Renal Phys ML: 9

Question 1

What is the intracellular concentration of K+

Answer 1

150mM

Question 2

How is the intracellular concentration of K+ controlled?

Answer 2

through the Na/K ATPase pump

Question 3

What is the extracellular K+ concentration?

Answer 3

5mM

Question 4

How is the extracellular concentration of K+ controlled

Answer 4

by the kidneys

Question 5

What can small changed in K+ concentration cause?

Answer 5

lethal malfunction of excitable tissues

Question 6

What is hypokalmia

Answer 6

low K

Question 7

What is hyperkalemia

Answer 7

high K+

Question 8

Why is the resting mV lower with hypokalemia

Answer 8

lower ECF K+ concentration so it makes the gradient bigger and when K+ moves out more negative ions on membrane which makes the membrane more negative

Question 9

Why is the resting mV higher with hyperkalemia

Answer 9

higher ecf K+ concentration so it makes the gradient smaller and so when K+ moves out of the cell there is less negative ions on membrane so it becomes more positive (depolled cell at rest)

Question 10

What renal processes does K+ experience?

Answer 10

All 3:
- filtration
-reabsorption
-secretion

Question 11

How is K+ reabsorbed

Answer 11

by the paracellular route
- K+ follows water which follows Na+

Question 12

Where is K+ 65% reabsorbed and non regulated

Answer 12

in the proximal tubule

Question 13

Where is K+ reabsorbed

Answer 13

proximal tubule and ascending limb

Question 14

What regulates K+ secretion

Answer 14

aldosterone because it builds pumps and channels

Question 15

What is the major function of the glomerulus/bowman’s capsule?

Answer 15

forms ultrafiltrate of plasma

Question 16

What are the controlling forces of the glomerulus/bowman’s capsule?

Answer 16

starling forces

Question 17

What are the major functions of the proximal tubule

Answer 17

-bulk reabsorption of solutes and water
-secretion of solutes (except K+) and organic acids and bases

Question 18

What are the controlling factors of the proximal tubule

Answer 18

active transport of solutes with passive water reabsorption

Question 19

Loop of henle functions

Answer 19

establsihed medullary osmotic gradient and secretion of urea

Question 20

Descending limb function

Answer 20

bulk reabsorption of water

Question 21

Descending limb controlling factor

Answer 21

passive water reabsorption

Question 22

Ascending Limb function

Answer 22

reabsorption of Na+ and Cl-

Question 23

Ascending limb controlling factor

Answer 23

active transport driving reabsorption by cotransport

Question 24

Cortical collecting duct function

Answer 24

fine tuning of the reabsorption/secretion of small quantities of useful solutes remaining

Question 25

Cortical collecting duct controlling factor

Answer 25

aldosterone stimulates Na+ reabsorption and K+ secretion

Question 26

Cortical and medullary collecting ducts function

Answer 26

fine tuning of water reabsorption and reabsorpton of urea

Question 27

Cortical and medullary collecting ducts controlling factor

Answer 27

vasopressin increases passive reabsorption of water