Renal 4: Salt Balance

Question 1

the kdneys match salt out to salt ___

Answer 1

in

Question 2

____ is the main determinant of extracellular fluid volume

Answer 2

na

Question 3

Na reabsorption is regulated by the ____ system of hormones; by ____ and also by ____ nervous system activity

Answer 3

renin-angiotensin; ANP; sympathetic

Question 4

increased Na / blood volume causes a ___ in Na excretion

Answer 4

increase

Question 5

decreased Na / blood volume causes a ___ in Na excretion

Answer 5

decrease

Question 6

Na reabsorption is inhibited by ___ drugs that are used to reduce BP

Answer 6

diuretic

Question 7

the kidneys match K excretion to K ___

Answer 7

intake

Question 8

K can be secreted by ___ parts of the nephron to allow control of body K homeostasis

Answer 8

distal

Question 9

K secretion is regulated by plasma ___ and the hormone ___

Answer 9

K concentration; aldosterone

Question 10

as Na increases, the extracellular fluid volume __

Answer 10

increases

Question 11

what is the effect of the renin-angiotensin-aldosterone system on Na reabsorption and excretion?

Answer 11

increase reabs ; decrease excretion

Question 12

what is the effect of ANP on the reabsorption and excretion of Na>

Answer 12

decrease reabsorption; increase excretion

Question 13

what is the effect of sympathetic activity on Na excretion?

Answer 13

decreases GFR by constricting BV; lowers excretion

Question 14

decribe the pathway of the renin-angiotensin-aldosterone system

Answer 14

low na –> low ECF volume –> release of renin / formation of angiotensin 2 –> aldosterone –> increase Na and water reabsorption –> increased ECF volume

Question 15

angiotensin 2 ____ (directly or indirectly) increases Na reabsorption in the nephron

Answer 15

directly

Question 16

angiotensin 2 acts on ___ receptors of tubular epithelial cells

Answer 16

AT1

Question 17

angiotensin 2 increases the activity of ___

Answer 17

Na transport proteins

Question 18

angiotensin 2 stimulates the secretion of ___ from the adrenal gland

Answer 18

aldosterone

Question 19

aldosterone increases the activity of apical ___ channels in the collecting duct and also increases the ___ of ENaC and Na/K pump

Answer 19

ENac Na; genetic expression

Question 20

aldosterone ___ the reabsorption of Na

Answer 20

increases

Question 21

describe the pathway of ANP

Answer 21

high sodium –> high ECF volume –> release of ANP –> decrease Na and water reabs –> decreased ECF

Question 22

ANP is the antagonist to ___

Answer 22

aldosterone

Question 23

ANP is released from the

Answer 23

heart

Question 24

diuretic drugs act on the ____ to ___ Na reabsorption

Answer 24

renal tubular Na transport proteins; reduce

Question 25

how much more urine does a person produce when on diuretics?

Answer 25

very little, because the Na out will be matched to Na in

Question 26

loop diuretics act on what transport proteins? where?

Answer 26

NKCC; loop of henle

Question 27

thiazide diuretics act on what transport proteins? where?

Answer 27

NCC; distal tubule

Question 28

K sparing diuretics act what transport proteins? where?

Answer 28

ENaC; late distal tubule and collecting duct

Question 29

what are 2 ENaC channel mutations?

Answer 29

1. Pseudohypoaldosteronism | 2. liddle's syndrome

Question 30

what happens in pseudohypoaldosteronism?

Answer 30

loss of ENaC function, more Na excretion, reduced ECF, hypotension

Question 31

what happens in liddle's syndrome?

Answer 31

excessive ENaC function, decreased Na excretion, raised ECF, hypertension

Question 32

K homeostais must be maintained within a very ___ rnage

Answer 32

narrow

Question 33

t/f a small rise in K in the plasma can be fatal

Answer 33

t

Question 34

K homeostasis is controlled by the ___

Answer 34

kidneys

Question 35

K excretion is highly __

Answer 35

variable

Question 36

K secretion is regulated by what hormone?

Answer 36

aldosterone

Question 37

1% excretion of K in cases of ___

Answer 37

hypokalemia

Question 38

100% excretion of K in cases of ___

Answer 38

hyperkalemia

Question 39

depending on the K concentration, the distal tubule is capable of either ___ or ___

Answer 39

K reabsorption or K secretion

Question 40

____ cells in the ____ and ___ parts of the nephron secrete K

Answer 40

principal; late distal tube and collecting duct

Question 41

____ cells in the ____ and ____ parts of the nephron reabsorb K

Answer 41

intercalated; late distal tube and collecting duct

Question 42

how is K absorbed by intercalated?

Answer 42

H/K atpase pump in apical membrane

Question 43

how is K secreted by principle cells?

Answer 43

K channels

Question 44

what happens in a principle cell when plasma K is incresed?

Answer 44

Na/K pump on baso side bring K in then out on apical end by K channels, aldosterone in secreted by the adrenal cortex

Question 45

aldosterone increases the expression of __ and ___ and the permeability of K on the ___ end of the principle cells

Answer 45

Na/K pump on baso; ENac channels; apical