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Description
Flashcards by Hayden McElduff, updated more than 1 year ago
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Created by Hayden McElduff
almost 8 years ago
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| Question | Answer |
| Define Excretion | The removal of wastes resulting from metabolic processes in cells |
| Describe how each of the excretory organs remove wastes | Lungs - CO2 and H2O Skin - sweat salts, urea, lactic acid Liver - processes substances before excretion (e.g. deamination to urea) Alimentary Canal - bile pigments from haemoglobin on erythrocytes Kidneys - water, urea, uric acid, creatinine |
| Describe the livers involvement in breaking down protein | Deamination: Excess proteins not stored in body because they are toxic to cells Broken down into amino acids instead Deamination is the stripping of nitrogen from amino acids and nitrogen bases (RNA) |
| Define deamination | The stripping of nitrogen from amino acids and nitrogen bases |
| Equation for deamination | Amino acid --> ammonia |
| Equation for breakdown of ammonia into urea | Ammonia + CO2 --> urea + water |
| Draw and label a diagram of the kidney. Describe the function of each | See page 125 |
| Draw and label a diagram of a nephron | See page 125 |
| Describe glomerular filtration | When blood enters the glomerulus, high pressure from the change in diameter of the afferent and efferent arterioles, forces water and dissolved blood components through the deferentially permeable cell membranes and into the glomerular capsule. |
| List the substances that are filtered in glomerular filtration | urea water glucose amino acids vitamins salts (mainly sodium & chlorine) |
| Describe selective reabsorption | Occurs because some substances are needed by the cell so they should not be excreted. Substances are reabsorbed back into the blood and taken to the cells that need them |
| List the substances involved in selective reabsorption and where they are reabsobed | Proximal Convolute Tubule - Water, glucose, amino acids, vitamins, salts (mainly sodium and chlorine) Loop of Henle - Salts (mainly sodium and chlorine) Distal Convolute Tubule - Water Collecting Duct - Urine = water, urea, salts |
| Describe Tubular Secretion | The adding of materials to the filtrate from the blood. Removes certain unwanted materials from the body and controls pH of blood. Water and other substances that are not reabsorbed drain from collecting ducts and into the renal pelvis. Urine drains from pelvis into ureters and pushed to urinary bladder where it is stored. |
| List the substances that are secreted from blood to urine during tubular secretion | Ammonium Urea Creatinine Hydrogen Potassium Drugs Neurotransmitters |
| List the composition of urine | ~ 95% water ~ 5% other solutes (including: organic molecules e.g. urea, creatinine and uric acid), ions (mainly sodium and chloride ions) and other metabolic wastes. |
| Describe the causes of kidney stones | Formed when solid crystals build up inside kidneys. Usually form when urine is too concentrated. May be caused by insufficient fluids in diet. If crystals are small enough they can pass down the ureter and out of the blood through the urethra without being noticed. Crystals can combine to make stones. Large stones can get stuck in ureter, bladder or urethra, causing pain. |
| Describe lifestyle measures that could maintain healthy kidneys | Regulate diet to keep healthy weight - Overweight can cause diabetes and high blood pressure - major factors for kidney disease. Do not smoke - three times more likely to have impaired kidney function if smoke Drink water instead of sugary drinks Do not use performance enhancing drugs - may upset water balance in body. Can cause scaring and failure. |
| Describe peritoneal dialysis | Peritoneum is a membrane that lines the inside of the abdominal cavity and covers organs such as the stomach, liver and intestines. Very rich blood supply. Peritoneal dialysis occurs inside body using the peritoneum as a membrane where wastes can be removed. A catheter is placed through the wall of the abdominal cavity. Useful substances stay in blood. Fluid that was placed in abdominal cavity is is drained out through the catheter, along with any wastes and extra water that have diffused from blood. Usually done every day. |
| Describe Haemodialysis | Passing blood through an artificial kidney or dialysis machine. Blood passes through thousands of fine tubes, made of a differentially permeable membrane and immersed in a bath of fluid. Concentrations of fluid are similar to those in the blood, except the fluid has no waste. The concentration difference causes wastes to diffuse from the blood into the fluid. 4-5 hours attached to a machine. 3 times a week |
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