Ch16 Kidney

Question 1

Osmoregulation

Answer 1

1. Ultrafiltration
2. Reabsorption
3. Medulla Na+ gradient
4. Reabsorption of water

Question 2

Ultrafiltration

Answer 2

1. Hydrostatic pressure in glomerulus than bowman’s capsule
2. Small molecules such as water, glucose and ions
3. pass through basement membrane
4. proteins are too large to go through
5. podocytes in renal capsule
6. glomerular filtrate produced

Question 3

Adaptations of glomerulus

Answer 3

1. afferent arteriole has greater diameter of efferent arteriole
2. high hydrostatic pressure
3. endothelium have pores(filtrate)
4. podocytes

Question 4

Reabsorption

Answer 4

1. Na+ actively transported out of proximal convoluted tubule into blood capillaries
2. Na+ diffuse down concentration gradient from lumen into cells lining proximal convoluted tubule
3. co-transport occurs with Na+ ions through carrier proteins
4. glucose, amino acids and ions
5. molecules then diffuse down concentration gradient into blood capillaries

Question 5

Proximal convoluted tubule adaptations

Answer 5

1. microvilli and infoldings- large SA for reabsorption
2. high density mitochondria to provide ATP for active transport

Question 6

Loop of Henle

Answer 6

1. Na+ ions actively transported out of ascending limb
2. ascending limb impermeable to water
3. lowers water potential in medulla
4. water moves out descending limb via osmosis
5. Na+ ions diffuse into bottom of descending limb
6. water leaves collecting duct via osmosis down water potential gradient

Question 7

Distal convoluted tubule

Answer 7

1. reabsorbs material from filtrate via active transport
2. water diffused out via osmosis down water potential gradient
3. remains transported to urine

Question 8

Longer loop of Henle

Answer 8

1. more ions actively transported out of ascending limb
2. concentration of ions increases down medulla- lower water potential
3. more water reabsorbed by osmosis
4. from collecting duct into blood

Question 9

ADH low wpt

Answer 9

1. detected by osmoreceptors in hypothalamus- sends nerve impulses
2. posterior pituitary gland secretes ADH
3. ADH increases number of aquaporins in DCT/collecting duct- more permeable
4. more water is reabsorbed into blood via osmosis down water potential gradient
5. more concentrated urine produced

Question 10

ADH

Answer 10

antidiuretic hormone
binds with csm receptors
activates enzyme phosphorylase
cell vesicles move and fuse with csm
increase number aquaporins

Question 11

Role of the nephron

Answer 11

1. filter the blood
2. removes waste
3. selectively reabsorbs useful substances