L7: Potassuim

Question 1

1. What is the main intracellular cation?
- a. Sodium
- b. Potassium
- c. Calcium
- d. Magnesium

Answer 1

B

Question 2

2. What is the effect of increased plasma K+ on excitability?
- a. Hyperexcitability
- b. Hypoexcitability
- c. No change in excitability
- d. Decreased osmolarity

Answer 2

A

Question 3

3. What can cause increased plasma K+ levels?
- a. Acid-base disbalance (metabolic acidosis)
- b. Plasma osmolarity
- c. Alkaline pH
- d. Hydration

Answer 3

A

Question 4

4. What happens in hypertonic plasma regarding cell osmolarity?
- a. Decreases osmolarity in the cell
- b. Increases osmolarity in the cell
- c. No effect on cell osmolarity
- d. Causes cell lysis

Answer 4

B

Question 5

5. What does hypokalemia result in?
- a. Increased membrane potential
- b. Decreased excitability
- c. Hyperkalemia
- d. Cell lysis

Answer 5

B

Question 6

6. Which tissues are highly affected by changes in potassium levels?
- a. Skeletal muscle
- b. Brain
- c. Heart
- d. Liver

Answer 6

C

Question 7

7. What is the majority of potassium found in?
- a. Extracellular fluid
- b. Blood plasma
- c. Intracellular fluid
- d. Interstitial fluid

Answer 7

C

Question 8

8. How does insulin affect potassium uptake into the cell?
- a. Inhibits K+ uptake
- b. Activates Na/K+ exchanger
- c. Decreases SA node activity
- d. Promotes cell lysis

Answer 8

B

Question 9

9. How does adrenaline prevent high plasma K+ during exercise?
- a. Inhibits skeletal muscle activity
- b. Stimulates K+ secretion
- c. Increases K+ uptake
- d. Promotes hyperkalemia

Answer 9

C

Question 10

10. Which factor protects the brain from rapid changes in potassium levels?
- a. Blood-brain barrier
- b. Cerebrospinal fluid
- c. BBB receptors
- d. Neurotransmitters

Answer 10

A

Question 11

11. What is the clinical significance of IV glucose in hyperkalemia treatment?
- a. Increases potassium secretion
- b. Induces hypokalemia
- c. Promotes potassium uptake into cells
- d. Triggers renal failure

Answer 11

C

Question 12

12. How does aldosterone respond to long-term hyperkalemia?
- a. Decreases K+ secretion
- b. Activates sodium channels
- c. Increases K+ secretion
- d. Inhibits ENaC

Answer 12

C

Question 13

13. What is the role of a-Intercalated cells in renal potassium handling?
- a. Promote potassium secretion
- b. Reabsorb potassium
- c. Secrete H+ ions
- d. Activate sodium channels

Answer 13

B

Question 14

14. How does hyperkalemia affect potassium stores in the cell?
- a. Decreases intracellular potassium
- b. Causes intracellular hyperkalemia
- c. Has no impact on intracellular stores
- d. Promotes potassium excretion

Answer 14

B

Question 15

15. What stimulates aldosterone release for potassium regulation?
- a. Low plasma sodium
- b. Low blood volume
- c. Hyperkalemia
- d. High plasma osmolarity

Answer 15

C

Question 16

16. How does ADH affect sodium reabsorption and potassium secretion?
- a. Increases both sodium reabsorption and potassium secretion
- b. Inhibits both sodium reabsorption and potassium secretion
- c. Increases sodium reabsorption, inhibits potassium secretion
- d. Has no effect on renal ion handling

Answer 16

C

Question 17

17. What factor does not change potassium levels?
- a. Body water content
- b. Diuretics use
- c. Increased tubular fluid flow
- d. Hypovolemia

Answer 17

C

Question 18

18. How does hypovolemia affect potassium handling in the kidneys?
- a. Increases K+ reabsorption
- b. Decreases K+ secretion
- c. Has no effect on K+ handling
- d. Promotes K+ excretion

Answer 18

C

Question 19

19. What is the effect of high sodium intake on potassium levels?
- a. Increases K+ secretion
- b. Decreases K+ reabsorption
- c. Decreases K+ levels
- d. Has no impact on K+ regulation

Answer 19

C

Question 20

20. How does flow rate affect potassium excretion through cilia?
- a. Decreases K+ excretion
- b. Promotes K+ secretion
- c. Has no effect on K+ excretion
- d. Induces hyperkalemia

Answer 20

C

Question 21

21. What is the primary mechanism of potassium reabsorption in the PCT (Proximal Convoluted Tubule)?
- a. Filtration
- b. Active transport
- c. Solvent drag
- d. Facilitated diffusion

Answer 21

C

Question 22

22. How is potassium reabsorbed in the TALH (Thick Ascending Limb of Henle)?
- a. Via Na/K pump
- b. Passive diffusion
- c. NKCC cotransporter
- d. Through aquaporins

Answer 22

C

Question 23

23. Which cells in the DCT (Distal Convoluted Tubule) and CT (Collecting Tubule) are involved in potassium reabsorption?
- a. Principle cells
- b. Intercalated cells
- c. Endothelial cells
- d. Epithelial cells

Answer 23

B

Question 24

24. What is the impact of renal failure on potassium secretion?
- a. Increases K+ secretion
- b. Enhances K+ reabsorption
- c. Impairs K+ secretion
- d. Promotes intracellular hyperkalemia

Answer 24

C

Question 25

**25. How does aldosterone respond to increased potassium levels?** - a. Inhibits K+ secretion - b. Activates NKCC cotransporter - c. Increases K+ secretion - d. Promotes potassium excretion

Answer 25

C

Question 26

**26. What is the role of ADH (Antidiuretic Hormone) in sodium and potassium handling?** - a. Increases both sodium reabsorption and potassium secretion - b. Inhibits both sodium reabsorption and potassium secretion - c. Increases sodium reabsorption, inhibits potassium secretion - d. Promotes sodium excretion, increases potassium secretion

Answer 26

C

Question 27

**27. Which factor does not influence potassium levels?** - a. Body water content - b. Diuretics use - c. Increased tubular fluid flow - d. Hypovolemia

Answer 27

Cc

Question 28

**28. How does high flow rate impact potassium excretion through cilia?** - a. Decreases K+ excretion - b. Promotes K+ secretion - c. Has no effect on K+ excretion - d. Induces hyperkalemia

Answer 28

C

Question 29

**29. What is the clinical significance of hyperkalemia adaptation in individuals exposed to elevated potassium levels?** - a. Increases K+ secretion - b. Enhances potassium reabsorption - c. Adapts to higher K+ levels - d. Promotes intracellular hyperkalemia

Answer 29

C

Question 30

**30. How do diuretics impact potassium homeostasis?** - a. Increase K+ secretion - b. Decrease K+ reabsorption - c. Induce hyperkalemia - d. Have no effect on K+ regulation

Answer 30

C

Question 31

**31. What is the role of aldosterone in response to long-term hyperkalemia?** - a. Decreases K+ secretion - b. Activates sodium channels - c. Increases K+ secretion - d. Inhibits ENaC

Answer 31

C

Question 32

**32. How does ADH (Antidiuretic Hormone) affect sodium and potassium handling in the kidneys?** - a. Increases both sodium reabsorption and potassium secretion - b. Inhibits both sodium reabsorption and potassium secretion - c. Increases sodium reabsorption, inhibits potassium secretion - d. Promotes sodium excretion, increases potassium secretion

Answer 32

C

Question 33

**33. Which cells in the renal tubules are involved in reabsorbing potassium through H/K ATPase?** - a. Principal cells - b. Intercalated cells - c. Endothelial cells - d. Epithelial cells

Answer 33

B

Question 34

**34. What is the effect of insulin on potassium uptake into cells?** - a. Inhibits K+ uptake - b. Activates Na/K+ exchanger - c. Decreases SA node activity - d. Promotes cell lysis

Answer 34

B

Question 35

**35. How does high sodium intake impact potassium levels?** - a. Increases K+ secretion - b. Decreases K+ reabsorption - c. Decreases K+ levels - d. Has no impact on K+ regulation

Answer 35

C

Question 36

**36. What stimulates aldosterone release for potassium regulation?** - a. Low plasma sodium - b. Low blood volume - c. Hyperkalemia - d. High plasma osmolarity

Answer 36

C

Question 37

37. What is the clinical significance of hyperkalemia adaptation in individuals exposed to elevated potassium levels?** - a. Increases K+ secretion - b. Enhances potassium reabsorption - c. Adapts to higher K+ levels - d. Promotes intracellular hyperkalemia

Answer 37

C

Question 38

*38. What happens in hypertonic plasma regarding cell osmolarity?** - a. Decreases osmolarity in the cell - b. Increases osmolarity in the cell - c. No effect on cell osmolarity - d. Causes cell lysis

Answer 38

B

Question 39

**39. How does adrenaline prevent high plasma K+ during exercise?** - a. Inhibits skeletal muscle activity - b. Stimulates K+ secretion - c. Increases K+ uptake - d. Promotes hyperkalemia

Answer 39

C

Question 40

*40. What is the clinical significance of IV glucose in hyperkalemia treatment?** - a. Increases potassium secretion - b. Induces hypokalemia - c. Promotes potassium uptake into cells - d. Triggers renal failure

Answer 40

C

Question 41

**41. How does acid-base imbalance contribute to increased plasma K+?** - a. Decreases K+ levels - b. Increases K+ levels - c. Has no effect on K+ - d. Promotes intracellular hyperkalemia

Answer 41

B

Question 42

**42. In hypertonic plasma, what happens to cell osmolarity and K+ movement?** - a. Decreases osmolarity; K+ moves into the cell - b. Increases osmolarity; K+ moves into the cell - c. No effect on osmolarity; K+ moves out of the cell - d. Causes cell lysis; K+ remains unchanged

Answer 42

B

Question 43

**43. What is the primary effect of insulin on potassium uptake?** - a. Inhibits potassium uptake - b. Activates Na/K+ exchanger - c. Promotes cell lysis - d. Increases SA node activity

Answer 43

B

Question 44

**44. How does increased flow rate impact potassium excretion through cilia?** - a. Decreases K+ excretion - b. Promotes K+ secretion - c. Has no effect on K+ excretion - d. Induces hyperkalemia

Answer 44

C

Question 45

**45. What tissues are highly affected by changes in potassium levels?** - a. Skeletal muscle and liver - b. Heart and brain - c. Kidneys and lungs - d. Skin and pancreas

Answer 45

B

Question 46

**46. What is the major intracellular cation?** - a. Sodium - b. Potassium - c. Calcium - d. Magnesium

Answer 46

B

Question 47

**47. How does hypovolemia impact potassium handling in the kidneys?** - a. Increases K+ secretion - b. Decreases K+ reabsorption - c. Has no effect on K+ handling - d. Promotes K+ excretion

Answer 47

C

Question 48

**48. What is the role of ADH in potassium secretion?** - a. Inhibits potassium secretion - b. Activates sodium channels - c. Stimulates potassium secretion - d. Promotes intracellular hyperkalemia

Answer 48

C

Question 49

**49. How does hyperkalemia impact intracellular potassium levels?** - a. Decreases intracellular potassium - b. Causes intracellular hyperkalemia - c. Has no impact on intracellular stores - d. Promotes potassium excretion

Answer 49

B

Question 50

**50. What is the primary factor affecting potassium homeostasis during diuresis?** - a. Decreased ADH levels - b. Increased sodium reabsorption - c. Potassium reabsorption - d. Hyperkalemia induction

Answer 50

C

Question 51

**51. How does increased cilia bending impact potassium excretion through the renal tubules?** - a. Decreases K+ excretion - b. Promotes K+ secretion - c. Has no effect on K+ excretion - d. Induces hyperkalemia

Answer 51

C

Question 52

**52. What is the primary role of BK (Maxi) channels in potassium secretion?** - a. Flow-dependent secretion - b. Constitutive secretion - c. Sequestered secretion - d. Sodium reabsorption

Answer 52

C

Question 53

**53. What stimulates the opening of BK channels in the renal tubules?** - a. Increased sodium levels - b. Calcium entry or partial depolarization - c. Decreased flow rate - d. Inhibition by aldosterone

Answer 53

B

Question 54

**54. How does hypokalemia affect membrane potential and cell excitability?** - a. Increases membrane potential - b. Decreases excitability - c. Has no impact on membrane potential - d. Promotes hyperexcitability

Answer 54

B

Question 55

**55. What is the main effect of increased sodium intake on potassium levels?** - a. Increases K+ secretion - b. Decreases K+ reabsorption - c. Decreases K+ levels - d. Has no impact on K+ regulation

Answer 55

C

Question 56

**56. How does increased tubular fluid flow affect potassium handling in the renal tubules?** - a. Increases K+ secretion - b. Decreases K+ reabsorption - c. Has no effect on K+ handling - d. Promotes K+ excretion

Answer 56

C

Question 57

**57. What stimulates aldosterone release to regulate potassium levels?** - a. Low plasma sodium - b. Low blood volume - c. Hyperkalemia (Answer) - d. High plasma osmolarity

Answer 57

C

Question 58

**58. How does insulin impact potassium uptake into cells?** - a. Inhibits potassium uptake - b. Activates Na/K+ exchanger - c. Decreases SA node activity - d. Promotes cell lysis

Answer 58

B

Question 59

**59. What tissues are less affected by changes in potassium levels?** - a. Heart and brain - b. Skeletal muscle and liver - c. Skeletal muscle and lungs - d. Skeletal muscle and kidneys

Answer 59

D

Question 60

**60. What is the primary mechanism of potassium reabsorption in the PCT (Proximal Convoluted Tubule)?** - a. Filtration - b. Active transport - c. Solvent drag - d. Facilitated diffusion

Answer 60

C