8.1 MAMMALIAN HEART AND ITS REGULATION a) Explain the mechanism of heartbeat(C3) b) Explain the sequence of cardiac cycle (including changes in pressure and volume) (C3) c) Explain ECG waves and complexes in relation with cardiac cycle(C3) d) Explain the regulation of heartbeat in relation to blood pH(C3) BIOLOGY 2 SB025 SEMESTER 2 SESSION 2022/2023 CHAPTER 8: TRANSPORT SYSTEM
CHAPTER 8: TRANSPORT SYSTEM 8.2 : HUMAN LYMPHATIC SYSTEM 1 BIOLOGY 2 SB025 SEMESTER 2 SESSION 2022/2023 CHAPTER 8: TRANSPORT SYSTEM
LEARNING OUTCOMES: a)Describe the pathway of lymph from tissues to blood circulatory system. b)Describe the transport of lipids from small intestine into the blood circulatory system 3 8.2 : HUMAN LYMPHATIC SYSTEM
⮚ Lymphatic system is a system of lymphatic capillaries and vessels separate from the circulatory system that return the interstitial fluid to the blood. ⮚ Excess interstitial fluid is returned in the form of lymph. It is important to maintain blood volume and avoid edema. 4 LYMPHATIC SYSTEM ⮚ Contains a network of vessels ⮚ That transport lymphatic fluid @ lymph ⮚ from the interstitial fluids into the blood stream
5 Flow for the formation and return of lymphatic fluid:
LYMPHATIC SYSTEM: COMPONENTS 6
❖ Consist mostly of water with dissolved salts, many lymphocytes and fats 7 LYMPH @ LYMPHATIC FLUID
❖ Most of the interstitial fluid returns to blood capillaries while the remaining enters lymphatic capillaries to become lymphatic fluid @ lymph 8 LYMPH @ LYMPHATIC FLUID
9 ‘dead-end’ tubes ‘flap’ valves LYMPHATIC CAPILLARIES
❖ Lymphatic capillaries are joined together to form lymphatic vessels ❖ Resemble veins but, unlike veins it has thinner walls ❖ Contain more valves ⮚ To prevent the backflow of lymphatic fluid LYMPHATIC VESSELS 10
Blood capillary 11
⮚Thoracic duct: ***Both right and left subclavian veins are part of blood circulatory system LYMPHATIC DUCTS
LYMPHATIC DUCTS 13
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❖ Mostly at neck, armpit ❖ Contain large numbers of white blood cells i) Lymphocytes produce antibodies to destroy pathogens / to neutralise toxins. ii) Macrophage engulf and digest bacteria / foreign particles by phagocytosis. ❖ Filter out and destroy any infectious or toxic materials ⮚ To prevent foreign particles or bacteria from entering the bloodstream and causing infection LYMPH NODES 15
UNFILTERED LYMPH FILTERED LYMPH UNFILTER ED LYMPH UNFILTER ED LYMPH UNFILTER ED LYMPH Masses of lymphocytes and macrophages Masses of lymphocytes and macrophages LYMPH NODES 19
ENLARGED LYMPH NODES 20
Primary lymphatic organs Secondary lymphatic organs LYMPHATIC ORGANS Structures in which leukocytes develop. Important in the body’s defense system
Blood capillaries Interstitial fluid between cells Lymphatic capillaries Lymphatic vessels Lymphatic nodes Lymphatic ducts Blood veins PATHWAY OF LYMPH @ LYMPHATIC FLUID 19
PATHWAY OF LYMPH @ LYMPHATIC FLUID 20
21 ❖ Most of the interstitial fluid returns to blood capillaries while the remaining enters lymphatic capillaries to become lymphatic fluid @ lymph ❖ From lymphatic capillaries, lymphatic fluid flows in one direction into lymphatic vessels ❖ Valves in lymphatic vessels prevent the backflow of lymphatic fluid into lymphatic capillaries PATHWAY OF LYMPH @ LYMPHATIC FLUID
PATHWAY OF LYMPH @ LYMPHATIC FLUID 22
23 ❖ At certain locations, lymphatic fluid from lymphatic vessels enter the lymphatic nodes ❖ In lymphatic nodes, lymphatic fluid is filtered PATHWAY OF LYMPH @ LYMPHATIC FLUID ❖ The filtered lymphatic fluid flows into lymphatic vessels that conduct it away from lymphatic nodes
24 ❖ Lymphatic fluid in lymphatic vessels from left side of body, alimentary canal and right side of lower part of body flows into thoracic duct ❖ Lymphatic fluid in lymphatic vessels from right side of head and chest flows into right lymphatic duct ❖ From thoracic duct, lymphatic fluid return to blood stream by flowing into left subclavian vein to become blood plasma ❖ From right lymphatic duct, lymphatic fluid return to blood stream by flowing into right subclavian vein to become blood plasma PATHWAY OF LYMPH @ LYMPHATIC FLUID
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Blood capillary Lymph node PATHWAY OF LYMPHATIC FLUID 2 Interstitial fluid between cells 1 3 4 5 Lymphatic ducts Blood vessel s 6 7 P (Intercellular spaces) Lymph node 26
IMPORTANCE OF LYMPHATIC SYSTEM 27 1) Maintain of body fluid balance ❖ Lymphatic vessels transport lymphatic fluid back to the blood circulatory system
2) Defend the body against infection ❖ Defend the body against infection ❖ as macrophages and lymphocytes inside the lymphatic nodes attack and destroy pathogens, bacteria or foreign particles 28 IMPORTANCE OF LYMPHATIC SYSTEM
3) Transportation of lipid via lacteal ❖ Lacteal (lymphatic capillary in villi of small intestine) involve in transportation of lipids 29 IMPORTANCE OF LYMPHATIC SYSTEM
LACTEAL (Lymphatic capillaries) 30
VILLUS & MICROVILLUS 31
TRANSPORTATION OF LIPID FROM SMALL INTESTINE INTO THE BLOOD CIRCULATORY SYSTEM 32
❖ Monoglyceride and fatty acid diffuse into the epithelial cells of small intestine and reformed into triglyceride ❖ Triglyceride is coated with phospholipid, cholesterol and protein forming chylomicron (water soluble globule) ❖ Chylomicron are transported from epithelial cells into lacteal by exocytosis TRANSPORTATION OF LIPID FROM SMALL INTESTINE INTO THE BLOOD CIRCULATORY SYSTEM 33
The formation of chylomicron 34
❖ Lacteal is lymphatic vessel in the villi of small intestine ❖ Lymphatic fluid @ lymph containing chylomicron is known as chyle ❖ Chyle is transported into lymphatic vessel (lacteal) ❖ The backflow is prevented by valves in lymphatic vessels TRANSPORTATION OF LIPID FROM SMALL INTESTINE INTO THE BLOOD CIRCULATORY SYSTEM 35
❖ From lymphatic vessels, chyle is transported through lymphatic nodes and lymphatic ducts ❖ From thoracic duct, chyle enter the blood circulatory system through left subclavian veins ❖ Starting at the lacteals, lymph containing the chylomicrons passes into the large veins that return to the blood to the heart TRANSPORTATION OF LIPID FROM SMALL INTESTINE INTO THE BLOOD CIRCULATORY SYSTEM 43
TRANSPORTATION OF LIPID lipase phospholipid, cholesterol and protein *exocytosis @ lymphatic vessel Chylomicron + lymph = chyle lymphatic nodes lymphatic ducts subclavian veins 37
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THANK YOU! 39 Move your lymph system. Lymph is like a sewage system that carries all of the toxins out of your body. ~Valentina Zelyaeva~