Biology 1b: Kidney Problems & Worksheet on Excretion By Mr. Joshwa O. O. STUDENT’S NAME: ________________ Some Causes for Urinary System disorders: Smoking; Physical trauma; Cancer in Kidney; Old kidney; due to old age; Inflammation of glomerulus; High blood pressure (hypertension); Excess alcohol; leads inhibits ADH hormone; High blood cholesterol; cause narrowing of renal arteries; Sugar diabetes (diabetes mellitus); for longer than ten years; Gynaecological problems in women; Enlarged prostate gland in men; blocking urine flow; especially from 60 years; Infection of kidney drainage tubes (ureter, urinary bladder & urethra); Kidney stones; o Are salt & mineral crystals in kidneys; o Like calcium stones, uric acid stones; o Develops if you often produce concentrated urine due to less water in blood; Severe kidney disorder may cause Kidney Failure (Renal System Failure): May cause dehydration, a build-up of nitrogen wastes in the blood, salt imbalances, anaemia and hypertension; Treatments of Kidney Problems: 1. 2. Treatment of Kidney stones: Larger ones can be surgery, or destroyed with ultra-sound or laser light; Smaller ones can naturally pass out via ureters then urethra; In this case drinking lots of water & medication may be enough; Kidney replacements: a) Kidney Transplant: It is possible to donate one kidney and live. Requires living or recently deceased donor; (there is a big shortage of donors) Organ rejection is a problem: Antibodies & cytotoxic T cells produced to destroy foreign antigens on received kidney; only ~3% rejection rate for relatives, ~10% for non-relative donors. Rejection is lowered by giving: o Anti- organ rejection drugs; Problem is that they are immuno-suppressants; so makes one vulnerable to opportunistic infections; o Monoclonal antibodies (work against body's cytotoxic T cells); o Kidney from a close relative with more similar antigens (tissues typing) b) Artificial kidney (=dialysis): – can be Haemodialysis or peritoneal dialysis; + erythropoietin for RBC formation Haemodialysis: Blood is removed from the body via an access attached to a blood vessel Then taken into an artificial kidney (a dialyzer) to remove the following from the blood: Metabolic wastes like urea, Extra water Extra chemicals like extra glucose, ions; NB: Surgery is done to prepare an access is one of the following: First choice: Fistula: a joining an artery and a vein under the skin; lasts longer & has fewer problems like infections and clotting. But may not be possible if blood vessels are not strong enough. Second choice: Graft: soft plastic tube to join an artery and vein in the arm. After healing of the vascular access regular dialysis follow: 1 Third choice: Catheter; plastic tube in a large vein in neck or chest. Is generally used as a temporary access; at times used for long-term treatment; NB: If access is catheter, it can be connected directly to dialysis tubes without needles. The incoming dialysis fluid (dialysate) into dialysis machine: Warmed up to 370C; Its electrolyte composition is same as normal blood; Has same glucose concentration as blood; 0% wastes like uric acid, urea & creatinine; B: Content of dialysis fluid is manipulated so that wastes can be removed while nutrients/ions/ pH adjusted; Inside the dialysis machine: Dialysate chamber has dialysis fluid; The blood chamber is made of; Several semi-permeable tubular fibres; Flood inside them; Events immediately before & During dialysis: One placed into catheter or fistula; One needle draws blood into a tube; Anti-blood clotting protein (heparin) Is added into blood in the tube; Haemopoietin hormone also added; In dialysis machine: Blood gets into the dialysis machine; It flows in blood chamber in opposite direction To dialysis fluid which is in dialysate chamber; This counter current flow maintains diffusion gradient; The following filtration across dialysis tube; a) Metabolic wastes like urea always diffuse into dialysate b) since fresh dialysate has 0% wastes; The following diffuse from higher to lower concertation region: a) Water, b) Glucose, c) Ions; like, H+ / HCO3+ Large blood proteins & cells don’t diffuse out of blood; Cleaner blood with normal electrolyte balance get exit dialysis machine; Via a tube; Preparation for return: Any bubbles in it broken; Pressure monitored & restored to normal body blood pressure; Cleaned blood returns to you through the other tube; The time needed for your dialysis depends on: How well the affected kidneys work How much fluid gained between treatments How much waste you have is in blood; Type of artificial kidney used. Haemodialysis can be done at: a) Dialysis centre or clinic: 3-4 times per week; 3-4 hours each time; b) At home: - 2 hours daily; less fluid removed each time which; reduces symptoms like: headaches, nausea & cramping. - 6-8 hours each night while asleep; so more hours & more waste removal; NB: A patient may have a trained care partners at home or Some centres monitor dialysis machine remotely via modem or the Internet; Page 2 of 6 Peritoneal Dialysis: Blood is cleaned while inside the body. Blood stays in the arteries and veins that line the peritoneal cavity. Cather is surgically placed in your abdomen (peritoneal cavity); The abdominal area is slowly filled with dialysate (dialysis fluid) through the catheter; Excess materials & Wastes diffuse from blood vessels in abdomen; Into dialysate; After 4 -5 hours the dialysate plus wastes are drained out of the body; Into a waste bag; Patient can go on with his/her during dialysis; It’s done 4 – 5 X a day at home and/or at work; Dialysis vs Transplant: Transplants Advantages Disadvantages Patients can lead a more normal life without having to watch what they eat and drink Must take immune-suppressant drugs which low immunity thus increase the risk of infection Cheaper in the long run Shortage of organ donors Kidney only lasts 8-9 years on average Any operation carries risks Dialysis No or little shortage) Patient must limit their salt and protein intake between dialysis sessions No need for immune-suppressant drugs More Expensive Good alternative where transplant isn’t possible Regular dialysis sessions - impacts on the patient's lifestyle headaches, nausea & cramping. End Page 3 of 6 End Page 4 of 6 Work Sheet There is a part of kidney that detects low blood pressure (low blood volume) & releases enzyme renin which eventually leads to increase in systemic blood pressure. Study the diagram below. Put a circle where enzyme renin would be released. [1] Name that part of kidney nephron. [1] The part is made of 1. ………………… …………………… & 2. Beginning of …………………… ……….....……….. tubule. [2] Parts of urinary system Name the parts labeled in all the diagrams below. Some Functions of Kidney are: Regulate …………………………………………………………………………………… ; Regulate …………………………………..……………………….……………………… Regulate …………………………………………………………………………………….… by producing hormone; Page 5 of 6 Urine formation in Kidney nephron. Blood carrying wastes & excess materials enters the kidney via …………………… ……………………… which branch into smaller arteries till the smallest arteries called ………………………………… ……………………………. . This conduct blood through first capillaries in nephron known as …………………………………….. Here pressure ……………………………………………… of blood occurs. The filtrate is known as ………………………..……… …………………………….. & it lacks: o ………………………………………………. & o …………………..…………………………… found in blood o o because they are ………………………………………… The ………………………………. …………………….. receives the filtrate then passes it to the ……………………………. tubules where useful Substances like ……………………………, …………………………………………………………………… .& ………………………………… are …………………………………………… back to ………………………………………. But wastes, excess substances & drugs (including antibiotics) …………………………………… in urine. Eventually a final fluid called …………………………... is collected from the nephron By the …………………………………. ………………….….………, As filtrate moves along the kidney …………………………, purified blood exits glomerulus via ………………… ….………………… then exits the nephron in venule & eventually exits the kidney via …………………………….. vein. Have you ever seen a water-purification system attached to a faucet? This system removes impurities from the water such as arsenic or other chemicals that can be harmful to people. As water passes through the filters contained in the system, the impurities are trapped on the surface of the filters. Eventually, the water that comes out of this purifier is free of the impurities. Your body has its own system for filtering blood. Why might the blood in your body need to be filtered? ………………………………………………………………………………………………………………………………………………………………………………………………………… What organ(s) do you think filters your blood? ….…………………………………………..……………………………………………………………………………………………………………………………………………………….. How do you think the filtered materials leave your body? …………………………………………………..…………………………………………………………………………………………………………………………………………………… End Page 6 of 6
