Physiology - Glomerular filtration rate Flashcards

1
Q

what is the functional unit of the kidney?

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

A

b.nephron

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2
Q

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

A

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

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3
Q

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

a.afferent
b.efferent

A

a.afferent

carries blood in at high pressure

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4
Q

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

a.afferent
b.efferent

A

b.efferent

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5
Q

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

a.peritubular
b.vasa rectae

A

b.vasa rectae

involved in water and sodium resorption

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6
Q

which pole of the glomerulus are the arterioles found at

a.vascular
b.tubular

A

a.vascular

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7
Q

which end of the glomerulus is the juxtaglomerular apparatus found ?

a.vascular
b.tubular

A

a.vascular

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8
Q

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

a. blood pressure
b.sodium

A

a. blood pressure

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9
Q

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

a. blood pressure
b.sodium

A

b.sodium

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10
Q

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

A

b. podocytes

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11
Q

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

A

a.bowmans capsule

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12
Q

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

A

fenestrated capillary
basement membrane
podocytes

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13
Q

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

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

A

a. glycocalyx

look like cacti sprouting out of endothelial cells

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14
Q

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

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

A

c.basement membrane

and proteins from podocytes jutting out into podycytes slits

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15
Q

equation for capillary filtration pressure

A

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

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16
Q

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

a,proteins in filtrate
b. proteins in the plasma

A

a,proteins in filtrate

17
Q

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

a,proteins in filtrate
b. proteins in the plasma

A

b. proteins in the plasma

18
Q

what is the equation for glomerular net filtration pressure

A

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

(HPGC - HPBC) - (OGC- OBC)

19
Q

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

A

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

20
Q

glomerular filtration rate

A

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]

21
Q

equation for gfr

A

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

22
Q

what substance is used to test GFR

a.creatine
b.creatinine
c.albumin

A

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

23
Q

what happens to plasma creatinine when renal function is reduced

a.increase
b.decrease
c.no change

A

a.increase

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

24
Q

what effect does hypertension have on GFR

a.initial increase, long term decrease

b.initial decrease, long term increase

c.increase

d.decrease

A

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

25
Q

what happens to GFR during sleep

a.increase
b.decrease

A

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

26
Q

what effect does excercise have on gfr

a. increase
b. decrease

A

b. decrease

blood directed to muscles instead

27
Q

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

A

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

28
Q

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

A

b. reduced renal blood flow , increased filtration pressure

29
Q

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

A

c.reduced renal blood flow , maintained filtration pressure

30
Q

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

A

a.myogenic vasoconstriction in afferent arteriole

31
Q

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

A

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

32
Q

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

A

b.plasma

33
Q

what substance is used in measurement of renal flow

a.creatinine
b.insulin
c.PAH
d.albumin

A

c.PAH

cleared in 1 circuit through kidney

34
Q

equation for clearance of PAH

A

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

35
Q

equation for converting renal plasma flow to renal blood flow

A

RPF / (1- Haematocrit)