Kidneys Flashcards
How is urea removed from the blood?
Hydro static pressure generated causing ultrafiltration at bowman’s capsule through basement membrane
Why would blood glucose of a diabetic person be higher than a non diabetic person an hour after eating?
Diabetics have a reduced sensitivity to insulin and therefore there is a reduced uptake of glucose by cells. This means there is a reduced conversion of glucose to glycogen
Why does the urine of a diabetic person not contain any glucose?
Glucose leaves the blood at the kidney and reabsorbed in the 1st convoluted tubule
Why can a high blood glucose concentration cause glucose to be present in the urine of a diabetic person?
A large concentration of glucose in filtrate, which cant all be reabsorbed in the 1st convuluted tubule.
What is the functional unit of the kidney?
Nephron
Blood enters the kidney via what artery?
Renal artery
Blood leaves the kidney via what vein?
Renal vein
What happens in the bowmans capsule?
Ultra filtration
Separation of large particles from small
What happens in the PCT?
Selective re absorption
What happens in the DCT?
Osmoregulation
Varies amount of water reabsorbed into blood
What happens in the descending limb?
Salts are added and water is removed, which decreases water potential
What happens in the ascending limb?
water potential increased as salts removed by active transport
what happens in the collecting duct?
Water potential is decreased as water is removed
What would be a symptom of diabetes?
Excessive urination
From which gland is ADH released?
Pituitary gland
What part of the brain acts as the coordinator in the control of water balance.
Hypothalamus
What is meant by negative feedback?
A change triggers a response which reduces the effect of a change
where are the osmoreceptors in a mammal?
Hypothalamus
What does ADH do?
Increases permeability of cells therefore more water is absorbed from DCT
Why does the cell volume of an osmorecptor decease when a person is dehydrated?
Water potential decreases when dehydrated. Water potential in osmoregulator is higher so water moves from osmoreceptor into blood by osmosis.
What is osmoregulation?
Control of the water potential of the blood
What is a nephron?
The functional unit of the kidney which filters out waste products
Apart from eating and drinking what other ways are there to obtain water
Metabolic water from aerobic respiration
Explain the role of the loop of henle in the absorption of water from the glomerular filtrate
Ascending limb Na+ ions removed Ascending limb impermeable to water Descending limb water moves out Low water potential Water leaves collecting duct by osmosis
Why is a large amount of ADH beneficial for organisms living in the desert?
More water from filtrate reabsorbed by osmosis
Where does ADH act?
Collecting duct, distil convulted tubule, second convoluted tubule
Why is a long loop of henle beneficial?
Allows more salt re absorption into the medulla, leading to greater osmotic pressure which leads to more water re absorption
