kidney

Question 1

where does blood enter the capillary?

Answer 1

through the renal artery

Question 2

where does ultrafiltration take place?

Answer 2

in the bowmans capsule

Question 3

how is the kidney adapted to ultrafiltration?

Answer 3

the afferent is bigger than the efferent so a high pressure is maintained

lined with epithelium for an extra layer/barrier to larger molecules

basement membrane also included

Question 4

where/when does selective reabsorption take place?

Answer 4

PCT, loop of henle and DCT

Question 5

where do the useful substances go once they have left the PCT, loop of henle and DCT?

Answer 5

back into the surrounding capillary network

Question 6

how is the PCT adapted for reabsorption?

Answer 6

epithelium of walls has microvilli to increase SA

Question 7

how are useful substances reabsorbed into the capillaries along the PCT?

Answer 7

active transport and facilitated diffusion

Question 8

what substances are reabsorbed into the blood?

Answer 8

glucose

amino acids

vitamins

Question 9

what equipment is needed when dissecting a mammals kidney?

Answer 9

mammals kidney

apron

scalpel

lab gloves

dissecting tray

Question 10

control of water potential (without hormones)

Answer 10

ascending limb is impermeable to water so water stays in and NA+ and Cl- ions are actively pumped out

water moves out of the descending limb and is reabsorbed into the capillary network

near the bottom of the loop of henle ions diffuse out further lowering the water potential (walls are impermeable to water so it stays in the tubule)

due to high conc of water, it leaves the collecting duct via osmosis

Question 11

how is water regulated by hormones?

Answer 11

osmoreceptors in the hypothalamus detect the change in WP

a nerve impulse is sent to the posterior pituitary gland to secrete more/less ADH

ADH makes the DCT and the collecting duct more permeable to water

Question 12

how can we detect kidney failure

Answer 12

measure the glomerular filtrate rate

Question 13

problems associated with kidney failure (4)

Answer 13

waste products building up in the blood (weight loss and vomiting)

fluids accumulate in tissues (parts of the body begin to swell)

unbalance ions could cause blood to become too acidic

anaemia

Question 14

3 methods of treating kidney failure

Answer 14

haemodialysis

kidney transplant

peritoneal dialysis

Question 15

haemodialysis

Answer 15

filter a patients blood from an artery by having their blood flow on one side of a partially permeable membrane and the dialysis fluid on the other side

waste products (excess urea and mineral ions) and excess water diffuse across the membrane and into the dialysis fluid

the blood and dialysis fluid flow in opposite directions

Question 16

what are two main issues involved in haemodialysis

Answer 16

patient may feel unwell as waste products and fluid start to build up in their blood

expensive and inconvenient (2/3 sessions a week for 8 hours long)

Question 17

kidney transplant

Answer 17

same blood and tissue type

Question 18

advantages of transplants (3)

Answer 18

cheap

more convenient (less sessions)

patients wont feel unwell between/during sessions

Question 19

disadvantages of kidney transplant (2)

Answer 19

major operation

immune system could reject the new transplant -immunosuppressants could be used but would give the patient a low immune system

Question 20

what hormone is present in urine of a pregnant women?

Answer 20

hCG (human chorionic gonadotropin)

Question 21

if hCG is present?

Answer 21

hCG would bind to the monoclonal antibodies at the end of the stick which contain a blue dye,

the monoclonal antibodies move along the stick and would bind to the immobilised enzymes turning the test strip blue

Question 22

if no hCG is present?

Answer 22

the urine moves along the pregnancy test strip without binding to anything so no colour appears

Question 23

why can urea but not glucose and a typical amount of mineral ions leave the patients blood during a dialysis session?

Answer 23

the dialysis fluid contains no urea, normal plasma levels of glucose and mineral ions so there is no net movement of them

Question 24

peritoneal dialysis

Answer 24

is done inside of the body and used the lining of the abdomen

usually done at home

a catheter enters the abdomen

urea and excess mineral ions leave into the tissue fluid, out across the peritoneal membrane and into the dialysis fluid

Question 25

podocytes

Answer 25

cells located below the basement membrane

Question 26

ADH

Answer 26

secreted by the posterior pituitary gland, binds to the aquapourins so water can leave the collecting duct