Physiology - Glomerular filtration rate Flashcards
what is the functional unit of the kidney?
a.bowmans capsule
b.nephron
c.papilla
d.renal cortex
b.nephron
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
b. in the glomerulus and around tubules and loop of henle
which arteriole of the glomerulus is large in diametre and carriers higher pressure blood`?
a.afferent
b.efferent
a.afferent
carries blood in at high pressure
peritubular capillaries coming from which arteriole of the glomerulus supply the tubules
a.afferent
b.efferent
b.efferent
what are the additional branches of the efferent arteriole that lead towards the loop of henle known as?
a.peritubular
b.vasa rectae
b.vasa rectae
involved in water and sodium resorption
which pole of the glomerulus are the arterioles found at
a.vascular
b.tubular
a.vascular
which end of the glomerulus is the juxtaglomerular apparatus found ?
a.vascular
b.tubular
a.vascular
what do cells of the vascular side of the JG apparatus sense and respond to
a. blood pressure
b.sodium
a. blood pressure
what do cells of the tubular side of the JG apparatus sense and respond to
a. blood pressure
b.sodium
b.sodium
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
b. podocytes
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.bowmans capsule
what make up the three layers that substances undergoing glomerular filtration hae to pass through
fenestrated capillary
basement membrane
podocytes
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. glycocalyx
look like cacti sprouting out of endothelial cells
what structure is responsible for stopping small proteins from leaving the blood
a.glycocalyx
b.major calyx
c.basement membrane
d. bowmans capsule
c.basement membrane
and proteins from podocytes jutting out into podycytes slits
equation for capillary filtration pressure
(Hydrostatic Pressure arterial - Hydrostatic pressure venous.) - (osmotic pressure arterial - osmotic pressure venous)
what is the hydrostatic pressure of the bowmans capsule determined by?
a,proteins in filtrate
b. proteins in the plasma
a,proteins in filtrate
what is the hydrostatic pressure of the glomerular capillaries determined by?
a,proteins in filtrate
b. proteins in the plasma
b. proteins in the plasma
what is the equation for glomerular net filtration pressure
(hydrostatic pressure glomerular capillary - hydrostatic pressure bowmans capsule ) - (osmotic pressure glomerular capillary - osmotic pressure bowmans capsule)
(HPGC - HPBC) - (OGC- OBC)
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
c. ease at which the fluid can move through a pore and the surface area of the glomerular capillary
glomerular filtration rate
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]
equation for gfr
urine [x]. x urine flow / plasma [x]
what substance is used to test GFR
a.creatine
b.creatinine
c.albumin
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
what happens to plasma creatinine when renal function is reduced
a.increase
b.decrease
c.no change
a.increase
reduced kidney function = less creatinine excretion = more left in [plasma
what effect does hypertension have on GFR
a.initial increase, long term decrease
b.initial decrease, long term increase
c.increase
d.decrease
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
what happens to GFR during sleep
a.increase
b.decrease
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
what effect does excercise have on gfr
a. increase
b. decrease
b. decrease
blood directed to muscles instead
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.reduced renal blood flow , reduced filtration pressure due to drop in hydrostatic pressure
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
b. reduced renal blood flow , increased filtration pressure
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
c.reduced renal blood flow , maintained filtration pressure
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.myogenic vasoconstriction in afferent arteriole
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
c. sensed by jg apparatus of afferent arteriole leading to renin release
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
b.plasma
what substance is used in measurement of renal flow
a.creatinine
b.insulin
c.PAH
d.albumin
c.PAH
cleared in 1 circuit through kidney
equation for clearance of PAH
[urine PAH] x urine flow rate / arterial [plasma PAH]
equation for converting renal plasma flow to renal blood flow
RPF / (1- Haematocrit)
