Life sciences Grade 11 CAPS structured, clear, practical - Helping teachers unlock the power of NCS KNOWLEDGE AREA: Life Process in Plants and Animals. TOPIC 5.4: Excretion Diseases, Disorders and Injuries leading to Kidney Failure

Summary of presentation Diseases and Disorders Injuries Kidney Failure Treatment

Diseases and Disorders Kidney Stones: Salts and wastes dissolve in the water of filtrate, before it is excreted from the body. Sometimes salts like calcium and urea do not dissolve. They form crystals. These crystals are called kidney stones. These stones move through the kidney with the urine. The kidney stones vary in size. Kidney stone in the ureter

Diseases and Disorders If they are very large they can cause pain. Stones that are larger than 2cm are removed surgically. Smaller stones are removed by shockwave therapy. During shockwave therapy the stones are shattered into small pieces and then are passed out with the urine. Treatment using shock wave therapy

Terminology: TERM: DEFINITION: USE IN SENTENCE: Kidney stones Kidney stones are crystals of salts that are formed when these salts do not dissolve in the water of the filtrate. USE IN SENTENCE: When calcium does not dissolve in the water of the filtrate it forms kidney stones.

Terminology: TERM: DEFINITION: USE IN SENTENCE: Shock wave therapy A treatment for smaller kidney stones where they are bombarded with high energy shock waves that break them up to small pieces. USE IN SENTENCE: Kidney stones that are smaller than 2cm are treated using shock wave therapy.

Diseases and Disorders Bladder and Kidney Infections: Cystitis: This is the inflammation of the bladder. This infection is caused by bacteria. The bacteria spreads from the intestine through the anus and then into the urethra. Symptoms: Fever Blood in urine Frequent urination Burning sensation during urination

Diseases and Disorders Treatment: Treated using antibiotics. However if no treatment occurs then it can cause an infection called pyelonephritis. This occurs when the bacteria travels up the ureters. This then causes infection of the kidneys.

Terminology: TERM: DEFINITION: USE IN SENTENCE: Pyelonephritis Infection that develops when a bladder or kidney infection is not treated. USE IN SENTENCE: Pyelonephritis will develop if a bladder infection is not treated.

Diseases and Disorders Bilharzia: This disease is caused by a parasite called Schistosoma. This parasite needs two hosts to complete its lifecycle. These two hosts are: A specific species of snail and Humans. Schistosoma

Terminology: TERM: DEFINITION: USE IN SENTENCE: Schistosoma Parasite that causes Bilharzia. USE IN SENTENCE: Bilharzia is caused by the Schistosoma parasite.

Diseases and Disorders Lifecycle of the Bilharzia parasite

Diseases and Disorders A Brief overview of the lifecycle of the Bilharzia parasite: The larval stages pass out from the snail into the water. This stage is called the cercaria. The cercaria stage then bores into the human body through the skin. It enters the blood system. In the human body the cercaria develop into the adult stage.

Diseases and Disorders As adults they mate and produce eggs. Each egg has a sharp spine. These eggs come to lie in the blood vessels of the bladder or rectum. The eggs then pierce the blood vessels and enter the bladder or rectum. This causes blood to pass into the bladder or rectum. If a person infected with this parasite passes faeces or urine into the water, the eggs hatch.

Terminology: TERM: DEFINITION: USE IN SENTENCE: Cercaria Larval stage of the Bilharzia parasite. USE IN SENTENCE: The cercaria passes out into the water, from the snail.

Diseases and Disorders Remember that a person infected with the parasite will pass some blood together with the faeces or urine. The eggs hatch into the miracidia. These miracidia enter the snail, where they continue their lifecycle. Can you explain how the spread of this disease can be avoided?

Solution: Use toilets, instead of passing faeces or urine in the water. Doctor or health can prescribe medication for the treatment of people infected by this disease.

Terminology: TERM: DEFINITION: Miracidia USE IN SENTENCE: Stage in the lifecycle of the bilharzia parasite that enters the snail. USE IN SENTENCE: Once the eggs hatch they develop into miracidia.

Injuries: Injuries to the kidneys can occur through back injuries. Your back maybe injured during sports or accidently by falls or during car accidents. The treatment is determined by the extent of the injury. The extent of the injury is dependent on the type and seriousness of the injury. Sport injuries of the back can be prevented by using protective clothing during sports. Such as corsets or back braces.

Injuries: Corsets used to prevent back injuries

Kidney Failure: The 2 main functions of the kidney is to: Filter the blood and Maintain homeostasis If the kidney is unable to function then wastes collect in the body. We then say that the person suffers from kidney or renal failure. There are 2 types of renal failure. These are: Acute renal failure Chronic renal failure Now lets look each of these.

Kidney Failure: Acute kidney failure: This occurs when the kidney suddenly fails. It usually occurs for one of three reasons. These are: after serious surgery, severe injury or when the blood vessels leading to the kidney are blocked.

Kidney Failure: Chronic Kidney Failure: This develops slowly. In the early stages there are few symptoms or signs of this disease. Therefore a person may not be aware of the kidney failure until about 25% of the kidney function is lost. This disease is usually caused by high blood pressure or diabetes.

Kidney Failure: Medical treatment may improve the functioning of the kidney. But if the function of the kidney drops to 15% and lower the waste materials stay in the body. This means that homeostasis is not maintained. The person becomes very ill. At this stage the only treatment is a kidney transplant or dialysis.

Terminology: TERM: DEFINITION: USE IN SENTENCE: Acute kidney failure Sudden failure of the kidney. USE IN SENTENCE: Acute kidney failure usually occurs suddenly

Terminology: TERM: DEFINITION: USE IN SENTENCE: Chronic kidney failure Kidney failure that develops slowly with few symptoms. USE IN SENTENCE: When the kidney failure develops over time it results in chronic kidney failure.

Treatment: Dialysis: Dialysis is the removal of waste products from the body using a machine. There are 2 types of dialysis. These are: Haemodialysis Peritoneal dialysis Lets look at each of these in some detail.

Terminology: TERM: DEFINITION: USE IN SENTENCE: Dialysis The removal of waste products from the body using a machine. USE IN SENTENCE: Kidney failure can be treated with dialysis.

Treatment: Haemodialysis: During this procedure a person’s blood is passed through a machine. The machine removes the impurities from the blood. The filtered blood is then returned to the person’s body. In other words the machine filters the blood. Therefore we can say that the machine acts as an artificial kidney. This machine is called a haemodialysis machine. Now lets look at the this machine.

Treatment: 2 From the diagram we can see that the machine is made up of the following parts: A needle A pump that is used to pump the blood into the dialyser. A dialyser is made up of many tubes called the dialysis tube. The dialysis tube acts as a semi permeable membrane. 3 Haemodialysis

Treatment: The dialysis tubes are filled with and surrounded by a fluid called the dialysis fluid. The used dialysis fluid leaves the apparatus through a tube. The dialysis fluid in the machine is topped up with clean fluid by another tube. 4 5 6 7 Haemodialysis

Treatment: A warm water bath is used to ensure that the dialysis fluid is kept at a constant temperature. Now lets look at the process of haemodialysis

Treatment: 1 2 A needle is inserted into a large blood vessel in either the arm or leg. The needle is connected to a pump by a tube. The blood is then pushed to the dialyser by the pump. The blood flows through the dialysis tubes. 3 Process of Haemodialysis

Treatment: As it flows through these tubes waste substances from the tubes enter the surrounding fluid by diffusion. These substances move down a concentration gradient. What does this mean? There is a region of high concentration and a region of low concentration. Process of Haemodialysis

Treatment: The blood and the fluid in the dialyser flow in opposite directions. This type of flow is called counter current blood flow. The advantage of counter current blood flow is that it increases the rate at which the waste substances diffuse out of the blood and into the dialysis fluid. This increase ensures that the process occurs at a faster rate. The cleansed blood then re-enters the body by inserting a needle into the vein. Each treatment lasts for up to 4 hours, and must be done 2 to 4 times a week.

Terminology: TERM: DEFINITION: USE IN SENTENCE: Counter current flow The opposite direction of flow of the blood and fluid in the dialyser. USE IN SENTENCE: The counter current blood flow ensures that the haemodialysis occurs at a faster rate.

Treatment: Peritoneal Dialysis: The peritoneum is a membrane that lines the abdominal cavity. During this type of dialysis, blood is filtered within the abdominal cavity, using the peritoneum. Position of Peritoneum

Terminology: TERM: DEFINITION: USE IN SENTENCE: Peritoneum Membrane lining the abdominal cavity. USE IN SENTENCE: Peritoneal dialysis filters the blood using the peritoneum.

Treatment: Lets look at the apparatus involved in peritoneal dialysis. The dialysis involves the peritoneum, a catheter, dialysing fluid and a second bag for waste fluid. Now lets look at the process.

Treatment: A catheter is inserted in the abdominal cavity in such a way that one end lies within the abdomen and the other lies outside the abdomen. This is done surgically. Dialysing fluid is attached to the catheter lying outside the body. This fluid is called the dialysate. This fluid enters the abdominal cavity.

Treatment: Waste from the blood now diffuses into this fluid across the peritoneum. The bag is replaced after 4-6 hours by fresh fluid. Sometimes a machine maybe used to pump the fluid into the abdominal cavity. The patient can learn to do this dialysis at home. This is usually done at night. The open end of the catheter (outside the body) is clamped during the day. The advantage of this type of dialysis gives the patient more freedom to move about. It also allows the patient to lead a more normal life because he/she only needs to visit the doctor once a month for a check up.

Treatment: Kidney Transplants: Kidney transplant is not regarded as an emergency, because dialysis can be used for many years. But sometimes dialysis does not work, then a kidney transplant becomes an emergency. The person who donates the kidney is called the donor. The donor can be a relative or an unrelated person. Remember that if the donor is not a relative then a cross match must be done to ensure that the donor and recipient share the same gene structure.

Treatment Once a donor is found, the new kidney is transplanted as close as possible to the old kidney. The blood vessels and ureters of the old kidney are attached to the new kidney. The old kidney is not removed because it reduces the time spent on the operating table since the old kidney shrivels up to a very small size. If there is a close genetic match the new kidney can function for 10 to 12 years.

Terminology: Kidney donor: person who donates a kidney Peritoneum: membrane lining the abdominal cavity. Peritoneal dialysis: blood is filtered within the abdominal cavity using the peritoneum. Kidney stones: are crystals of salts that are formed when these salts do not dissolve in the water of the filtrate. Shock wave therapy: treatment for smaller kidney stones where they are bombarded with high energy shock waves that break them up to small pieces.

Terminology: Cystitis: is the inflammation of the bladder caused by bacteria. Pyelonephritis: infection that develops when a bladder or kidney infection is not treated. Schistosoma: parasite that causes Bilharzia. Cercaria: larval stage of the Bilharzia parasite. Miracidia: stage in the lifecycle of the bilharzia parasite that enters the snail. Acute kidney failure: sudden failure of the kidney.

Terminology: Chronic kidney failure: kidney failure that develops slowly with few symptoms. Dialysis: the removal of waste products from the body using a machine. Haemodialysis: is a type of dialysis during which a person’s blood is passed through a machine to be filtered. Counter current flow: when the blood and fluid in the dialyser flow is opposite directions.

Question 1 During a kidney transplant the donor must be … A. A close relative B. Unrelated C. Unrelated but a close genetic match D. Both A and C

Question 2 A successful kidney transplant may last for… A. 10 to 12 years B. 3 to 5 years C. 10 to 12 months D. 10 to 12 days

An important property of the dialysis tube that is used in dialysis is that it is… A. Semi permeable B. Permeable C. Not permeable D. Both A and B Question 3

Question 4 The dialysis machine has many small channels because… A. It makes the process faster B. It is necessary for counter current blood flow C. It increase surface area for maximum filtration D. It prevents counter current blood flow

The blood flowing in an opposite direction to the dialysis fluid in the dialyser is called… A. Osmosis B. Osmoregulation C. Homeostasis D. Counter current blood flow Question 5

Question 6 A kidney transplant is a better way of treating kidney failure than dialyses because… A. It is a more permanent solution B. The patient has to go to hospital once or twice a week C. Both A and B D. None of the above

Question 7 Differences between haemodialysis and peritoneal dialysis is… A. Filtration occurs within the abdomen in peritoneal dialysis and within a machine in haemodialysis B. Peritoneal dialysis can occur continuously while haemodialysis takes place 2 to 4 times a week C. During haemodialysis the dialysis fluid stays inside the machine, while in peritoneal dialysis the fluid enter the abdomen D. All of the above

Peritoneum is… A. Another word for kidney B Peritoneum is… A. Another word for kidney B. Membrane lining the abdominal cavity C. Membrane lining the kidney D. Another word for renal capsule Question 8

Question 9 When the kidney suddenly fails this is called… A. Renal failure B. Acute kidney failure C. Chronic kidney failure D. None of the above

Question 10 When kidney fails slowly with little symptoms, it is called… A. Renal failure B. Acute kidney failure C. Chronic kidney failure D. None of the above

Treatment for kidney failure can be… A. Kidney transplant B. Dialysis C. Both A and B D. Neither A nor B Question 11

Question 12 The parasite that causes Bilharzia is… A. Mycobacterium B. Schistosoma C. E. Coli D. None of the above

Question 13 Miracidia is the… A. Larval stage of the bilharzia parasite. B. Adult stage of the bilharzia parasite. C. What the egg develops into after it hatches D. None of the above Question 13

Question 14 Cercaria is the … A. Larval stage of the bilharzia parasite. B. Adult stage of the bilharzia parasite. C. What the egg develops into after it hatches D. None of the above

Question 15 Cystitis is… A. Inflammation of the bladder B. Infection of the kidney C. infection of the renal tubule D. Infection of the renal capsule

Question 16 Symptoms of cystitis is/are… A. Fever B. Blood in urine C. Frequent need to urinate D. All of the above

Question 17 If cystitis is not treated it can develop into… A. Kidney stones B. Malaria C. Influenza D. Pyelonephritis

Question 18 Cystitis can be treated by… A. Antibiotics B. Shock wave therapy C. Dialysis D. Kidney transplant

Question 19 Cystitis is caused by… A. Virus B. Fungi C. Bacteria D. Protist

Question 20 Kidney stones are treated by… A. Antibiotics B. Shock wave therapy C. Dialysis D. Kidney transplant

SOLUTIONs final assessment questions D A C B C B A D