Acid/Base

Question 1

Acidosis has what effect on the CNS?

Answer 1

neurons

become less excitable and CNS depression results

Question 2

Alkalosis has what effect on the CNS?

Answer 2

neurons
become hyperexcitable, firing action potentials at the slightest
signal leading to numbness or tingling, then as muscle twitches (tetanus)

Question 3

Example of buffers in the ECF

Answer 3

HCO3 (bicarb)

Question 4

Example of buffers in cells

Answer 4

Proteins, hemoglobin and phosphate

Question 5

Examples of buffers in the urine

Answer 5

phosphates

Question 6

Examples of H+ compounds from the diet and metabolism

Answer 6

Diet: Fatty acids, Amino acids

Metabolism: CO2, lactic acid, ketoacids

Question 7

What is the most acidic urine kidneys can excrete

Answer 7

a pH of 4 to 4.5

Question 8

How does H+ secretion aid in the reabsorption of HCO3

Answer 8

when H+ is secreted, it combines with filtered HCO3 in the renal tubule and forms CO2 which then diffuses into the renal tubule cells then is converted to H= and HCO3 through carbonic anhydrase

Question 9

Primary factors/ compounds that cause increased secretion of H+

Answer 9

Decrease in ECF [HCO3-] (↓pH)

Increase in arterial PCO2

Cortisol

Endothelin

Question 10

Secondary factors/ compounds that cause increased secretion of H+

Answer 10

Increase in the filtered load of HCO3-

ECF volume contraction

Angiotensin II

Aldosterone

Hypokalemia

PTH (chronic)

Question 11

Primary factors/ compounds that cause decreased secretion of H+

Answer 11

Increase in ECF [HCO3-] (↑pH)

Decrease in arterial PCO2

Question 12

Secondary factors/ compounds that cause decreased secretion of H+

Answer 12

Decrease in the filtered load of HCO3-

ECF volume expansion

Hypoaldosteronism

Hyperkalemia

PTH (acute)

Question 13

Which amino acid is metabolized to form NH3 inside renal tubular cells

Answer 13

Glutamine

Question 14

Alpha ketoglutarate is a metabolic by product from glutamine that will form which compound to be reabsorbed

Answer 14

HCO3 (bicarb)

Question 15

How would hyperkalemia cause a decrease in H+ secretion

Answer 15

When there is a higher concentration of K+ in the the blood there will be less reabsorption of K+, there less K+ available for the K+/H+ transporter resulting in a decrease in H+ secreted

Question 16

Which cells are responsible for H+ secretion during acidosis

Answer 16

Type A intercalated cells

Question 17

Which cells are responsible for HCO3 secretion during alkalosis

Answer 17

Type B intercalated cells

Question 18

During acidosis which transporters are activated and which one is inactivated

Answer 18

H+, K+-ATPase is activated and Na+,K+-ATPase is

inhibited

Question 19

During acidosis, RAAS system is activated to release aldosterone.

How does this help?

Answer 19

Aldosterone will cause an upregulation of K+ channels and reactivation of Na+/K+ channels which allows more K+ to leave the cells and more HCO3 to be reabsorbed (cotransport with Na)

Question 20

Which portion of the nephron reabsorbs most filtered bicarbonate and produces & secretes ammonium

Answer 20

proximal tubule

Question 21

Which portion of the nephron reabsorbs second largest fraction of filtered bicarbonate

Answer 21

thick ascending limb

Question 22

Which portion of the nephron:
Reabsorbs virtually all remaining filtered bicarbonate as well as any
secreted bicarbonate

Produces titratable acid

Secretes bicarbonate

Answer 22

Distal convoluted tubule and collecting duct system

Question 23

How is a new bicarb molecule reabsorbed for every NH4 excreted

Answer 23

NH4 is made when glutamine metabolizes into NH3 and HCO3, the bicrb gets reabsorbed and the NH3 combines with H+ to make NH4