Lec 29

Question 1

GFR is — over wide range of –

Answer 1

constant over raange of BP

Question 2

GFR is regulated by —-

Answer 2

regulationg renal blood flow

Question 3

autoregulation

Answer 3

constant GFR when MAP is between 80 and 180

Question 4

regulate blood flow into glomerulus by

Answer 4

Vasoconstriction and vasodilation of afferent arteriole

Question 5

Vasoconstriction of efferent arteriole

Answer 5

minimal leave
blood pulls in glomerulus
increase Ph
GFR increase

Question 6

Vasoconstriction of afferent arteriole

Answer 6

less blood entering glomerulus
decrease Ph
decrease GFR

Question 7

Vasodilation of afferent arteriole

Answer 7

more blood entering glomerulus
increase ph
icrease GFR

Question 8

mechansim of autoregulation

Answer 8

1-myogenic response to changes in BP
2-vasoconstriction afferent arteriole
3- tubuloglomerular feedback

Question 9

myogenic response to changes in BP:

Answer 9

1- intrinsic ability of vascular smooth muscle
2- stretch due to increased pressure causes vasoconstriction

Question 10

stretch due to increased pressure causes vasoconstriction, how

Answer 10

1- stretch-activated cation channels on vascular smooth muscle
2- depolarization lead to smooth muscle contraction

Question 11

tubuloglomerular feedback

Answer 11

paracrine signalling
- occurs at the juxtaglomerular apparatus (JGA)
- Macula densa: specialized cell in ascending tubule sensing flow

Question 12

JGA

Answer 12

region where ascending limb loop of henle passes between afferent and efferent arterioles

Question 13

macula densa function

Answer 13

sense increase flow due to high GFR
release paracrine
paracrine act on afferent arteriole
Vasoconstriction

Question 14

granular cells

Answer 14

secrete renin, enzyme involve in salt and water balance

Question 15

tubuloglomerular feedback

Answer 15

gfr increase
flow through tubule increase
flow past macula densa increase
paracrine from macula densa on afferent arteriole
Vasoconstriction
resistance increase
hydrostatic pressure decrease
gfr decrease

Question 16

most reabsorption happen in

Answer 16

proximal tubule

Question 17

reabsorption movement

Answer 17

from tubule lumen into blood

Question 18

reabsorption transports

Answer 18

transepithelial transport
paracellular pathway

Question 19

transepithelial transport

Answer 19

transporter apically and basolaterally

Question 20

paracellular pathway

Answer 20

tight junction of adjacent cells

Question 21

reabsorption is primarily driven by

Answer 21

Na movement

Question 22

Na movement through apical membrane

Answer 22

sodium channels called ENaC
no ATP used
conc. gradient

Question 23

Na movement through basolateral membrane

Answer 23

Na/k pump
ATP needed

Question 24

when Na is actively reabsoprbed:

Answer 24

1- anions reabsorption by electrochemical gradient
2- water move by osmosis following solute reabsoprtion
3- glucose, amino acid, metabolite, phosphate co-transport

Question 25

permeable solutes are reabsorbed by

Answer 25

1- paracellular pathway
2- membrane transporters

Question 26

what happen to k pumping inside proximal tubule by Na/K pump

Answer 26

move out of proximal tubule by K leaky channesls

Question 27

Glucose reabsorption

Answer 27

soduim-linked secondary active transport
No ATP required
energy comes from potential gradient of Na

Question 28

glucose diffuse out of basolateral side using

Answer 28

GLUT protein

Question 29

in glomerulus net driving force cause

Answer 29

filteration

Question 30

in peritubular capillaries net driving force cause

Answer 30

reabsorption
(80% of fluid remaining but all proteins still here)

Question 31

Secretion

Answer 31

1-important in homeostatic regulation (K,H)
2-removing organic compound from the body (urea,creatinine,drugs)
3-increase secretion enhances nephron excretion

Question 32

Excretion

Answer 32

at the end of collecting duct, filtrate can no longer modified
output=urine
shouldn’t contain any glucose, aa, other metabolites

Question 33

Capillary feeding nephrons

Answer 33

Peritubular capillaries