Renal Physio

Front 1

what is a normal glomerular filtration rate?

Back 1

120-130 ml/min

Front 2

What is a normal filtration fraction?

Back 2

20%

Front 3

what is a normal renal blood flow?

Back 3

1 L/min (20-25% of cardiac output)

Front 4

what is a normal renal plasma flow?

Back 4

650 ml/min

Front 5

What are the three layers of the filtration barrier?

Back 5

1) fenestrated endothelium of glomerular capillary
2) shared basement membrane
3) podocytes of Bowman's capsule

Front 6

The pores between the foot processes of the podocytes in the filtration barrier are closed by a thin membrane called what?

Back 6

slit diaphragm

Front 7

What part of the filtration barrier is teh primary site of permselectivity, the main size selective filter?

Back 7

slit diaphragm

Front 8

The slit pores between podocytes of the filatration barrier are joined in a zipper like fashion by what proteins?

Back 8

occludins

Front 9

What is the equation for the sieving coefficient?

Back 9

=concentration of ultrafiltrate (urine)/concentration in plasma

Front 10

Is a substance with a sieving coefficient of 1 easily filtered or not filtered at all?

Back 10

easily filtered

Front 11

The glomerular basement membrane has a cationic/anionic quality

Back 11

anionic

Front 12

There is no albumin found in urine, yet a very small amount of it is filtered by the glomerulus. explain this finding

Back 12

albumin is reabsorbed in the proximal tubule by endoytosis

Front 13

GFR ceases at what blood pressure value?

Back 13

40 to 50 mm Hg

Front 14

The JG apparatus responds to an increase in NaCl within the range of:

Back 14

20-80 mM

Front 15

The JGA apparatus causes two events that will decrease blood pressure. what are they?

Back 15

aferent arteriolar vasoconstriction and decrease rate of renin secretion

Front 16

High NaCl is sensed by cells in the macula densa via what transporter?

Back 16

NKCC2 (Na,K, 2Cl)

Front 17

What hormone is the mediator in tubuloglomerular feedback?

Back 17

adenosine

Front 18

What is the effect of the TGF mechanism in response to low NaCl concentrations? what if these low concentrations are sustained?

Back 18

immediately, the TGF will cause a lesser release of adenosine, causing afferent arteriole dilation. but over sustained low NaCl concentrations the macula densa will cause release of renin and this afferent arteriole constriction.

Front 19

what does the macula densa secrete thats responsible for renin release?

Back 19

prostoglandin E2

Front 20

How does an increase in afferent arteriole resistance effect RPF, GFR, and FF?

Back 20

decreases all of them

Front 21

how does a small increase in efferent arteriole resistance effect GFR?

Back 21

small increase due to rise in hydrostatic pressure

Front 22

how does a increase in efferent arteriole resistance effect GFR?

Back 22

decreases GFR

Front 23

Prostaglandins are synthesized from what?

Back 23

arachidonic acid

Front 24

Prostaglandins ten to cause compensatory vasoconstriction/vasodilation?

Back 24

vasodilation

Front 25

Thromboxane and endothelin are important vasoconstrictors/vasodilators?

Back 25

vasoconstrictors

Front 26

GFR=

Back 26

125 mL/min

Front 27

fractional excretion=

Back 27

clearance X/clearance inulin

Front 28

what percent of Na+ is reabsorbed in the proximal tubule?

Back 28

2/3

Front 29

What percent of bicarbonate is reabsorbed in the proximal tubule?

Back 29

90%

Front 30

What percent of glucose and amino acids are absorbed in the proximal tubule?

Back 30

100%

Front 31

What percent of water is reabsorbed in the proximal tubule?

Back 31

2/3 (66%)

Front 32

Is PAH actively reabsorbed, secreted, or neither?

Back 32

secreted

Front 33

What enzyme is important in the reabsorbing of bicarbonate?

Back 33

carbonic anhydrase

Front 34

The passive reabsorption of urea is dependent on ______

Back 34

urine flow rate

Front 35

What transporter is responsible for 90& of glucose reabsorption i the PCT?

Back 35

SGLT2

Front 36

Parathyroid hormone will cause absorption/excretion of phosphate?

Back 36

excretion

Front 37

PAH can be used to determine renal function only under ____ mg/dL. why?

Back 37

20. because after that you have reached Tm and excretion is driven purely by filtration

Front 38

If the GFR increase, will more sodium be reabsorbed or excreted?

Back 38

reabsorbed

Front 39

What percent of potassium is reabsorbed in the PCT? phosphate?

Back 39

80%; 80%

Front 40

What is leaving the tubular fluid in the thin descending limb of the loop of henle?

Back 40

water

Front 41

What is the movement of molucuels in the thin ascending limb?

Back 41

sodium leaving

Front 42

How does sodium get reabsorbed in the TAL?

Back 42

KaK2Cl transporter

Front 43

How does furosemide work?

Back 43

loop diuretic, blocks NaK2Cl transporter

Front 44

How is potassium handled in the TAL?

Back 44

enters cells by NaK2Cl transporter, but can exit either basolateral or lumenal membrane

Front 45

How does sodium get reabsorbed in the early DCT?

Back 45

Na-Cl cotransporter

Front 46

How does thiazide work?

Back 46

messes up Na-Cl cotransporter (DCT)

Front 47

How does sodium get reabsorbed in the collecting tubule?

Back 47

ENaC channels

Front 48

How does amiloride and trimterene work?

Back 48

blocking ENaC

Front 49

How does acetazolamide work?

Back 49

blocks carbonic anhydrase

Front 50

How does aldosterone effect sodium, potassium, and hydrogen ions?

Back 50

Increase sodium reabsorption, increase hydrogen and potassium excretion

Front 51

What are the potassium sparing diuretics?

Back 51

amiloride, triamterene, and spirolactones

Front 52

What two molecules create the osmotic gradient in the medulla?

Back 52

sodium 50% and urea 50%

Front 53

ADH increase/decreases urea transporters in the CD?

Back 53

increases

Front 54

ADH acts on ____ cells in collecting tubules, via_______ which opens channels in tubules called _______, facilitating water absorption

Back 54

principal, adenylate cyclase, aquaporins

Front 55

what is the normal serum value of sodium?

Back 55

135-145 mEg/L

Front 56

ADH increases water reabsorption by what three mechanisms?

Back 56

Increasing aquaporins in CT, increase permeability of CD in medulla to urea, increase activity of NaK2Cl transporter in loop

Front 57

Angiotension II increase/decreases ADH secretion.

Back 57

increases

Front 58

Alcohol increases/decreases ADH secretion.

Back 58

decreases

Front 59

ANP increase/decreases ADH secretion

Back 59

decreases

Front 60

ADH binds to what receptor which will activate Gprotein and adenylene cyclase?

Back 60

V2

Front 61

What is normal urine osmolality?

Back 61

400-500 mM

Front 62

What cells produce renin?

Back 62

granular cells

Front 63

When there is a decrease in calcium, there will be an increase/decrease in renin release.

Back 63

increase

Front 64

An increase in sympathetic activity would cause an increase/decrease in renin release.

Back 64

increase

Front 65

What does bradykinin do?

Back 65

dilates blood vessels, lowering BP

Front 66

alpha adrenergic receptors vasoconstrict afferent or efferent artiroles more?

Back 66

afferent

Front 67

acidosis will cause potassium to enter/exit the cell.

Back 67

exit

Front 68

insulin, epinephrine, and aldosterone increase/decrease potassium uptake in the cell.

Back 68

increase

Front 69

What are the osmoreceptors and what are they sensitive to?

Back 69

AV3V, OVLT, SFO; AT II

Front 70

When there is an increase in osmolality, how do osmoreceptor cells detect it?

Back 70

there are cation channels on the membrane that are inactivated by the stretch caused by the cell shrinkage, the resulting depolarization produces an action potential

Front 71

Activation of osmoreceptors will have what two consequences?

Back 71

increased secretion of ADH and thirst

Front 72

Endothelin-1 is released from what? what does it do?

Back 72

posterior pituitary, increases plasma ADH levels

Front 73

How do you excrete most of your calcium?

Back 73

feces

Front 74

What does calbidin do?

Back 74

binds calcium in teh DCT cells so there is a gradient for passive entry of calcium from the lumen

Front 75

How does calcium get from the distal convoluted cells to the blood?

Back 75

calcium sodium transporter

Front 76

What are calbindin levels controlled by?

Back 76

calcitriol (Vit D3)

Front 77

Whats a normal body pH? between what pHs can humans live?

Back 77

7.4; 6.8-8

Front 78

Where does the greatest pH drop in urine occur?

Back 78

collecting duct

Front 79

What is the titratable acid?

Back 79

H2PO4-

Front 80

Which can diffuse across the cell membrane, ammonium or ammonia?

Back 80

ammonia

Front 81

What is a volitile acid?

Back 81

any acid from CO2

Front 82

What is your most important intracellular buffer system?

Back 82

phosphate

Front 83

What is the ratio of acid to bicarbonate?

Back 83

1:20

Front 84

WIll hyperkalemia increase or decrease acid secretion?

Back 84

decrease