Physiology 3

Question 1

name the 3 parts that make up the glomerular membrane

Answer 1

molecular sieve

1. glomerular capillary endothelium
2. basement membrane
3. slit processes of podocytes

Question 2

which is bigger:

afferent or efferent arteriole

Answer 2

afferent arteriole

Question 3

is the basement membrane positively or negatively charged?

Answer 3

BM = negatively charged

Question 4

the gaps between the endothelial cells are too small for what to pass through them?

Answer 4

RBCs

Question 5

is the process of glomerular filtration active or passive?

Answer 5

passive = does not require energy

Question 6

name the 4 forces that comprise net filtration pressure

Answer 6

1. glomerular capillary blood pressure
2. bowman’s capsule hydrostatic (fluid) pressure
3. capillary oncotic pressure
4. bowmans capsule oncotic pressure

Question 7

how does the glomerular capillary blood pressure remain constant?

Answer 7

as afferent arteriole is wider than efferent arteriole

Question 8

state whether they are going IN or OUT of the blood vessel into the bowmans capsule:

1. glomerular capillary blood pressure
2. bowman’s capsule hydrostatic (fluid) pressure
3. capillary oncotic pressure
4. bowmans capsule oncotic pressure

Answer 8

1. glomerular capillary blood pressure - OUT
2. bowman’s capsule hydrostatic (fluid) pressure - IN
3. capillary oncotic pressure - IN
4. bowmans capsule oncotic pressure - OUT

Question 9

net filtration pressure = __ mm Hg

Answer 9

net filtration pressure = 10 mm Hg

Question 10

name the term used to balance hydrostatic and osmotic forces

Answer 10

starling forces

Question 11

rate at which protein-free plasma is filtered from the glomeruli into the Bowman’s capsule per unit time defines what?

Answer 11

GFR

Question 12

what is the major determinant of GFR?

Answer 12

glomerular capillary fluid (blood) pressure

Question 13

if you decrease GFR, you produce ____ urine

Answer 13

if you decrease GFR, you produce LESS urine

Question 14

‘normal’ GFR?

Answer 14

125ml/min

Question 15

GFR is regulated by both _________ and __________ regulations

Answer 15

GFR is regulated by both INTRINSTIC and EXTRINSIC regulations

Question 16

if afferent arteriole diameter increases (smooth muscle relaxes) what happens to GFR?

Answer 16

increases

Question 17

what is a decrease in arterial blood pressure detected by?

Answer 17

aortic and carotid-sinus baroreceptors

Question 18

fall in blood volume due to bleeding _________ blood volume

Answer 18

fall in blood volume due to bleeding REDUCES blood volume

Question 19

state the 2 parts to auto regulation (intrinsic) of kidney

Answer 19

myogenic and tubuloglomerular feedback

Question 20

tubuloglomerular feedback:

If GFR rises, more NaCl flows through the tubule leading to _____________ of afferent arterioles

Answer 20

tubuloglomerular feedback:

If GFR rises, more NaCl flows through the tubule leading to CONSTRICTION of afferent arterioles

Question 21

GFR = ? x ?

Answer 21

GFR = Kf x net filtration pressure

Question 22

increase of decrease of GFR:

(a) kidney stone
(b) diarrhoea
(c) severely burned patients
(d) change in surface area available for filtration

Answer 22

(a) kidney stone - DECREASE
(b) diarrhoea - DECREASE
(c) severely burned patients - INCREASE
(d) change in surface area available for filtration - INCREASE

Question 23

what equals the volume of plasma completely cleared of a particular substance per minute?

Answer 23

plasma clearance

Question 24

units of clearance?

Answer 24

ml/min

Question 25

clearance of substance X = ? x ? / ?

Answer 25

clearance of substance X = [X]urine x Vurine / [X]plasma

Question 26

what foods are inulin found in?

Answer 26

onions and garlic

Question 27

inulin measurement clearance can be used clinically to determine what?

Answer 27

GFR

Question 28

is inulin metabolised by the kidney?

Answer 28

no - not absorbed or secreted

Question 29

what can be measured instead of inulin?

Answer 29

creatinine

acts similar to inulin in kidney

Question 30

what substance is completely reabsorbed and not secreted?

Answer 30

glucose

Question 31

glucose clearance = ?

Answer 31

glucose clearance = 0

Question 32

what substance is partly reabsorbed and not secreted?

Answer 32

urea

Question 33

urea clearance >/< urea GFR

Answer 33

urea clearance < urea GFR

Question 34

what substance is secreted but not reabsorbed?

Answer 34

H+

Question 35

H+ clearance >/< H+ GFR

Answer 35

H+ clearance > H+ GFR

Question 36

If clearance < GFR (inulin clearance) then substance is ____________

Answer 36

If clearance < GFR (inulin clearance) then substance is REABSORBED

Question 37

If clearance ? GFR then substance is neither reabsorbed nor secreted

Answer 37

If clearance = GFR then substance is neither reabsorbed nor secreted

Question 38

If clearance > GFR then substance is __________ into tubule

Answer 38

If clearance > GFR then substance is SECRETED into tubule

Question 39

what substance is used to calculate renal plasma flow (RPF)?

Answer 39

para-amino hippuric acid (PAH)

Question 40

PAH clearance = ?

Answer 40

650ml/min

Question 41

inulin/creatinine clearance = ?

Answer 41

inulin/creatinine clearance = 125ml/min

Question 42

what should not be toxic, be inert and be easy to measure?

Answer 42

clearance marker

Question 43

A GFR marker should be filtered freely; ___ secreted or reabsorbed

Answer 43

A GFR marker should be filtered freely; NOT secreted or reabsorbed

Question 44

A RPF marker should be filtered and ___________ secreted

Answer 44

A RPF marker should be filtered and COMPLETELY secreted

Question 45

GFR = ___ ml/min

RPF = ___ ml/min

Answer 45

GFR = 125 ml/min

RPF = 650 ml/min