcohol abuse

Ubat perangsang Dadah (e) Mengganggu sistem saraf (a) Melambatkan tindakan refleks .
Stimulants Drugs dan tindakan sinaps . Slows down reflexes .

(b) Meningkatkan aktiviti otak. Interferes the nervous system (b) Menggangu keseimbangan dan
increases brain activities. and synapse . kawalan otot , mengakibatkan
penglihatan dan ucapan yang kabur .
(c) Membebaskan lebih banyak Ubat penenang
neurotransmiter . Depressants Interferes the balance and muscular
(f) Perlahankan aktiviti control, leads to blurred vision and
More neurotransmitter to be
sistem saraf pusat. slurred speech.
released. Slow down the activity of
(c) Menggangu mental .
(d) Denyutan jantung the central nervous system Mental disturbances.
bertambah, tekanan darah
(d) Boleh merosakkan hati dan sel-sel
meningkat dan berasa otok dalam jangka masa yang
teruja .
panjang.
Heartbeats faster, blood Over a prolonged period, can cause the
pressure rises and feel exited .
destruction of brain and liver cells.

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12.6 Sistem Endokrin

Endocrine system

Sistem Endokrin Manusia TP 2

The Human Endocrine System

1. Sistem endokrin terdiri daripada kelenjar endokrin yang merembeskan hormon . darah .

The endocrine system consists of endocrine glands, which secrete hormones .

2. Kelenjar endokrin adalah kelenjar tanpa duktus yang merembes hormon ke dalam

Endocrine glands are ductless glands that secrete hormone into blood .

(a) Sel-sel di kelenjar endokrin Vesikel rembesan Sel endokrin (c) Hormon diangkut dalam darah
merembes hormon. Secretory vesicle Endocrine cell ke seluruh bahagian badan .
Molekul hormon
Cells in endocrine gland secrete Hormone molecules The hormones are transported in the
hormones
blood to all parts of the body .

(b) Hormon meresap ke dalam Salur darah (d) Sel-sel di organ sasaran tertentu menerima
darah . Blood vessel
hormon dan perubahan berlaku.
The hormones diffuse into the Sel target Cells in specific target organs receive hormones
Target cell
blood. and changes occur.

3. Kebanyakan hormon adalah protein atau steroid berfungsi sebagai isyarat kimia dan dihasilkan dalam
jumlah yang kecil .
in nature serve as chemical messengers and are produced in very
Hormones are mostly protein or steroid
small amounts.

4. Tempoh keberkesan hormon adalah lama .

The duration of effect of hormone is usually long-lasting .

Sistem Endokrin Manusia TP 1

BAB 12 The Human Endocrine System Hipotalamus
Hypothalamus
Kelenjar pituitari
Pituitary gland Kelenjar tiroid
Thyroid gland

Pankreas Kelenjar adrenal
Pancreas Adrenal gland

Testis Ovari
Testis

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Fungsi Hormon dalam Manusia Biologi  Tingkatan 4  Bab 12 Koordinasi dan Gerak Balas dalam Manusia  
TP 3
The Role of Hormones in Humans

Kelenjar endokrin Hormon Fungsi
Endocrine gland Hormone Function

1. Hipotalamus (a) Hormon perembes (i) Merangsang lobus anterior pituitari untuk menghasilkan hormon perangsang
Hypothalamus gonadotropin folikel (FSH) dan hormon peluteinan (LH), pada lelaki dan perempuan.

2. Lobus anterior (GnRH) Stimulates the anterior pituitary to produce follocle stimulating hormone (FSH) and
pituitari Gonadotropins – luteinising hormone (LH), in both males and females.

Anterior pituitary releasing hormone (GnRH)
gland
(a) Hormon (i) Merangsang pertumbuhan , sintesis protein dan metabolisme lemak.
3. Lobus posterior pertumbuhan
pituitari Stimulates growth , protein synthesis and fat metabolism.
Growth hormone (GH)
Posterior pituitary
gland (b) Hormon (i) Merangsang perkembangan folikel di ovari wanita.
perangsang folikel
4. Kelenjar tiroid Stimulates the development of follicles in the ovaries in females.
Thyroid gland Follicle stimulating
5. Pankreas hormone (FSH) (ii) Merangsang spermatogenesis di lelaki.
Pancreas
Stimulates spermatogenesis in males.

(c) Hormon peluteinan (i) Merangsang ovulasi , perkembangan korpus luteum dan rembesan estrogen dan
progesteron pada wanita.
Luteinising hormone
(LH) Stimulates ovulation , development of corpus luteum and secretion of oestrogen and
progesterone in females.

(ii) Merangsang rembesan testosteron pada lelaki.

Stimulates the secretion of testosteron in males.

(d) Hormon perangsang (i) Merangsang kelenjar tiroid untuk menghasilkan tiroksima .
tiroid
Stimulates the thyroid gland to release thyroxine .
Thyroid stimulating
hormone (TSH)

(e) Hormon (i) Merangsang korteks adrenal untuk menghasilkan hormon.
adrenokortikotrof
Stimulates the adrenal cortex to release hormones.
Adrenocorticotrophic
hormone (ACTH)

(a) Hormon oksitosin (i) Merangsang pengecutan otot uterus semasa kelahiran anak BAB 12
Oxytocin hormone
Stimulates the contraction of the uterine muscles during childbirth

(ii) Merangsang pelepasan susu daripada kelenjar susu

Stimulates the release of milk from the mammary glands

(b) Hormon antidiuresis (i) Merangsang penyerapan semula air daripada tubul ginjal.
Antidiuretic
Stimulates water reabsorption by the renal tubules in the kidneys.
hormone (ADH)
(a) Hormon tiroksina (i) Meningkatkan kadar metabolisme badan.

Thyroxine hormone Increases body metabolic rate.

(a) Hormon insulin (ii) Meningkatkan suhu badan.
Insulin hormone
Increases body temperature .
(b) Hormone glukagon
Glucagon hormone (iii) Mengawal pertumbuhan dan perkembangan.

Regulates growth and development.

(i) Mengurangkan aras glukosa darah dan mengalakkan pertukaran glukosa ke glikogen .

Decreases blood glucose level and promotes the conversion of glucose to glycogen .

(i) Meningkatkan aras glukosa darah dan menggalakkan pertukaran glikogen kepada glukosa.

Increases blood glucose level and promotes the conversion of glycogen to glucose.

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  Biologi  Tingkatan 4  Bab 12 Koordinasi dan Gerak Balas dalam Manusia

(a) Hormon (i) Meningkatkan aras gula dan asid lemak dalam darah.
Adrenalina
Adrenaline hormone Increase the levels of sugar and fatty acids in the blood.

6. Kelenjar adrenal (ii) Meningkatkan aktiviti jantung , kadar dan kedalaman pernafasan.
Adrenal gland
Increase heart activity, the rate and depth of breathing.
7. Ovari
Ovaries (iii) Meningkatkan kadar metabolisme dan mengecutkan saluran darah.
8. Testis
Testes Increase the metabolic rate and constrict some blood vessels.

(b) Hormon aldosteron (i) Meningkatkan penyerapan semula garam mineral di ginjal.
Aldosterone hormone
Increase the reabsorption of mineral salts in the kidneys.

(a) Hormon oestrogen (i) Merangsang perkembangan ciri seks sekunder wanita dan kematangan ovum .
Oestrogen hormone
Stimulates the development of female secondary sexual characteristics and maturation of ova .

(ii) Menggalakkan pembaikan dinding uterus .

Promotes repair of the uterine lining.

(b) Hormon progesteron (i) Merangsang perkembangan dinding uterus dan pembentukan plasenta.
Progesterone hormone
Stimulates development of the uterine lining and formation of the placenta.

(ii) Menghalang ovulasi .

Inhibits ovulation .

(a) Hormon testosteron (i) Merangsang pembangunan ciri-ciri seks sekunder lelaki dan spermatogenesis .
Testosterone hormone
Stimulates the development of male secondary sexual characteristics and spermatogenesis .

Koordinasi Penglibatan Sistem Saraf dan Sistem Endokrin dalam Situasi Cemas

Coordination Involving Both the Nervous System and Endocrine System, in a “fight or flight” Situation

1. Mata mengesan 2. Menghantar impuls saraf 3. Hipotalamus menghantar impuls 4. Medula adrenal merembes
rangsangan ke otak saraf ke medula adrenal hormon adrenalina ke

Eyes detect stimulus Sends nerve impulses to the Hypothalamus sends nerve impulses to dalam darah dan membawa
brain the adrenal medulla
kepada beberapa kesan:

Adrenal medulla

a secretes adrenaline into the
Otak mengesan bahaya dan mengarah
otot kaki untuk melompat. blood, triggering a number of
The brain detects danger and signals the leg
muscles to jump back. effects:

BAB 12 b d
Di hati, glikogen ditukar kepada • Denyutan jantung dan pernafasan bertambah cepat dan kuat.
glukosa dan dibebaskan ke The heartbeats and breathing faster and stronger.
dalam darah.
In the liver, glycogen is converted into • Tekanan darah meningkat.
glucose and released into the blood. Blood pressure rises.

c Medula adrenal
Darah dialihkan dari usus dan ke otot . Adrenal medulla
Blood is diverted away from the intestine
and into the muscles . Perubahan fisiologi Tujuan
Physiological change Reason

Kadar pernafasan Untuk meningkatkan pengambilan oksigen .

meningkat To increase oxygen intake
Increased breathing rate

Denyutan jantung Menghantar lebih banyak darah ke otot,
bertambah terima lebih banyak glukosa dan
Increased heartbeats
oksigen untuk respirasi .
Rangsangan: bahaya
Stimulus: Danger Sending more blood to muscles, so that they
receive more glucose and oxygen for
respiration .

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Biologi  Tingkatan 4  Bab 12 Koordinasi dan Gerak Balas dalam Manusia  

Perbandingan antara Sistem Saraf dengan Sistem Endokrin

Comparison between Nervous System and Endocrine System

Persamaan / Similarities TP 4

• Kedua-dua sistem saraf dan sistem endokrin adalah penting untuk menghantar isyarat ke efektor untuk
menghasilkan gerak balas yang tepat.

Both nervous system and endocrine system are important for transmitting messages to effectors to give proper responses .

Perbezaan / Differences

Jenis koordinasi Sistem saraf Sistem endokrin
Type of coordination Nervous system Endocrine system
(a) Koordinasi hormon
(a) Koordiansi saraf . Hormonal coordination
Nervous coordination.
(b) Kelenjar endokrin , darah
Sistem komponen (b) Neuron , otak , saraf tunjang Endocrine glands, blood
Components of the system Neurones , brain , spinal cord
(c) Kimia (hormon)
Ciri isyarat (c) Electrik (impuls saraf di gentian saraf) Chemical (hormones)
Nature of message Electrical (nerve impulses along nerve fibres)
Kimia ( neurotransmiter merentasi sinaps) (d) Aliran darah
Blood stream
Chemical ( neurotransmitter across synapses)
(e) Perlahan / slow
Laluan penghantaran (d) Gentian saraf
Route of transmission Nerve fibres (f) Lambat untuk bertindak balas
Take longer time to react
Kelajuan penghantaran (e) Sangat cepat
impuls Rapid (g) Luas , hormon mungkin menjejaskan
Speed of transmission beberapa orgen sasaran pada masa yang
sama
Gerak balas (f) Kesan serta merta
Responses Instant effect Widespread , hormone may affect several
target organs at the same time
Kawasan sasaran (g) Terhad pada organ sasaran BAB 12
Areas of response Restricted to target organ (h) Kesan jangka panjang
Usually long-lasting effect
Tempoh kesan (h) Kesan jangka pendek
Duration of effect Short-term effect (i) Pembiakan, pertumbuhan dan
perkembangan
Proses badan yang (i) Tindakan terkawal (berjalan, menulis)
terlibat Voluntary actions (walking, writing) Reproduction, growth and development
Body processes involved (j) Pengawalaturan persekitaran dalaman (luar
(j) Tindakan luar kawal (tindakan refleks)
Involuntary actions(reflex actions) kawal)
Regulation of internal environment (always

involuntary)

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  Biologi  Tingkatan 4  Bab 12 Koordinasi dan Gerak Balas dalam Manusia

12.7 Isu Kesihatan Berkaitan Sistem Endokrin Manusia

Health Issues Related to Human Endocrine System
Kesan ketakseimbangan hormon / The effects of hormonal imbalance

Kekurangan / Under secretion Berlebihan / Over secretion

Kekerdilan / Dwarfism Kegergasian / Gigantism
(a) Pertumbuhan badan yang berlebihan semasa kanak-
(a) Keadaan saiz badan yang lebih kecil seperti
kanak.
kanak-kanak. size of the body is like that of a child. Hormon Ezcessive growth of the entire body during childhood.
The smaller pertumbuhan (b) Individu membesar dengan ketinggian luar biasa
(b) Organ individu itu gagal berkembang dan
pertumbuhan tulang terbantut. Growth disebabkan oleh pemanjangan tulang yang
The organs of the affected person often fail to grow and hormone abnormal.
the bone growth is retarded.
Hormon The affected person grows abnormally tall due to
Hipotiroidisme / Hypothyroidism tiroksina abnormal increase in the length of bones .
(a) Kretinisme pada kanak-kanak: perkembangan fizikal Thyroxine
hormeones Hipertiroidisme / Hyperthyrodism
dan mental yang terbantut. (a) Penyusutan berat badan / Weight loss
Cretinism in children: mental retardation and stunted growth. (b) Keresahan / Nervousness
(b) Pada orang dewasa: metabolisme rendah, kelesuan, (c) Metabolisme tinggi / High metabolism
(d) Kepanasan / Overheating
berat badan berlebihan , dan berasa sejuk.
Diabetes insipidus / Diabetes incipidus
Adults: low metabolism , often fatigued, overweight , (a) Kekurangan ADH .
Lack of ADH
and feel cold. (b) Badan kehilangan banyak air akibat membuang

Diabetes mellitus / Diabetes melitus air kencing yang banyak.
(a) Pankreas tidak menghasilkan insulin .
The pancreas is not producing insulin . The body loses a lot of water where a large amount of
(b) Aras glukosa yang tinggi dalam darah. urine is excreted.
High levels of glucose in the blood.
(c) Glukosa disingkir dalam air kencing .
Glucose presents in the urine .

PRAKTIS SPM 12

BAB 12 Soalan Objektif 2. Rajah 1 menunjukkan sel yang khusus.
1. Alimengalamikecederaankepaladankesukaranbernafas Diagram 1 shows a specialised cell.
2018
selepas menemui kemalangan jalan raya. Nukleus Soma (badan sel)
Ali suffered a head injury and difficulty in breathing after a Nucleus Soma (cell body)

road accident. KBAT Mengaplikasi Selaput mielin Tapak akson
Myelin sheaths Axon terminals

AC Dendrit
Dendrites
D
Akson
B Axon

Antara bahagian berlabel A, B, C dan D, yang manakah Rajah 1/ Diagram 1
mengalami kecederaan?
Apakah sel itu? / What is the cell?
Which of the following part labelled part A, B, C or D was A Neuron deria / Sensory neurone
injured? B Neuron motor / Motor neurone
C Interneuron / Interneurone
D Sel sperma / Sperm cell

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Biologi  Tingkatan 4  Bab 12 Koordinasi dan Gerak Balas dalam Manusia  

Bahagian A

1. Rajah 2 menunjukkan sebahagian daripada sistem endokrin manusia. Kelenjar pituitari
Diagram 2 shows part of the human endocrine system. Pituitary gland
(a) Namakan struktur X dan Y. / Name structure X and Y. Tiroid
Thyroid

X : Kelenjar adrenal / Adrenal gland

Y : Pankreas / Pancreas [2 markah / 2 marks] X Y
Ginjal
Kidney

(b) (i) Nyatakan dua hormon yang dirembeskan oleh Y.
State two hormones secreted by Y.

Hormon 1 / Hormone 1 : Insulin / Insulin

Hormon 2 / Hormone 2 : Glukagon / Glucagon

[2 markah / 2 marks] Rajah 2 / Diagram 2

(ii) Terangkan bagaimana hormon 1 dan hormon 2 di (b)(i) mengawal aras glukosa dalam darah.
Explain how hormone 1 and hormone 2 in (b)(i) regulate the level of glucose in the blood.
Hormon 1 / Hormone 1:

Insulin yang dirembeskan oleh pankreas menukar glukosa berlebihan kepada glikogen dan disimpan di

dalam hati atau tisu otot.

Insulin secreted by pancreas stimulates the conversion of excess glucose into glycogen and store in the liver or muscle cells.

Hormon 2 / Hormone 2:
Glukagon yang dirembeskan oleh pankreas menukar glikogen kepada glukosa di dalam darah.

Glucagon secreted by pancreas stimulates the conversion of glycogen into glucose in the blood.
[2 markah / 2 marks]

(c) Aminah mempunyai penyakit diabetes dan tekanan darah tinggi yang menyebabkan kegagalan kedua-dua ginjalnya
untuk berfungsi. Terangkan kesan kegagalan ginjal terhadap pengawalaturan keseimbangan air dalam darah.

Aminah has diabetes and high blood pressure which cause both of her kidneys fail to function. Explain the effect of the kidney failure
in regulating water balance in the blood. KBAT Mengaplikasi

Kegagalan ginjal menyebabkan pengosmokawalaturan tidak berlaku. / Kidney failure cause osmoregulation not occur. BAB 12

Penyerapan semula air tidak berlaku. / Reabsorption of water cannot occur.

Kandungan air dalam darah rendah. / Low water content in the blood.

Tekanan osmosis darah meningkat. / Increase blood osmotic pressure.

Lebihan air kencing. / More urine is formed.

Menyebabkan ternyahidrat. / Cause dehydrate. [3 markah / 3 marks]


Kuiz 12

179

BAB  Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia

13 Homeostasis dan Sistem Urinari Manusia

Homeostasis and Human Urinary System

PETA Konsep

Homeostasis dan Sistem Urinari Manusia
Homeostasis and Human Urinary System

Homeostasis Sistem Urinari Manusia Isu Kesihatan
Homeostasis Urinary System in Humans Health Issues

Maksud Mekanisme Suap Proses Pengosmokawalaturan
Meaning Balik Negatif Pembentukan Air Osmoregulation
Kepentingan
Negative Feedback Kencing Konsep suap balik
Importance Mechanism Formation of Urine negatif
The concept of
Suhu badan Ultraturasan negative feedback
Body temperature Ultrafiltration mechanism
Arah gula darah Penyerapan semula
Blood sugar level Reabsoprtion
Tekanan separa
karbon dioksida Rembesan
Partial pressure Secreation
carbon dioxide
BAB 13 Tekanan darah Ginjal Berkaitan Sistem
Blood pressure Kidney Urinasi

Struktur Related to the
Structure Urinary System
Fungsi
Function Uretritis
Ureteritis
Pielonefritis
Pielonefritis
Batu karang
Kidney stones

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Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia  

13.1 Homeostasis

Homeostasis

1. Persekitaran luar badan sentiasa berubah. Oleh itu adalah penting untuk manusia mengekalkan kestabilan
persekitaran dalam untuk kemandirian .

The external environment is continually changing. It is important to keep the internal environment of our body stable
for survival of humans.

2. Pengekalan persekitaran dalam yang stabil atau tetap dikenali sebagai homeostasis .

The maintenance of a stable or relatively constant internal environment is known as homeostasis .

Badan manusia Malar
Human body Relatively constant
Sel-sel badan dibasahi dalam bendalir tisu
Persekitaran luar Parameter persekitaran dalam: Body cells bathed in tissue fluid
External environment Parameters of internal environment:
(a) Berubah berterusan (b) Suhu badan / Body temperature
Continually changing (c) Tekanan darah / Blood pressure
air water
(d) Kandungan darah / Blood content
(e) Aras gula darah / Blood sugar level
(f) Tekanan separa oksigen dan karbon dioksida
Partial pressure of oxygen and carbon dioxide

3. Keperluan untuk mengekalkan faktor fizikal dan faktor kimia persekitaran dalam

The necessity to maintain physical and chemical factors in the internal environment

(a) Suhu badan (i) Suhu badan yang stabil adalah penting untuk enzim berfungsi dengan cekap.
Body temperature stable body temperature is essential for enzymes to function properly.
A
(ii) Pada manusia, kulit terlibat dalam mengekalkan suhu badan pada 36.5 – 37°C .
In humans, the skin is involved in keeping the body temperature at 36.5 – 37°C .

Ͻ35°C Ͼ37.5°C
Menggigil Demam Fever
Severe shivering

36 38 40 42
35 37 39 41 °C

36.5-37°C Ͼ41°C BAB 13
Suhu badan normal Pengsan, kekeliruan
Normal body Fainting, confusion
temperature

(b) Kandungan air dalam (i) Kandungan air yang stabil dalam sel adalah penting supaya sel-sel dapat menjalankan aktiviti metabolisme
darah
dengan baik. water content in the cells is important so that cells can carry metabolic activities properly.
Blood water content stable

(ii) Ini dapat mengelakkan kesan osmosis yang boleh merosakkan sel.
This is to avoid osmotic effects that could damage the cells.
(iii) Kandungan air dalam darah dikawal oleh ginjal dalam sistem urinari .
kidneys urinary
The water content in blood is regulated by the of the system.

(c) Tekanan separa (i) Kandungan oksigen dalam darah dikekalkan supaya mempunyai oksigen yang mencukupi untuk respirasi
oksigen dan karbon
dioksida darah sel. oxygen content in blood has to be kept stable to provide sufficient oxygen to cells for respiration .

Partial pressure of oxygen The
and of carbon dioxide in (ii) Kandungan karbon dioksida dalam darah yang tetap untuk mengekalkan pH dalam darah
blood
stabil.
carbon dioxide pH
The content in blood has to be kept constant to maintain a stable in blood.

181

  Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia

(iii) Kandungan gas dalam darah dikawalatur melalui pernafasan dan denyutan jantung dalam sistem respirasi
dan peredaran darah.

The respiratory system and the circulatory system are involved in the regulation of gas content in blood through
breathing and heartbeat .

(iv) pH yang tetap membolehkan aktiviti enzim adalah optimum .
Constant pH levels allows enzyme to function at their optimum activity.

(d) Aras gula darah (i) Aras gula darah perlu stabil untuk membekalkan glukosa yang mencukupi bagi respirasi sel.
Blood sugar level glucose to cells for respiration .
The sugar level in blood has to be kept stable to provide sufficient
(ii) Aras glukosa darah dikawal oleh pankreas dan hati
.
The blood glucose level is regulated by the pancreas and the liver .

Mekanisme Homeostasis

Mechanism of Homeostasis

• Homeostasis dilakukan oleh mekanisme suapbalik negatif .

Homeostasis is usually brought about by negative feedback mechanism.

(a) Reseptor (b) Pusat kawalan (c) Efektor Bergerak balas untuk
Receptors Control centre Effectors mengurangkan aras

Response to decrease the level

Aras parameter lebih tinggi (e) Suapbalik negatif
daripada normal Negative feedback
(f) Suapbalik negatif
Level of parameter higher than Negative feedback
normal
BAB 13
Meningkat
Increases

(d) Aras normal parameter
Normal level of parameter

Menurun
Decreases

Aras parameter lebih rendah
daripada normal

Level of parameter lower than
normal

(g) Reseptor (h) Pusat kawalan (i) Efektor Bergerak balas untuk
Receptors Control centre Effectors meningkatkan aras

Response to increase the level

Pengawalaturan Suhu Badan

The Regulation of Body Temperature

1. Mekanisme yang mengimbangkan jumlah haba dalam badan adalah di bawah kawalan pusat pengawalaturan
suhu di hipotalamus .

In our body, the mechanisms that balance the amount of heat gain and heat loss are under the control of the thermoregulatory
centre in the hypothalamus of the brain.

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Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia  

2. Hipothalamus mempunyai termoreseptor untuk mengesan suhu aliran darah (suhu dalam).

The hypothalamus has thermoreceptors that can detect the temperature of the blood passing through it (i.e. internal
temperature).

3. Ia juga menerima impuls saraf daripada termoreseptor kulit berkaitan perubahan suhu kulit (suhu luar).

It also receives nerve impulses about changes in skin temperature (i.e. external temperature) from the

thermoreceptors in the skin.

Pusat pengawalaturan suhu
Thermoregulatory centre

Suhu darah ↑ Suhu darah ↑ ↑
Blood temperature ↑ Blood temperature

Suhu kulit ↑ Dikesan oleh Suhu kulit ↑ ↑
Skin temperature ↑ Detected by Skin temperature

Dikesan oleh (c) Termoreseptor Dikesan oleh
Directed by di hipotalamus Directed by

Suhu badan (b) Termoreseptor Thermoreceptors (d) Termoreseptor Suhu badan
normal di kulit in hypothalamus di kulit normal

Normal body Thermoreceptors Merangsang Merangsang Thermoreceptors Normal body
temperature in skin Stimulate Stimulate in skin temperature

Pusat haba Pusat haba
Heat loss Heat gain
centre centre

Mekanisme pembetulan Mekanisme pembetulan
Corrective mechanisms Corrective mechanisms
↑
(a) Suapbalik negatif 1. Kehilangan haba ↑ Memulakan Memulakan 1. HKeehatillaonssga↑n haba (e) Suapbalik negatif
Negative feedback Initiate Initiate Negative feedback
Heat loss ↑ ↑
2. HPeeraot lgeahinan↑haba 2. Perolehan haba ↑

Heat gain ↑

Mekanisme Pembetulan

Corrective Mechanisms

Gerak balas untuk meningkatkan kehilangan haba dalam Efektor Gerak balas untuk mengurangkan kehilangan haba BAB 13
keadaan panas Effectors dalam keadaan sejuk
Responses to increase heat loss under hot conditions Responses to reduce heat loss under cold conditions

3 3
2

2

1 Kulit 1

The skin

44

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  Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia

1. Otot regang mengendur dan rambut condong ke Otot regang 1. Otot regang mengecut dan rambut menegak .
Erector muscles contract to pull hairs upright .
permukaan kulit. rambut
Erector muscles relax and hairs lie flat on the skin Hair erector • Satu lapisan udara yang tebal terperangkap dan
penebatan haba adalah baik .
• Satu lapisan udara yang nipis terperangkap dan muscles
penebatan haba adalah rendah . A thick layer of still air is trapped for good insulation of

A thin layer of still air is trapped and heat insulation is heat.
poor .

2. Perpeluhan meningkat . Kelenjar 2. Perpeluhan berkurang atau tidak berlaku.
Sweating increases . peluh Sweating reduces or does not occur.

• Badan kehilangan haba secara penyejatan peluh. Sweat glands • Kurang haba disingkir
Evaporation of sweat removes heat. Less heat is lost

3. Penvasodilatan berlaku di arteriol Arteriol 3. Penvasocerutan berlaku di arteriol.
Vasodilation occurs at the arterioles. Arterioles Vasoconstriction occurs at the arterioles

• Lebih darah mengalir ke kapilari di kulit • Kurang darah mengalir ke kapilari di kulit.
More blood flows to capillaries of skin. Less blood flows to capillaries of skin.

• Haba berlebihan disingkir melalui sinaran . • Kurang haba disingkir melalui sinaran .
More heat is lost by radiation . Less heat is lost by rariation .

4. Lapisan lemak bawah kulit menjadi lebih nipis . Lapisan 4. Lapisan lemak bawah kulit menjadi lebih tebal .
The layer of subcutaneous fat becomes thinner . The layer of subcutaneous fat becomes thicker .
lemak

bawah kulit
Layer of

subcutaneous
fat

5. Otot rangka tidak mengecut dengan cepat dan Otot rangka 5. Otot rangka mengecut dengan cepat dan berulang-
Skeletal
berulang-ulang. muscles ulang,
Skeletal muscles are not contract rapidly and repeatedly. Skeletal muscles contract rapidly and repeatedly.

• Badan tidak menggigil . • Badan menggigil .
Shivering not occurs. Shivering occurs.

BAB 13 • Kadar respirasi sel-sel otot meningkat dan lebih
haba dijana.

The rate of respiration in muscle cells is increased in order
and more heat is generated.

6. Kelenjar adrenal dan kelenjar tiroid kurang dirangsang Kelenjar 6. Kelenjar adrenal dan kelenjar tiroid dirangsang
Adrenal and thyroid glands are less stimulated Adrenal and thyroid glands are stimulated
adrenal &
• Kurang hormon adrenalina dan tiroksina kurang • Lebih hormon adrenalina dan tiroksina dirembes
tiroid More adrenaline and thyroxine are secreted
dirembes. Adrenal
Less adrenaline and thyroxine are secreted. & thyroid • Kadar metabolisme meningkat , banyak haba
glands
• Kadar metabolisme rendah , kurang haba dijana. dijana.
The metabolic rate is low , less heat is generated. The metabolic rate increases , more heat is generated.

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Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia  

Pengawalaturan Aras Gula Darah

The Regulation of Blood Sugar Level

1. Pankreas mengandungi kemoreseptor yang dapat mengesan perubahan aras glukosa darah.

The pancreas contains chemoreceptors that detect changes in blood glucose level.

2. Ia juga adalah kelenjar endokrin yang merembes hormon untuk mengawalatur aras glukosa darah.

It is also an endocrine gland that secretes hormones involved in regulation of blood glucose level.

3. Sel hati dan sel badan adalah efektor dalam pengawalaturan aras glukosa darah.

Liver cells and body cells are effectors in regulation of blood glucose level.

Aras glukosa a b c
darah Sel-sel Islet di Sel hati dan Insulin merangsang
sel badan Insulin stimulates
lebih tinggi pankreas merembes Liver cells and 1. Pengambilan lebih glukosa untuk respirasi sel.
daripada lebih insulin dan body cells More glucose uptake by body cells for cellular respiration .
normal kurang glukagon . 2. Sel hati menukar glukosa berlebihan kepada
Islet cells in pancreas glikogen dan disimpan di dalam hati dan otot .
Blood glucose secretes more insulin Liver cells to convert excess glucose to glycogen , which
level higher and less glucagon . is then stored in the liver and muscles .
than normal 3. Tisu adipos menggunakan glukosa untuk membentuk
lemak .
Adipose tissues use glucose to form fat .

Selepas hidangan
After a meal

Aras glukosa darah normal Suapbalik negatif d
Normal blood glucose level Negative feedback Aras glukosa darah menurun
Suapbalik negatif Blood glucose level decreases
Semasa puasa atau Negative feedback
selepas bersenam e
During fasting or after Aras glukosa darah meningkat
Blood glucose level increases
exercise
BAB 13
Aras glukosa f g h
darah lebih Sel-sel dalam kelompok Sel-sel hati Glukagon merangsang
Sel Langerhans di Liver cells Glucagon stimulates
rendah pankreas merembes (i) Sel hati menukar glikogen simpanan kepada
daripada lebihan glukagon dan glukosa .
normal kurang insulin . Liver cells to convert stored glycogen to glucose .
Blood glucose Langerhans cells in (ii) Tisu adipos mengurai lemak kepada asid lemak
level lower pancreas secretes more yang boleh digunakan untuk menjana tenaga .
than normal glucagon and less insulin . Adipose tissue to breakdown fats which release fatty
acids that can be metabolised to generate energy .

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  Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia

Pengawalaturan Tekanan Separa Karbon Dioksida

The Regulation of Partial Pressure of Carbon Dioxide

1. Pernafasan adalah proses luar kawal yang dikawal atur oleh pusat respirasi di medula oblongata .

Breathing is an involuntary process which is controlled by the respiratory centre located in the medulla oblongata .

2. Pengawalaturan kadar dan kedalaman pernafasan merupakan mekanisme suapbalik negatif .

The control of the rate and depth of breathing works by a negative feedback mechanism.

Semasa senaman cergas
During vigorous exercise

Tekanan separa CoOf C2Od2airnahblomoednriisnegskat Tekanan separa oCfOC2Od2 ainrabhlomodenfaullrsun
Partial pressure Partial pressure

pH darah berkurang pH bendalir serebrospinal pH darah bertambah pH bendalir serebrospinal bertambah
pH of blood decreases berkurang pH of blood increases pH of cerebrospinal fluid increases

Dikesan oleh pH of cerebrospinal fluid decreases Dikesan oleh Dikesan oleh
Detected by Detected by Detected by
Dikesan oleh
Detected by

Kemoreseptor di jasad Kemoreseptor di Kemoreseptor di jasad Kemoreseptor di
aorta dan jasad karotid kemoreseptor pusat aorta dan jasad karotid kemoreseptor pusat
Chemoreceptors in aortic Chemoreceptors in central Chemoreceptors in aortic Chemoreceptors in centrel
bodies and carotid bodies bodies and carotid bodies
chemoreceptors chemoreceptors

Impuls saraf Impuls saraf
Nerve impulses Nerve impulses

Pusat respirasi Pusat respirasi
The respiratory centre The respiratory centre
Impuls saraf
Impuls saraf Nerve impulses
Nerve impulses

BAB 13 Pengecutan otot-otot interkostal dan diafragma Pengecutan otot-otot interkostal dan diafragma
lebih cepat dan kuat . lebih perlahan dan lemah .

Contraction of intercostal muscles and diaphragm is Slower and weaker contraction of intercostal muscles
faster and stronger and diaphragm .
Kesannya
As a result Kesannya
As a result

Kadar dan kedalaman pernafasan bertambah Kadar dan kedalaman pernafasan berkurang
Rate and depth of breathing increase Rate and depth of breathing decrease

Tekanan mseepnauraruCnO2 darah TekananmseenpianrgakCatO. 2 darah

Partial pressure of CO2 in Partial pressure of CO2 in
blood falls blood rises .
NTeokrmanalapnasrteiaplaprraesCsuOre2 darah normal
of CO2 in blood

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Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia  

Pengawalaturan Tekanan Darah

The Regulation of Blood Pressure

1. Tekanan darah adalah daya yang dikenakan pada dinding arteri.

Blood pressure is the force of the blood exerted on the walls of the arteries.

2. Tekanan darah dikawalatur oleh mekanisma suap-balik negatif .

Blood pressure is regulated by a negative feedback mechanism.

Pusat kawalan kardiovaskular di medula Mekanisme pembetulan:
Correction mechanisms:
oblongata menerima impuls
Cardiovascular centre in medulla oblongata Pengecutan otot kardium menjadi
lemah, kadar denyutan jantung
receives impulses menurun .
Weaker cardiac muscle contractions cause
• Baroreseptor di dinding aorta Impuls saraf heartbeat rate decreases .
dan arteri karotid dirangsang. Nerve impulses
Otot licin arteri mengendur ,
Baroreceptors in the aortic arch pemvasodilatan berlaku.
and carotid arteries are stimulated. Rintangan pengaliran darah dalam
salur darah berkurang .
• Impuls saraf dihantar ke pusat The smooth muscles of the arteries
kardiovaskular relax , vasodilation occurs. This reduces
the resistance of blood flow in the blood
Impulses are sent to the vessels.
cardiovascular centre.

Semasa senaman fizikal
During physical activities

Tekanan darah meningkat Pemvasodilatan
Blood pressure increases Vasodilation

(Ͼ120/80 mmHg)

Tekanan darah normal
Normal blood pressure

Mekanisme pembetulan: Tekanan darah menurun Semasa dalam keadaan terkejut
Correction mechanisms: Blood pressure decreases When in a state of shock

Pengecutan otot kardium lebih kuat, (Ͻ120/80 mmHg)
kadar denyutan jantung meningkat .
Stronger cardiac muscle contractions cause • Baroreseptor di dinding aorta BAB 13
heartbeat rate increases . dan arteri karotid kurang
dirangsang.
Otot licin arteri mengecut , pemvasocerutan
berlaku. Rintangan pengaliran darah dalam Baroreceptors in the aortic arch and
salur darah bertambah . carotid arteries are less stimulated.
The smooth muscles of the arteries contract ,
vasoconstriction occurs. This increases the resistance • Kurang impuls saraf dihantar ke
of blood flow in the blood vessels. pusat kardiovaskular

Impuls saraf dihantar ke efektor Fewer impulses are sent to the
melalui saraf simpatetik . cardiovascular centre.
Nerve impulses are sent to the effectors
via sympathetic nerves. Impuls saraf
Nerve impulses

Pusat kawalan kardiovaskular di
medula oblogata menerima impuls.
Cardiovascular centre in medulla
oblongata receives impulses.

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  Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia

13.2 Sistem Urinari

The urinary system

Struktur dan Fungsi Ginjal Manusia

Structure and Functions of Human Kidney

1. Ginjal adalah organ perkumuhan dan pengosmokawalaturan .

The kidneys are the organ of excretion and osmoregulation .

2. Nefron adalah unit berfungsi ginjal.

Nephrons are the functional units of the kidney.

Nefron / Nephron

Ginjal Korteks
Kidney Cortex

Arteri renal Medula
Renal artery Medulla

Vena renal Pelvis
Renal vein Pelvis

Sistem Urinari manusia Ureter Tubul pengumpul
The human urinary system Ureter Collecting duct

3. Nefron terdiri daripada glomerulus , kapsul Bowman dan tubul renal yang panjang. Tubul dibahagikan

kepada beberapa bahagian.

A nephron is made up of a glomerulus , a Bowman’s capsule and a long renal tubule . The tubule can be divided into
several sections.

(a) Tubul berlingkar di korteks membentuk tubul berlingkar proksimal .

The tubule coils up in the cortex to form the proximal convoluted tubule.

(b) Tubul memanjang ke medula untuk membentuk liku Henle yang berbentuk U.

It then extends into the medulla to form the U-shaped loop of Henle .

(c) Tubul masuk dan berlingkar semula di korteks membentuk tubul berlingkat distal .

It returns to the cortex and coils up again to form the distal convoluted tubule.

4. Tubul berlingkar distal akan membawa kepada duktus pengumpul .

The distal convoluted tubule finally leads to the collecting duct .

BAB 13 Glomerulus Kapsul Bowman
Glomerulus Bowman’s capsule

Arteriol eferen Tubul berlingkar proksimal
Efferent arteriole Proximal convoluted tubule

Arteriol aferen Tubul berlingkar distal
Afferent arteriole Distal convoluted tubule

Arteri renal Duktus pengumpul
Renal artery Collecting duct

Vena renal Liku Henle
Renal vein Loop of Henle

Kapilari darah
Blood capillary

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Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia  

Pembentukan Air Kencing

Formation of Urine

1. Proses utama yang terlibat dalam pembentukan air kencing:

The main processes involved in urine formation:

(a) Ultraturasan / Ultrafiltration
(b) Penyerapan semula / Reabsorption
(c) Rembesan / Secretion

A Ultraturasan

Ultrafiltration

(a) Apabila darah sampai glomerulus, tekanan hidrostatik darah adalah tinggi secara bandingan.

When the blood reaches the glomerulus, it is under a relatively high hydrostatic pressure.

(b) Tekanan dikekalkan dan dipertingkatkan kerana arteriole aferen yang mempunyai diameter yang lebih
besar berbanding arteriole eferen .

The pressure is maintained and enhanced because the afferent arteriole has a larger diameter than the efferent arteriole.

(c) Tekanan darah yang tinggi memaksa air dan molekul terlarut (glukosa, asid amino, garam dan urea)
dalam plasma terturas melalui dinding nipis glomerulus dan kapsul Bowman ke dalam ruang kapsul.

The high blood pressure forces water and small soluble molecules (e.g. glucose, amino acids, salts and urea) in the
plasma through the thin walls of the glomerulus and the Bowman’s capsule into the capsular space.

(d) Proses ini adalah pasif dikenali sebagai ultraturasan .

This is a passive process called ultrafiltration .

Aliran darah masuk Aliran darah keluar
Blood flow in Blood flow out

Arteriol eferen
Efferent arteriole

Arteriol aferen Kapsul Bowman
Afferent arteriole Bowman’s capsule

Glomerulus Ruang kapsul (dengan
Glomerulus hasil turasan glomerulus)
Capsular space (with
Air Urea glomerular filtrate)
Water Urea

Glukosa Garam BAB 13
Glucose Asid amino Salts
Amino acid

Ke tubul berlingkar proksimal
To proximal convoluted tubule

(e) Hasil turasan glomerulus mempunyai komposisi yang sama dengan plasma tetapi tidak mengandungi

protein plasma dan eritrosit .

The glomerular filtrate has a similar composition to plasma but does not contain plasma proteins and

erythrocytes .

(f) Protein plasma dan eritrosit adalah terlalu besar untuk merentasi membran penurasan di glomerulus

dan kapsul Bowman.

Plasma proteins and erythrocytes are too large to pass through the filtration membrane of the glomerulus and the
Bowman’s capsule.

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  Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia

B Penyerapan semula

Reabsorption

(a) Selepas ultraturasan, hasil turasan glomerulus mengalir melalui tubul renal.

After ultrafiltration, the glomerular filtrate flows through the renal tubule .

(b) Penyerapan semula berlaku apabila bahan yang berguna (glukosa dan asid amino) dan kebanyakan
air dalam hasil turasan diserap semula ke dalam kapilari sepanjang tubul.

Reabsorption takes place when useful substances (e.g. glucose and amino acids) and most of the water in the
filtrate are reabsorbed into the surrounding capillaries.

Tubul berlingkar Tubul berlingkar Ke vena renal
proksimal distal To renal vein
Proximal
Distal convoluted
convoluted tubule tubule

Glomerulus
Glomerulus

Dari arteri renal Kapilari Duktus pengumpul
From renal artery Capillary Collecting duct

Kapsul Bowman
Bowman’s capsule

Liku Henle
Loop of Henle

Bahan & % penyerapan Bahagian tubul renal melakukan penyerapan semula
semula Part of the kidney tubule where reabsorption occurs

Substance & % reabsorbed Proses Tubul berlingkar Liku Henle Tubul berlingkar Duktus
Process Loop of
proksimal Henle distal pengumpul
Proximal Distal convoluted Collecting
convoluted tubule
tubule duct

Glukosa / Glucose • Resapan / Diffusion ✓
(100%) • Pengangkutan aktif
Active transport

Asid amino / Amino acid • Resapan / Diffusion ✓
(100%) • Pengangkutan aktif / Active

BAB 13 transport

Garam (Na+, Cl–) • Resapan
Diffusion
Salt (Na+, Cl–) • Pengangkutan aktif / Active ✓ ✓ ✓ ✓
(80%)
transport

Air / Water • Osmosis ✓✓ ✓ ✓
(99%)

Urea / Urea • Resapan / Diffusion ✓✓ ✓ ✓
(50%)

(c) Selepas penyerapan semula, hasil turasan yang tertinggal dalam duktus pengumpul adalah air kencing .

After reabsorption, the remaining filtrate in the collecting duct is called urine .

(d) Air kencing mengandungi kebanyakan air, garam, urea dan bahan kumuh lain.

Urine contains mostly water with salts, urea and other metabolic waste.

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Biologi  Tingkatan 4  Bab 13 Homeostasis dan Sistem Urinari Manusia  

C Rembesan

Secretion

(a) Rembesan adalah proses bahan kumuh (urea, asid urik dan ammonia) dirembes keluar daripada darah
ke dalam tubul renal.

Secretion is the process where waste substances (urea, uric acid and ammonia) are secreted from the blood capillaries
into the renal tubule.

(b) Rembesan berlaku terutamanya di tubul berlingkar distal secara resapan pasif dan pengangkutan aktif .

Secretion takes place especially at the distal convoluted tubule by passive diffusion and active transport.

D Pengosmokawalaturan

Osmoregulation

(a) Pengosmokawalaturan adalah proses mengawal kandungan air dan kepekatan garam dalam badan

pada julat normal.

Osmoregulation is the control of the water content and salt concentration in the body at a constant level.

(b) Proses ini dicapai dengan mengawal jumlah air diserap semula daripada turasan glomerulus di tubul
ginjal melalui mekanisme suap-balik negatif .

This process is achieved by regulating the amount of water reabsorbed from the glomerular filtrate in the kidney
tubules through a negative feedback mechanism.

(c) Penyerapan semula air di tubul ginjal dikawal oleh hormon antidiuresis (ADH) yang dibebaskan daripada
kelenjar pituitari .

The amount of water reabsorbed in the kidney tubules is controlled by the antidiuretic hormone (ADH) released from
the pituitary gland.

Dikesan oleh osmoreseptor Kelenjar pituitari Dinding tubul berlingkar Lebih air diserap semula ke
di hipotalamus . merembes lebih distal dan duktus dalam darah, air kencing
yang sedikit dan lebih pekat
Detected by osmoreceptors in ADH . pengumpul menjadi lebih
hypothalamus . The pituitary gland telap terhadap air. terhasil.
releases more ADH . More water reabsorbed into
Tekanan osmosis darah lebih Wall of distal convoluted blood, a smaller volume of
tinggi dari normal. tubule and collecting duct concentrated urine formed.
becomes more permeable
Blood osmotic pressure higher Tekanan osmosis darah
than normal. to water. menurun .

• Minum kurang air Suapbalik negatif Blood osmotic pressure falls . BAB 13
Drinking too little water Negative feedback
• Perpeluhan berlebihan. Suapbalik negatif Tekanan osmosis darah
Heavy sweating. Negative feedback meningkat .

Tekanan osmosis darah normal Kelenjar pituitari Dinding tubul berlingkar Blood osmotic pressure rises .
Normal blood osmotic pressure merembes kurang distal dan duktus
kurang air diserap semula ke
• Minum lebih air ADH . pengumpul menjadi dalam darah, air kencing yang
Drinking too much water. The anterior pituitary kurang telap terhadap banyak dan lebih cair
• Kurang pengambilan garam
Less salt intake gland releases less air. terhasil.
Tekanan osmosis darah lebih ADH . Wall of distal convoluted Less water reabsorbed into blood
rendah daripada normal. tubule and collecting duct and a larger volume of dilute
Blood osmotic pressure lower becomes less permeable to
urine formed.
than normal. water.

Dikesan oleh osmoreseptor
di hipotalamus .

Detected by osmoreceptors in
hypothalamus .

191