STRUCTURE OF EXCRETORY ORGAN (SKIN) The skin is the largest organ of the body. It has three main layers, the epidermis, the dermis and the subcutaneous layer. FUNCTIONS OF SKIN Provides a protective barrier against mechanical, thermal and physical injury and hazardous substances. Prevents loss of moisture. Reduces harmful effects of UV radiation. Acts as a sensory organ (touch, detects temperature). Helps regulate temperature. An immune organ to detect infections etc. Production of vitamin D. 46
Reabsorption is the movement of water and solutes from the tubule back into the plasma. Reabsorption of water and specific solutes occurs to varying degrees over the entire length of the renal tubule. Bulk reabsorption, which is not under hormonal control, occurs largely in the proximal tubule. Over 70% the filtrate is reabsorbed here. In addition, many important solutes (glucose, amino acids, bicarbonate) are actively transported out of the proximal tubule such that their concentrations are normally extremely low in the remaining fluid. Further bulk reabsorption of sodium occurs in the loop of Henle. Filtration is the mass movement of water and solutes from plasma to the renal tubule that occurs in the renal corpuscle. About 20% of the plasma volume passing through the glomerulus at any given time is filtered. This means that about 180 liters of fluid are filtered by the kidneys every day. Thus, the entire plasma volume (about 3 liters) is filtered 60 times a day! Filtration is primarily driven by hydraulic pressure (blood pressure) in the capillaries of the glomerulus. 1.Filtration 2.Reabsorption Excretion is what goes into the urine, the end result of the above three processes. Although the original concentration of a substance in the tubule fluid may initially be close to that of plasma, subsequent reabsorption and/or secretion can dramatically alter the final concentration in the urine. 3. Regulated reabsorption 4.Secretion Excretory process of kidney Regulated reabsorption, in which hormones control the rate of transport of sodium and water depending on systemic conditions, takes place in the distal tubule and collecting duct. Even after filtration has occured, the tubules continue to secrete additional substances into the tubular fluid. This enhances the kidney's ability to eliminate certain wastes and toxins. It is also essential to regulation of plasma potassium concentrations and pH. 5.Excretion 47
EVAPORATION Excretory process of skin SWEAT GLAND Sweat is produced in response to various stimuli, including heat, exercise, stress, and hormonal changes. SWEAT PRODUCTION EXCRETION OF WASTE PRODUCTS ✦ The primary purpose of sweating is to regulate body temperature by dissipating excess heat. However, it also plays a role in excretion by carrying waste products out of the body. As sweat is produced, it carries waste products, such as urea, ammonia, and metabolic byproducts, from the bloodstream to the surface of the skin. These waste products are then released onto the skin's surface. ✦ Once sweat reaches the skin's surface, it evaporates due to the surrounding air's temperature and humidity. The process of evaporation cools the body and eliminates the waste products carried by the sweat. THE SKIN CONTAINS SWEAT GLANDS, WHICH ARE OF TWO TYPES: ECCRINE SWEAT GLANDS AND APOCRINE SWEAT GLANDS. Eccrine Sweat Glands: These are the most numerous and widely distributed sweat glands in the body. They are responsible for producing sweat. Apocrine Sweat Glands: These are found primarily in the armpits, groin, and around the nipples. Apocrine sweat is thicker and contains proteins and lipid. REGULATION OF ELECTROLYTES Sweat also helps regulate the balance of electrolytes (sodium, potassium, calcium, magnesium, etc.) in the body. The concentrations of these electrolytes in sweat can vary depending on an individual's diet, hydration status, and overall health. ✦ ✦ 48
IMPORTANCE OF EXCRETORY SYSTEM 1. REMOVAL OF WASTE PRODUCTS The primary function of the excretory system is to eliminate metabolic waste products produced by the body's cells. These waste products include urea, creatinine, excess salts, and other harmful substances. Urea is a byproduct of protein metabolism. When our body breaks down proteins for energy or to build and repair tissues, one of the byproducts is ammonia. Ammonia is highly toxic to our cells, so the liver converts it into urea through the ornithine cycle, which is much less harmful. Urea is then transported through the bloodstream to the kidneys. 2. WATER BALANCE (OSMOREGULATION) 3. DETOXIFICATION The liver plays a major role in detoxifying the blood by metabolizing and neutralizing toxins and drugs. For example, the urea(ornithine) cycle plays an important role because it converts the ammonia to urea. The excretory system helps regulate the amount of water in the body. This is crucial for maintaining proper hydration levels, affecting various bodily functions. For filtration and reabsorption in the kidneys, blood is filtered to remove waste products, but crucially, not all water is excreted as urine. Instead, the kidneys selectively reabsorb water, essential substances like electrolytes (sodium, potassium, etc.), and glucose back into the bloodstream. 49
Uremia Uremia is a dangerous condition that occurs when waste products associated with decreased kidney function build up in your blood. Uremia means “urine in the blood” and refers to the effects of waste product accumulation. Uremia most often occurs due to chronic kidney disease (CKD) that may lead to endstage renal (kidney) disease (ESKD). Uremia may cause serious health complications such as fluid accumulation, electrolyte, hormone and metabolic problems. Left untreated, uremia is usually fatal and was always so before dialysis and transplantation were available. Creatinine (waste product produced in muscle and in dietary protein). Urea (waste product formed in the liver as protein is broken down). Estimation of overall kidney function using a formula ( eGFR - ml/min). Stage of CKD from 1 to 5 based on eGFR data from the National Kidney Foundation with dialysis usually starting at Stage 5. Healthy kidneys filter waste and fluids from your body through the urine. Kidneys help maintain normal levels of acids, electrolytes and hormones such as Vitamin D and erythropoietin (EPO). Damaged kidneys don’t work well, allowing multiple toxins to build up in your blood. Most people feel sick when kidney function is less than 15% (15 ml/min) of normal and need to start dialysis when function is less than 10% (10 ml/min) of normal.Lab studies monitor chemicals that are elevated in uremia but not necessarily causative: CAUSES OF UREMIA 50
SYMPTOMS OF UREMIA INCLUDE: Cognitive dysfunction (problems with thinking and remembering). Fatigue. Shortness of breath from fluid accumulation. Loss of appetite. Muscle cramps. Nausea and vomiting. Itching. Unexplained weight loss. In very severe instances, symptoms may include uremic fetor (a urine-like odour on the breath or metallic taste in the mouth) and uremic frost (yellowwhite crystals on the skin due to urea in sweat). 51
Dialysis (a procedure to clean the blood) is the most common treatment for uremia. There are two kinds of dialysis. 1. Hemodialysis uses a machine to filter blood outside the body. 2. Peritoneal dialysis uses the lining of your belly and a special fluid to filter blood. You may need a kidney transplant if uremia is the result of end-stage renal (kidney) failure. A transplant replaces the failing kidney with a donor kidney from either a living or deceased donor. TREATMENT OF UREMIA Your healthcare provider may recommend iron supplementation for anemia, replacement of EPO, calcium and Vitamin D supplements, phosphorus binders taken with meals to prevent bone loss due to hyperparathyroidism. Blood pressure needs to be controlled and any risks for heart disease need to be addressed. Other underlying medical problems must also be managed. 52
STRUCTURE FOR KIDNEY THE KIDNEYS ARE TWO BEAN-SHAPED ORGANS THAT ARE ROUGHLY THE SIZE OF A FIST. A TOUGH, FIBROUS RENAL CAPSULE SURROUNDS EACH KIDNEY AND PROVIDES SUPPORT FOR THE SOFT TISSUE INSIDE. BEYOND THAT, TWO LAYERS OF FAT SERVE AS FURTHER PROTECTION. THE ADRENAL GLANDS LIE ON TOP OF THE KIDNEYS. INSIDE THE KIDNEYS ARE A NUMBER OF PYRAMID-SHAPED LOBES. EACH CONSISTS OF AN OUTER RENAL CORTEX AND AN INNER RENAL MEDULLA. NEPHRONS FLOW BETWEEN THESE SECTIONS. EACH NEPHRON INCLUDES A FILTER, CALLED THE GLOMERULUS, AND A TUBULE. THE GLOMERULUS FILTERS BLOOD, WHICH ENTERS THE KIDNEYS THROUGH THE RENAL ARTERIES AND LEAVES THROUGH THE RENAL VEINS. STRUCTURE 53
FUNCTION OF KIDNEY MAINTAINING OVERALL FLUID BALANCE REGULATING AND FILTERING MINERALS FROM BLOOD FILTERING WASTE MATERIALS FROM FOOD, MEDICATIONS, AND TOXIC SUBSTANCES CREATING HORMONES THAT HELP PRODUCE RED BLOOD CELLS, PROMOTE BONE HEALTH, AND REGULATE BLOOD PRESSURE REMOVING VARIOUS WASTE PRODUCTS SUCH AS UREA, WHICH RESULTS FROM THE BREAKDOWN OF PROTEINS, REABSORBING NUTRIENTS FROM THE BLOOD USING TUBULES SUCH AS GLUCOSE, AMINO ACIDS, WATER AND SODIUM IONS URIC ACID FROM THE BREAKDOWN OF NUCLEIC ACIDS, DRUGS AND THEIR METABOLITES 54
EXCRETORY PROCESS FOR SKIN ULTRAFILTRATION BEGINS IN THE NEPHRON IN THE KIDNEY. BLOOD TRAVELS THROUGH A COILED STRUCTURE OF CAPILLARIES CALLED THE GLOMERULUS SURROUNDED BY THE BOWMAN'S CAPSULE. THE HYDROSTATIC PRESSURE OF THE FLOW OF BLOOD ALLOWS SMALL MOLECULES WITHIN THE BLOOD TO PASS THROUGH THE CAPILLARY MEMBRANE AND THROUGH THE GAPS IN THE PODOCYTES SURROUNDING THE BOWMAN'S CAPSULE. 1.ULTRAFILTRATION 2.REABSORPTION(AT PROXIMAL CONVOLUTED TUBULES ) THE PROXIMAL TUBULES REABSORB ABOUT 65% OF WATER, SODIUM, POTASSIUM AND CHLORIDE AND 85-90% OF BICARBONATE. THE REABSORPTION OF 100% GLUCOSE AND AMINO ACIDS OCCURS THROUGH ACTIVE TRANSPORT .SODIUM IONS ARE ACTIVELY PUMPED INTO THE BLOOD CAPILLARY NETWORK AND CHLORIDE IONS ARE PASSIVELY ABSORBED. IN THE LOOP OF HENLE,WATER IS REABSORBED THROUGH OSMOSIS. SODIUM IONS ARE REABSORBED THROUGH ACTIVE TRANSPORT IN DISTAL CONVOLUTED TUBULES. IN DISTAL CONVOLUTED TUBULES, MORE WATER AND SODIUM IONS ARE REABSORBED. 4.SECRETION AND URINE FORMATION SECRETION OCCURS ALONG THE RENAL TUBULE BUT IS MOST ACTIVE AT THE DISTAL CONVOLUTED TUBULE. SECRETION OCCURS THROUGH SIMPLE DIFFUSION AND ACTIVE TRANSPORT. SUBSTANCES THAT ARE SECRETED INCLUDE HYDROGEN IONS, H+, AND POTASSIUM IONS, K+. WHEN THE RENAL FLUID REACHES THE COLLECTING DUCT, ONLY A SMALL AMOUNT OF SALT IS LEFT. MOST WATER IS ABSORBED BACK INTO THE BLOODSTREAM. THE REMAINING RENAL FLUID NOW CALLED URINE, FLOWS DOWN THE COLLECTING DUCT. AFTER LEAVING THE COLLECTING DUCT, URINE FLOWS THROUGH THE URETER, BLADDER, AND URETHRA AND IS FINALLY EXCRETED 3.REABSORPTION AT LOOP OF HENLE AND DISTAL CONVOLUTED TUBULE 55
Structure Function Epidermis Protects the internal organs, muscles, nerves, and blood vessels from injury Prevents most bacteria, viruses, and other foreign substances from entering the body. Dermis Supporting your epidermis Feeling different sensations such as pressure, pain, heat and cold Producing sweat to control body temperature Hypodermis Helps insulate our body from the cold Act as a cushion for the body internal structures such as muscles and organs when something hits the body STRUCTURE FOR SKIN 56
EXCRETORY PROCESS FOR SKIN SWEAT GLANDS ARE EXOCRINE GLANDS DISTRIBUTED THROUGHOUT THE BODY SURFACE. SWEAT GLANDS IN THE SKIN ALSO PLAY ACTIVE ROLES IN THE EXCRETORY SYSTEM, OR THE ORGANS AND GLANDS THAT FLUSH OUT TOXINS AND EXCESS MINERALS FROM THE BODY. THE ECCRINE GLANDS ARE SIMPLE COILED GLANDS WHOSE MAIN FUNCTION IS TO HELP IN REGULATING THE TEMPERATURE OF THE BODY. THEY SECRETE HYPOTONIC SOLUTION, THE SWEAT, WHOSE EVAPORATION HELPS COOLING THE BODY. IN THE PROCESS OF PRODUCING THE SWEAT, THE ECCRINE GLANDS REABSORB A CERTAIN AMOUNT OF SODIUM AND WATER, WHICH IS WHY THE SWEAT IS HYPOTONIC. WITH SWEAT, WE EXCRETE AMMONIA, UREA, URIC ACID AND SODIUM CHLORIDE. THE PRODUCTION OF SWEAT GLANDS IN YOUR SKIN PRODUCE SWEAT. THERE ARE TWO TYPES OF SWEAT GLANDS: ECCRINE GLANDS ARE FOUND ALL OVER THE BODY AND SECRETE A WATERY PRODUCT THAT COOLS THE SKIN. APOCRINE SWEAT GLANDS ARE MAINLY FOUND IN THE ARMPITS AND PERIANAL AREA AND SECRETE A MORE VISCOUS, ODOROUS PRODUCT. 57
important of the excretory system and health FILTRATION AND BLOOD PURIFICATION THE KIDNEYS ARE ARGUABLY THE MOST VITAL COMPONENTS OF THE EXCRETORY SYSTEM. THESE BEAN-SHAPED ORGANS FILTER APPROXIMATELY 120-150 QUARTS OF BLOOD DAILY, REMOVING WASTE PRODUCTS AND EXCESS SUBSTANCES, SUCH AS UREA, CREATININE, AND ELECTROLYTES. MAINTAINING THE PROPER COMPOSITION OF THE BLOOD IS CRUCIAL FOR OPTIMAL HEALTH AND METABOLIC FUNCTION. REGULATION OF FLUID AND ELECTROLYTE BALANCE ANOTHER KEY FUNCTION OF THE KIDNEYS IS THE REGULATION OF FLUID AND ELECTROLYTE BALANCE. THEY CONTROL THE VOLUME AND COMPOSITION OF BODILY FLUIDS, ENSURING THAT THE CONCENTRATIONS OF SODIUM, POTASSIUM, CALCIUM, AND OTHER ELECTROLYTES REMAIN WITHIN NARROW LIMITS. IMBALANCES CAN LEAD TO SERIOUS HEALTH ISSUES, INCLUDING HYPERTENSION AND CARDIAC ARRHYTHMIAS. HEPATIC DETOXIFICATION HEPATIC DETOXIFICATION INVOLVES A COMPLEX SERIES OF ENZYMATIC REACTIONS IN TWO MAIN PHASES—PHASE I AND PHASE II DETOXIFICATION PATHWAYS. PHASE I REACTIONS MODIFY TOXINS, MAKING THEM MORE AMENABLE TO PHASE II REACTIONS, WHERE THEY ARE CONJUGATED (COMBINED WITH OTHER MOLECULES) TO BECOME WATER-SOLUBLE FOR EASIER ELIMINATION 58
Kidney stones HARD DEPOSITS OF MINERALS AND SALTS THAT FORM IN THE URINARY TRACT AND CAN CAUSE PAIN, INFECTION, OBSTRUCTION AND KIDNEY DAMAGE IF NOT TREATED PROPERLY ACCORDING TO THE HEALTH MINISTER KHAIRY JAMALUDDIN, THERE WERE OVER 40,000 KIDNEY PATIENTS IN MALAYSIA, WITH OVER 8,000 NEW PATIENTS DIAGNOSED ANNUALLY SINCE 2018. HE ALSO SAID THAT IF THIS UPWARD TREND CONTINUES, WE EXPECT SOME 106,000 KIDNEY PATIENTS WHO WOULD NEED DIALYSIS BY THE YEAR 2040, OF WHICH 30 PER CENT WILL BE AGED UNDER 45. THE MOST COMMON TYPES OF URINARY STONES IN MALAYSIA WERE CALCIUM OXALATE, URIC ACID AND INFECTIVE STONES. THE MOST COMMON MODE OF TREATMENT FOR URINARY STONES IN MALAYSIA WAS SHOCKWAVE LITHOTRIPSY (45%) FOLLOWED BY RETROGRADE ENDOUROLOGICAL PROCEDURES (35%) AND PERCUTANEOUS NEPHROLITHOTOMY (15%) IN ONE STUDY. 59
CAUSES KIDNEY STONES ARE HARD DEPOSITS OF MINERALS AND SALTSTHAT FORM INSIDE THE KIDNEYS DEHYDRATION: CONSUMING INADEQUATE AMOUNTS OF WATER REGULARLY FOR PROLONGED PERIODS OF TIME GREATLY INCREASES THE RISK OF KIDNEY STONE FORMATION. PEOPLE LIVING IN HOT AND DRY CLIMATES AND WHO SWEAT A LOT ARE ALSO AT INCREASED RISK DIET: A DIET HIGH IN CERTAIN TYPES OF FOODS OR SALTS CAN INCREASE THE CONCENTRATION OF MINERALS AND SALTS IN THE URINE, WHICH CAN LEAD TO CRYSTALLIZATION AND STONE FORMATION. FAMILY HISTORY: PEOPLE WHO HAVE A FAMILY MEMBER WHO HAS HAD KIDNEY STONES ARE MORE LIKELY TO DEVELOP THEM THEMSELVES. THIS MAY BE DUE TO INHERITED FACTORS THAT AFFECT THE METABOLISM OR EXCRETION OF MINERALS AND SALTS IN THE URINE. 60
Treatment MEDICATION: PAINKILLERS, ANTIEMETICS, AND DRUGS THAT HELP RELAX THE MUSCLES OF THE URINARY TRACT OR DISSOLVE THE STONES EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY (ESWL): ANONINVASIVE PROCEDURE THAT USES SOUND WAVES TO BREAKTHE STONES INTO SMALLER PIECES THAT CAN PASS THROUGHURINE PERCUTANEOUS NEPHROLITHOTOMY: A SURGICAL PROCEDURE THAT INVOLVES MAKING A SMALL INCISION IN THE BACK AND INSERTING A TUBE TO REMOVE THE STONES 61
KIDNEY STONES MAY NOT CAUSE ANY SYMPTOMS UNTIL THEY MOVE AROUND IN THE KIDNEY OR PASS INTO THE URETER SYMPTOMS SEVERE PAIN IN THE SIDE AND BACK, RADIATING TO THE LOWER ABDOMEN AND GROIN BLOOD IN URINE NAUSEA AND VOMITING 62
Function: While primarily involved in temperature regulation and protection, the skin contributes to excretion through sweating. Excretion: Sweat glands release sweat, which contains water, electrolytes, and small amounts of waste products like urea. Sweating helps eliminate these waste products and regulate body temperature. Function: The lungs are involved in excretion by expelling carbon dioxide, a waste product of cellular respiration, during exhalation. Excretion: As breathed out, carbon dioxide is released from the body, helping to maintain the body's acid-base balance. Function: The large intestine is involved in the final stages of digestion and water absorption. Excretion: It eliminates solid waste, including undigested food, bacteria, and waste products, through feces. While it's not the primary organ for waste elimination, it contributes to the removal of some waste and toxins. Excretory Organs Excretion is the process of eliminating waste products and excess substances from the body. Each of the organs plays a specific role in excretion: Function: The kidneys are the primary excretory organs in the body. Excretion: They filter blood to remove waste products, excess salts, and excess water, forming urine. Kidneys Skin Liver Lungs Function: The liver is primarily involved in metabolic processes and detoxification rather than direct excretion. Excretion: The liver produces bile, which contains waste products like bilirubin. Bile is stored in the gallbladder and released into the small intestine to aid in digestion and excrete waste products. Large Intestine 63
AWARENESS AND EDUCATION EARLY DETECTION PREVENTIVE HEALTHCARE COMMUNITY ENGAGEMENT INTERNATIONAL COLLABORATION TELEMEDICINE AND TECHNOLOGY 1. 2. 3. 4. 5. 6. In the early stages despite many patients being symptomless some patients can experience fatigue, muscle cramps, nausea, itchy skin, headaches, and loss of appetite In later stages, development of complications including cardiovascular disease, bone and muscle problems, sleep apnoea, and anaemia Possible clinical outcomes, including: BY STEPHANIE W.X.Y & CHAI YI LIN According to the National Action Plan for Healthy Kidneys (ACT-KID) 2018-2025, the incidence and prevalence of treated ESKD have risen markedly over the last 25 years. The Malaysian Dialysis and Transplant Registry reported that 7,967 new patients received dialysis in 2015 and by the end of 2016 there were 39,711 patients on dialysis. ESRD in which the kidney function is no longer sufficient to sustain life. In these cases, some form of kidney replacement therapy (dialysis or transplant) is necessary Early Detection and Secondary Prevention Screening of high-risk groups Blood pressure control Glycaemic control Smoking cessation Medication management in relation to kidney disease STEPS I to address ESRD in Malaysia end-stage renal disease (ESRD) 64