Physiology - Glomerular filtration rate

Question 1

what is the functional unit of the kidney?

a.bowmans capsule
b.nephron
c.papilla
d.renal cortex

Answer 1

b.nephron

Question 2

where are the 2 capillary beds of the renal circulation found

a. around PCT and DCT
b. in the glomerulus and around tubules and loop of henle
c.around glomerulus and loop of henle

Answer 2

b. in the glomerulus and around tubules and loop of henle

Question 3

which arteriole of the glomerulus is large in diametre and carriers higher pressure blood`?

a.afferent
b.efferent

Answer 3

a.afferent

carries blood in at high pressure

Question 4

peritubular capillaries coming from which arteriole of the glomerulus supply the tubules

a.afferent
b.efferent

Answer 4

b.efferent

Question 5

what are the additional branches of the efferent arteriole that lead towards the loop of henle known as?

a.peritubular
b.vasa rectae

Answer 5

b.vasa rectae

involved in water and sodium resorption

Question 6

which pole of the glomerulus are the arterioles found at

a.vascular
b.tubular

Answer 6

a.vascular

Question 7

which end of the glomerulus is the juxtaglomerular apparatus found ?

a.vascular
b.tubular

Answer 7

a.vascular

Question 8

what do cells of the vascular side of the JG apparatus sense and respond to

a. blood pressure
b.sodium

Answer 8

a. blood pressure

Question 9

what do cells of the tubular side of the JG apparatus sense and respond to

a. blood pressure
b.sodium

Answer 9

b.sodium

Question 10

what cell type has branching arms called end feet that encapsulate the capillaries of the glomerulus allowing for glomerular filtration in the gaps between these feet

a.kupffer cells
b. podocytes
c. sphereocytes
d. c cells

Answer 10

b. podocytes

Question 11

glomerular filtration refers to the process by which water and some solutes pass from the glomerular capillary into which other structure

a.bowmans capsule
b. distal convuluted tubule
c. blood
d. loop of henle

Answer 11

a.bowmans capsule

Question 12

what make up the three layers that substances undergoing glomerular filtration hae to pass through

Answer 12

fenestrated capillary
basement membrane
podocytes

Question 13

what structures are responsible for forming a barrier to large proteins exiting the blood

a. glycocalyx
b.major calyx
c. minor calyx
d.podocytes

Answer 13

a. glycocalyx

look like cacti sprouting out of endothelial cells

Question 14

what structure is responsible for stopping small proteins from leaving the blood

a.glycocalyx
b.major calyx
c.basement membrane
d. bowmans capsule

Answer 14

c.basement membrane

and proteins from podocytes jutting out into podycytes slits

Question 15

equation for capillary filtration pressure

Answer 15

(Hydrostatic Pressure arterial - Hydrostatic pressure venous.) - (osmotic pressure arterial - osmotic pressure venous)

Question 16

what is the hydrostatic pressure of the bowmans capsule determined by?

a,proteins in filtrate
b. proteins in the plasma

Answer 16

a,proteins in filtrate

Question 17

what is the hydrostatic pressure of the glomerular capillaries determined by?

a,proteins in filtrate
b. proteins in the plasma

Answer 17

b. proteins in the plasma

Question 18

what is the equation for glomerular net filtration pressure

Answer 18

(hydrostatic pressure glomerular capillary - hydrostatic pressure bowmans capsule ) - (osmotic pressure glomerular capillary - osmotic pressure bowmans capsule)

(HPGC - HPBC) - (OGC- OBC)

Question 19

GFR is determined by NFP of the glomerulus but also filtration coefficient K. what does K represent

a. osmotic pressure

b. concentration of filtrate and surface area of the glomerular capillary

c. ease at which the fluid can move through a pore and the surface area of the glomerular capillary

Answer 19

c. ease at which the fluid can move through a pore and the surface area of the glomerular capillary

Question 20

glomerular filtration rate

Answer 20

rate at which a substance x is cleared from the blood into the urine when the substance x is freely filtered and is neither reabsorbed or excreted from the kidneys

urine [x]. x urine flow / plasma [x]

Question 21

equation for gfr

Answer 21

urine [x]. x urine flow / plasma [x]

Question 22

what substance is used to test GFR

a.creatine
b.creatinine
c.albumin

Answer 22

b.creatinine

Creatinine is produced naturally by the body (breakdown product of creatinine phosphate, which is found in muscle).
It is freely filtered by the glomerulus, but also actively secreted by the peritubular capillaries in very small amounts
such that creatinine clearance overestimates actual GFR by 10-20%.
↓clearance = ↑plasma[creatinine] = ↓renal function

Question 23

what happens to plasma creatinine when renal function is reduced

a.increase
b.decrease
c.no change

Answer 23

a.increase

reduced kidney function = less creatinine excretion = more left in [plasma

Question 24

what effect does hypertension have on GFR

a.initial increase, long term decrease

b.initial decrease, long term increase

c.increase

d.decrease

Answer 24

a.initial increase, long term decrease

high bp in glomerulus makes kidney vulnerable to damage can rupture gc
scarring and atherosclerosis reduces renal BF
can cause renal failure

Question 25

what happens to GFR during sleep a.increase b.decrease

Answer 25

b.decrease ADH and plasma protein variations meaning you dont need to get up in the night to urinate nocturia is a sign of hypertension

Question 26

what effect does excercise have on gfr a. increase b. decrease

Answer 26

b. decrease blood directed to muscles instead

Question 27

what happens when the afferent arteriole is constricted eg by ADH a.reduced renal blood flow , reduced filtration pressure due to drop in hydrostatic pressure b. reduced renal blood flow , increased filtration pressure c.reduced renal blood flow , maintained filtration pressure

Answer 27

a.reduced renal blood flow , reduced filtration pressure due to drop in hydrostatic pressure

Question 28

what happens when the efferent arteriole is constricted eg by Angiotensin 2 a.reduced renal blood flow , reduced filtration pressure due to drop in hydrostatic pressure b. reduced renal blood flow , increased filtration pressure c.reduced renal blood flow , maintained filtration pressure

Answer 28

b. reduced renal blood flow , increased filtration pressure

Question 29

what happens when the efferent and afferent arteriole both. constrict a.reduced renal blood flow , reduced filtration pressure due to drop in hydrostatic pressure b. reduced renal blood flow , increased filtration pressure c.reduced renal blood flow , maintained filtration pressure

Answer 29

c.reduced renal blood flow , maintained filtration pressure

Question 30

what happens if bp increases? a.myogenic vasoconstriction in afferent arteriole b.myogenic vasoconstriction in the efferent arteriole c. sensed by jg apparatus of afferent arteriole leading to renin release

Answer 30

a.myogenic vasoconstriction in afferent arteriole

Question 31

what happens if bp decreases? a.myogenic vasoconstriction in afferent arteriole b.myogenic vasoconstriction in the efferent arteriole c. sensed by jg apparatus of afferent arteriole leading to renin release

Answer 31

c. sensed by jg apparatus of afferent arteriole leading to renin release

Question 32

renal blood flow is measured using clearance this is the volume of ................ that is cleared of a particular substance in 1 min calibrated for amount of blood made up by plasma a.urine b.plasma c. filtrate d.blood

Answer 32

b.plasma

Question 33

what substance is used in measurement of renal flow a.creatinine b.insulin c.PAH d.albumin

Answer 33

c.PAH cleared in 1 circuit through kidney

Question 34

equation for clearance of PAH

Answer 34

[urine PAH] x urine flow rate / arterial [plasma PAH]

Question 35

equation for converting renal plasma flow to renal blood flow

Answer 35

RPF / (1- Haematocrit)