Lecture 59 - Regulation of electrolytes by renal tubules

Question 1

what role of the kidneys oversees reabsorption of Na+, K+, Cl-, and Ca2+

Answer 1

controlling electrolyte concentrations

Question 2

what is the primary determinant of osmolality and volume in ICF/ECF

Answer 2

sodium

Question 3

the majority of ATP used in active transport contributes to

Answer 3

reabsorption of sodium

Question 4

T/F: reabsorption of sodium occurs everywhere in the kidneys

Answer 4

FALSE - not the descending loop of henle

Question 5

the higher the GFR, the ____ electrolytes in ultrafiltrate

Answer 5

more

Question 6

summarize what happens when Na+ and Cl- are increased in ultrafiltrate

Answer 6

1. macula densa senses NaCl
2. macula densa release ATP
3. constricts afferent arteriole

Question 7

what are the clinical effects of sodium imbalance

Answer 7

1. change in cell size
2. cause neurological signs

Question 8

hyponatremia

Answer 8

• sodium loss or increased free water
• cells swell causing cerebral edema

Question 9

hypernatremia

Answer 9

• excess sodium or free water loss
• cells shrink and can cause intracranial bleeding

Question 10

describe how the factor will affect sodium excretion/reabsorption:

increased GFR

Answer 10

increased Na+ in ultrafiltrate

Question 11

describe how the factor will affect sodium excretion/reabsorption:

aldosterone

Answer 11

sodium reabsorption in DCT and collecting duct

Question 12

describe how the factor will affect sodium excretion/reabsorption:

angiotensin II

Answer 12

increased reabsorption in proximal tubule

Question 13

describe how the factor will affect sodium excretion/reabsorption:

ANP (atrial natriuretic peptide)

Answer 13

increases GFR
decreases sodium, reabsorption in DCT and collecting ducts

Question 14

describe how the factor will affect sodium excretion/reabsorption:

pH

Answer 14

Na+ reabsorbed when H+ excreted

Question 15

which of the following causes a DECREASE in sodium reabsorption from the ultrafiltrate

a. aldosterone
b. agiotensin II
c. atrial natriuretic peptide

Answer 15

c. atrial natriuretic peptide

Question 16

plasma concentrations are changed by

Answer 16

1. shift K+ transcellularly
2. excretion via kidneys

Question 17

what is a major intracellular cation

Answer 17

potassium

Question 18

K+ out of cells results in

Answer 18

1. hypokalemia
2. cell repture
3. acidemia

Question 19

K+ into cells results in

Answer 19

1. hyperkalemia
2. insulin production
3. alkalemia
4. B2-agonist

Question 20

T/F: hyperkalemia is rare with normal renal function

Answer 20

TRUE

Question 21

how does hypodadrenocorticism (low aldosterone) affect potassium

Answer 21

hyperkalemia and hyponatremia

Question 22

what causes there to be hyperkalemic periodic paralysis in quarter horses

Answer 22

autosomal dominant mutations in sodium channels

Question 23

how does aldosterone affect potassium

Answer 23

enhances K+ excretion

Question 24

hyperkalemia causes

Answer 24

mild = muscle weakness and tremoring

severe = cardiac arrhythmias and arrest

Question 25

hypokalemia causes

Answer 25

nonspecific signs malaise and muscle weakness depression and seizures arrhythmias

Question 26

describe calcium ion filtration

Answer 26

reabsorption down chemical and electrical gradient but transporters needed in distal tubule

Question 27

you are treating a calf with diarrhea. a venous blood gas shows hypokalemia and acidosis. what do you predict will happen to the blood potassium concentration as the acidosis is corrected?

Answer 27

blood potassium will decrease