regulation of GFR and blood pressure

Question 1

what is the glomerular filtration rate

Answer 1

volume of fluid filtered from the glomerular capillaries into bowman’s space per minute

Question 2

what is the glomerular capillary pressure

Answer 2

driving force for filtration

Question 3

what is the glomerular capillary pressure regulated by

Answer 3

afferent and efferent arterioles

Question 4

what happens if GFR is too high

Answer 4

too much filtrate
increased urine production
insufficient time for reabsorption due to increased flow rate and substances lost in urine

Question 5

what happens in GFR is too low

Answer 5

too little filtrate
reduced flow of filtrate
certain waste substances may not be excreted and will accumulate in the body

Question 6

what happens to GFR when afferent arteriole constricts

Answer 6

decreases

Question 7

what does renal autoregulation do

Answer 7

maintains stable GFR when small/moderate changes in blood pressure

Question 8

what are the 2 mechanisms of renal autoregulation

Answer 8

mycogenic response - belt
tubuloglomerular feedback - braces

Question 9

what change does mycogenic respond to

Answer 9

change in blood pressure in afferent blood pressure

Question 10

what change does tubuloglomerular feedback respond to

Answer 10

change in sodium in ascending LOH

Question 11

what are macula densa cells and where are they found

Answer 11

lie within the nephron and detect actual changes in sodium therefore fluid volume
send paracrine signal to adjacent myocytes afferent arteriole
signal results in vasoconstriction or vasodilation

Question 12

what is the mycogenic response to an increase in BP in afferent arteriole

Answer 12

detects increase blood pressure and causes vasoconstriction

Question 13

what is the mycogenic response to a decrease in BP in afferent arteriole

Answer 13

detects decrease in blood pressure and causes vasodilation

Question 14

neural regulation of blood pressure

Answer 14

baroreceptor reflex

Question 15

hormonal regulation of blood pressure

Answer 15

angiotensin II

Question 16

where is angiotensinogen synthesised and where is it released

Answer 16

liver and released into plasma

Question 17

why is renin released

Answer 17

in response to a decrease in blood pressure

Question 18

function of aldosterone

Answer 18

increases reabsorption of sodium and chlorine
increases blood pressure and decreases potassium

Question 19

osmotic consequence of increased reabsorption of sodium and chlorine

Answer 19

more water reabsorbed
increases blood volume
increases venous return and stroke volume

Question 20

effect of constriction of afferent arteriole

Answer 20

reduces blood flow to glomerular capillaries
reduces hydrostatic pressure
decreases GFR

Question 21

effect of constriction of efferent arteriole

Answer 21

reduces blood flow to the glomerular capillaries
increases hydrostatic pressure helps preserve GFR
relatively small decreases in GFR