Kidneys

Question 1

How is urea removed from the blood?

Answer 1

Hydro static pressure generated causing ultrafiltration at bowman’s capsule through basement membrane

Question 2

Why would blood glucose of a diabetic person be higher than a non diabetic person an hour after eating?

Answer 2

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

Question 3

Why does the urine of a diabetic person not contain any glucose?

Answer 3

Glucose leaves the blood at the kidney and reabsorbed in the 1st convoluted tubule

Question 4

Why can a high blood glucose concentration cause glucose to be present in the urine of a diabetic person?

Answer 4

A large concentration of glucose in filtrate, which cant all be reabsorbed in the 1st convuluted tubule.

Question 5

What is the functional unit of the kidney?

Answer 5

Nephron

Question 6

Blood enters the kidney via what artery?

Answer 6

Renal artery

Question 7

Blood leaves the kidney via what vein?

Answer 7

Renal vein

Question 8

What happens in the bowmans capsule?

Answer 8

Ultra filtration

Separation of large particles from small

Question 9

What happens in the PCT?

Answer 9

Selective re absorption

Question 10

What happens in the DCT?

Answer 10

Osmoregulation

Varies amount of water reabsorbed into blood

Question 11

What happens in the descending limb?

Answer 11

Salts are added and water is removed, which decreases water potential

Question 12

What happens in the ascending limb?

Answer 12

water potential increased as salts removed by active transport

Question 13

what happens in the collecting duct?

Answer 13

Water potential is decreased as water is removed

Question 14

What would be a symptom of diabetes?

Answer 14

Excessive urination

Question 15

From which gland is ADH released?

Answer 15

Pituitary gland

Question 16

What part of the brain acts as the coordinator in the control of water balance.

Answer 16

Hypothalamus

Question 17

What is meant by negative feedback?

Answer 17

A change triggers a response which reduces the effect of a change

Question 18

where are the osmoreceptors in a mammal?

Answer 18

Hypothalamus

Question 19

What does ADH do?

Answer 19

Increases permeability of cells therefore more water is absorbed from DCT

Question 20

Why does the cell volume of an osmorecptor decease when a person is dehydrated?

Answer 20

Water potential decreases when dehydrated. Water potential in osmoregulator is higher so water moves from osmoreceptor into blood by osmosis.

Question 21

What is osmoregulation?

Answer 21

Control of the water potential of the blood

Question 22

What is a nephron?

Answer 22

The functional unit of the kidney which filters out waste products

Question 23

Apart from eating and drinking what other ways are there to obtain water

Answer 23

Metabolic water from aerobic respiration

Question 24

Explain the role of the loop of henle in the absorption of water from the glomerular filtrate

Answer 24

Ascending limb Na+ ions removed 
Ascending limb impermeable to water 
Descending limb water moves out
Low water potential 
Water leaves collecting duct by osmosis

Question 25

Why is a large amount of ADH beneficial for organisms living in the desert?

Answer 25

More water from filtrate reabsorbed by osmosis

Question 26

Where does ADH act?

Answer 26

Collecting duct, distil convulted tubule, second convoluted tubule

Question 27

Why is a long loop of henle beneficial?

Answer 27

Allows more salt re absorption into the medulla, leading to greater osmotic pressure which leads to more water re absorption