Ion and Hormone Regulation

Question 1

When is ANP (atrial natriuretic peptide) released?

Answer 1

As a result of stretch receptors in the cardiac aorta

Question 2

What effect does ANP have on GFR and tubular reabsorption of sodium?

Answer 2

Increased GFR

Decreased tubular reabsorption of sodium

Question 3

What is the first line of defense for the regulation of potassium balance?

Answer 3

Insulin (uptake of potassium into cells after meal)

Question 4

What are potassium levels like with a person who has diabetes?

Answer 4

High (hyperkalemia)

Question 5

What effect does increased potassium have on aldosterone production?

Answer 5

Stimulation of cellular uptake of potassium

Question 6

What is the condition of excess aldosterone in the system?

Answer 6

Conn’s syndrome (hypokalemia)

Question 7

What is the condition of deficient aldosterone?

Answer 7

Addison’s disease (hyperkalemia)

Question 8

Increased secretion of what specific catecholamine increases the movement of potassium into cells?

Answer 8

Epinephrine

Question 9

B-adrenergic receptor blockers treat what condition by increasing movement of potassium out of the cells?

Answer 9

Hypertension

Question 10

What other issue can result from the use of B-adrenergic receptor blockers as treatment for hypertension?

Answer 10

Hyperkalemia

Question 11

What effect does metabolic acidosis have on potassium balance?

Answer 11

Loss of potassium from cells (increased extracellular K+ levels)

Question 12

What effect does metabolic alkalosis have on potassium balance?

Answer 12

Movement of potassium into cells (decreased extracellular K+ levels)

Question 13

During which situation is the activity of the ATPase pump REDUCED? Hyperactive?

Answer 13

Reduced - metabolic acidosis

Hyperactive - metabolic alkalosis

Question 14

What happens to the potassium balance during cell lysis?

Answer 14

Potassium released to extracellular compartment (severe hyperkalemia)

Question 15

What effect can prolonged and strenous exercise have on potassium balance?

Answer 15

Release of potassium from muscles (hyperkalemia)

Question 16

When can hyperkalemia via strenuous exercise become severe?

Answer 16

In person is on B-androgenic blocker or has insulin deficiency

Question 17

What are the factors that shift potassium INTO the cell?

Answer 17

Insulin, aldosterone, B-adrenergic stimulation, alkalosis, decreased extracellular fluid osmolarity

Question 18

What are the factors that shit potassium OUT of the cell?

Answer 18

Insulin deficiency, aldosterone deficiency, B-adrenergic blockers, acidosis, cell lysis, strenuous exercise, increased extracellular fluid osmolarity

Question 19

What effect does aldosterone have on the potassium permeability of the luminal membrane?

Answer 19

Increase

Question 20

Where is half of the calcium in the blood plasma located?

Answer 20

Bound to proteins (so only half is available to filter out at glomerulus)

Question 21

Where is the majority of calcium reabsorbed?

Answer 21

Proximal tubule

Question 22

What hormone is the major regulator of calcium in the renal system?

Answer 22

Parathyroid hormone (PTH)

Question 23

Where is reabsorption of calcium unaffected by PTH?

Answer 23

Proximal tubule

Question 24

Where is reabsorption of calcium affected by PTH?

Answer 24

Loop of Henle and distal tubule

Question 25

Which involves a state of increased reabsorption of hydrogen ions: alkalosis or acidosis?

Answer 25

Alkalosis

Question 26

Which involves a state of decreased reabsorption of hydrogen ions: alkalosis or acidosis?

Answer 26

Acidosis

Question 27

What factors stimulate calcium excretion?

Answer 27

Decreased PTH, increased ECF volume, increased BP, Increased H+ concentration (acidosis)

Question 28

What factors decreased calcium excretion?

Answer 28

Increased PTH, decreased ECF volume, decreased BP, decreased H+ concentration (alkalosis)

Question 29

Only about how much typical magnesium intake is absorbed by the digestive system?

Answer 29

50% (more than needed for daily function)

Question 30

Where does the majority of phosphate reabsorption occur?

Answer 30

Proximal tubule

Question 31

At what pH is one considered to have acidosis?

Answer 31

Below 7.4

Question 32

At what pH is one considered to have alkalosis?

Answer 32

Above 7.4

Question 33

What are the three systems in which the body defends itself against changes in hydrogen ion concentration?

Answer 33

Acid-base buffering system of fluids Respiratory center Kidneys

Question 34

How long does it take the acid-base buffering system to react to a shift in hydrogen concentration?

Answer 34

Seconds

Question 35

How long does it take the respiratory center to react to a shift in hydrogen concentration?

Answer 35

Minutes

Question 36

A condition like emphysema that decreases the ability of the lungs to eliminate CO2 can lead to what situation: acidosis or alkalosis?

Answer 36

Acidosis

Question 37

How long does it take for the kidneys to react to a state of acid-base imbalance?

Answer 37

Hours to days

Question 38

What are the most powerful regulators in the acid-base regulation system?

Answer 38

Kidneys (even though they're the slowest)

Question 39

How do the kidneys control acid-base regulation (hydrogen ion concentration)?

Answer 39

Excreting acidic or basic urine

Question 40

How do the kidneys regulate extracellular fluid hydrogen ion concentration?

Answer 40

Secretion of hydrogen ions Reabsorption of filtered HCO3- Production of new HCO3-

Question 41

Where do hydrogen ion secretion and HCO3- occur?

Answer 41

All parts of the tubule EXCEPT the thin ascending and thin descending limb of the loop of Henle

Question 42

What is the primary reason for stimulation of hydrogen ion secretion by the renal tubules?

Answer 42

Acidosis or alkalosis of the body

Question 43

What is the condition where acidosis occurs due to an increase in partial pressure of CO2?

Answer 43

Respiratory acidosis

Question 44

What is the condition where acidosis occurs due to a fall in HCO3-?

Answer 44

Metabolic acidosis

Question 45

When does gluconeogensis occur in the kidneys?

Answer 45

During periods of prolonged fasting

Question 46

What amino acids are primarily used by the kidneys during gluconeogenesis?

Answer 46

Lactate, glutamine, and glycerol

Question 47

What conditions stimulate gluconeogenesis?

Answer 47

Low carb levels in cells and in blood plasma

Question 48

Low carb levels trigger the secretion of what substance during gluconeogenesis?

Answer 48

Corticotropin

Question 49

What major hormone is produced in response to corticotropin in gluconeogenesis?

Answer 49

Cortisol

Question 50

What is the purpose of cortisol during gluconeogenesis?

Answer 50

Mobilizes proteins for movement and use