Physiology

Question 1

What’s the major sites of H20 reabsorption in the GI tract? (in descending order)

Answer 1

in descending order: jejunum, ileum, colon

Question 2

What’s the most effective nephron site for acid excretion

Answer 2

proximal tubule of the kidney

Question 3

Where in the nephron does ADH act?

Answer 3

Collecting duct

Question 4

Where in the nephron is the greatest amount of free water generated?

Answer 4

thick ascending limb in the MEDULLA

Question 5

What happens when the thorax is compressed under water?

Answer 5

Produces a restrictive pattern on PFTs

Question 6

What happens to GFR and renal plasma flow if the efferent arteriole is constricted?

Answer 6

increases the GFR and decreases renal plasma flow

Question 7

Starling equation for GFR ml/min

Answer 7

GFR = Kf [(Pgc-Pbs)-PIgc]

Question 8

Kf = ? in the Starling equation?

Answer 8

hydraulic conductance in ml/min.mmHg or filtration coefficient

Question 9

Pgc = ? in the Starling equation?

1. What happens if efferent arteriole is constricted?
2. What happens if afferent arteriole is constricted?

Answer 9

hydrostatic pressure in the glomerular capillary in mmHG
pushes fluid out of the capillary
1. increases
2. decreases

Question 10

Pbs = ? in the Starling equation?

Answer 10

hydrostatic pressure in bowman’s space in mmHg

pushes fluid into the capillary

Question 11

PIgc = ? in the starling equation?

Answer 11

the oncotic pressure in the glomerular capillary in mmHg

Brings fluid back into the capillary

Question 12

Net filtration = ?

Answer 12

sum of Pbs, Pgc and PIgc in the starling equation

Question 13

what starling force changes to produce a net ultrafiltration of zero?

Answer 13

PIgc - becomes increased
- pulls fluid back into the glomerular capillary

it is the only factor that doesnt remain constant along the length of the capillary due to differences in protein concentration

Question 14

Filtration fraction in the glomerulus
FF = GFR/RPF
RPF = renal plasma flow
what happens if you:
1.  constrict afferent arteriole?
2. constrict efferent arteriole?
3. increase plasma protein conc?
4. dec plasma protein conc?
5. constrict the ureter

Answer 14

1. no change in FF (dec in GFR and RPF)
2. Inc FF (inc GFR much more than RPF)
3. inc PIgc –> dec GFR w/no change in RPF –> dec FF
4. dec PIgc –> GFR w/no change in RPF –> inc FF
5. inc PBS –> dec GFR w/no change in RPF –> dec FF

Question 15

What causes the negative charge of the GBM?

Answer 15

heparin sulfate

Question 16

S1 heart sound correlates with ___ wave in teh jugular venous pulses

Answer 16

C

C wave is closure of the tricuspid valve

Question 17

What does a carotid massage do?

Answer 17

decreases HR and inc vasodilation (carotid sinus baroreceptor is innervated by the IX and Xth CN; impulses generated in this receptor inhibit tonic discharge of the vasoconstrictor nerves and excite vagal innervation of the heart producing vasodilatation, venodilation, drop in BP and HR, and dec in CO.