renal part 3

Question 1

what is the normal pH range for the human body? what is the normal bicarbonate concentration?

Answer 1

normal pH range = 7.35-7.45

[HCO3-] = 24 m

Question 2

_______ acids can be exhaled or dissipated by the lungs; re: CO2

Answer 2

volatile

Question 3

________ acids from metabolism or the diet, and they must be regulated by the renal system

Answer 3

non-volatile

Question 4

________ bind to excess or free H+ to increase acid carried in urine without decreasing pH

Answer 4

buffers

Question 5

what buffers are used by the kidney?

Answer 5

HCO3- (bicarbonate)

HPO42- (phosphate)

NH3 (ammonium)

Question 6

_______ production within tubular cells eliminates H+ and produces an HCO3- that is reabsorbed

Answer 6

ammonium

Question 7

The kidney regulates acidity of the urine by regulating _______ reabsorption

Answer 7

HCO3- (bicarbonate)

Question 8

what are the 3 ways the kidney can regulate blood pH by using bicarbonate ions?

Answer 8

1. decrease body pH by not reabsorbing all HCO3-
2. no effect on body pH by reabsorbing all HCO3-
3. increase body pH by reabsorbing all and producing more HCO3- (typical)

Question 9

production and reabsorption of what molecule results in H+ secretion

Answer 9

bicarbonate

Question 10

where does bicarbonate reabsorption begin?

Answer 10

proximal tubule

Question 11

how is H+ secreted by the proximal tubule cells?

Answer 11

H+ is secreted via Na+ / H+ antiporter

can also have H+ ATPase pumps and H+/K+ ATPase pumps operating to secrete H+

Question 12

in the proximal tubule, HCO3- is transported/reabsorbed across _________ membrane

Answer 12

basolateral

Question 13

80% of filtered _________ is reabsorbed in proximal tubule

Answer 13

HCO3- (bicarbonate)

Question 14

how is H+ secreted by the cells of the late distal tubule, and the collecting duct?

Answer 14

H+ is secreted via an H+ ATPase pumps and an H+/K+ ATPase pump

Question 15

_________ cells of the distal tubule, and collecting duct, will excrete H+

Answer 15

intercalated

Question 16

what causes alkaline urine?

Answer 16

incomplete reabsorption of HCO3-

increase excretion of HCO3- by not neutralizing all that is in the tubular fluid

Question 17

Cells of the proximal tubule detect intracellular pH and can alter _________ activity accordingly

Answer 17

Carbonic anhydrase (CA)

Question 18

if the body is acidic, the kidney can use ______ as an additional buffer to increase excretion of H+

Answer 18

phosphate (HPO4- )

Question 19

After all HCO3- has been reabsorbed and HPO4- is depleted, the kidney will produce what?

Answer 19

ammonium (as a third buffer)

Question 20

NH4+ is produced in the proximal tubules by metabolism of _________

Answer 20

glutamine

Question 21

the NH4+ system is regulated by what?

Answer 21

systemic pH

Question 22

acidosis upregulates synthesis of enzymes for ________ metabolism

Answer 22

glutamine

Question 23

Much of the NH4+ leaving the proximal tubule is reabsorbed by what structure?

Answer 23

the ascending limb of the loop of Henle

Question 24

diffusion trapping can increase the concentration of ______ in the urine

Answer 24

NH4+ (ammonia)

Question 25

Net acid excretion (NEA) occurs after all filtered _________ is reabsorbed

Answer 25

HCO3-

Question 26

what causes Respiratory acidosis? how does the kidney respond to this?

Answer 26

low pH due to CO2 build-up renal compensatory response: produce new HCO3-

Question 27

what causes Respiratory alkalosis? how does the kidney respond to this?

Answer 27

high pH due to low PCO2 renal compensatory response: excrete HCO3-

Question 28

what causes respiratory alkalosis?

Answer 28

hyperventilation, anxiety, altitude, fever, drugs

Question 29

what causes Metabolic acidosis?

Answer 29

causes include diabetic ketosis, diarrhea, renal failure

Question 30

how does the respiratory system respond to metabolic acidosis? the kidneys?

Answer 30

respiratory compensatory response: hyperventilate renal compensatory response: produce new HCO3-

Question 31

what causes metabolic alkalosis?

Answer 31

causes include vomiting, antacids, hemorrhage

Question 32

how does the respiratory system respond to metabolic alkalosis? the kidneys?

Answer 32

respiratory compensatory response: hypoventilate renal compensatory response: excrete HCO3

Question 33

gastrointestinal absorption of _________ is balanced by renal excretion

Answer 33

calcium

Question 34

__________ increases excitability of neural and muscle tissue; tetany

Answer 34

hypocalcemia

Question 35

what are the effects of hypercalcemia?

Answer 35

cause cardiac arrhythmia and disorientation; can lead to death

Question 36

A decrease in ___________ will increase the amount of free Ca2+

Answer 36

plasma pH

Question 37

T/F: acidosis can lead to hypocalcemia

Answer 37

FALSE alkalosis can lead to hypocalcemia

Question 38

what 3 hormones regulate calcium levels?

Answer 38

1) parathyroid hormone (PTH) 2) calcitriol 3) calcitonin

Question 39

when is PTH secreted? what does it cause?

Answer 39

- released in response to hypocalcaemia | - increases bone resorption, increases renal Ca+ reabsorption

Question 40

PTH causes the production of what other hormone?

Answer 40

calcitriol

Question 41

how does calcitriol effect calcium uptake?

Answer 41

stimulates active transport mechanism for Ca2+ absorption in the intestine

Question 42

what is the molecular precursor for calcitriol?

Answer 42

vitamin D

Question 43

___________ will facilitates action of PTH and increases renal Ca2+ transport

Answer 43

calcitriol

Question 44

_________ (a hormone) is released in response to hypercalcaemia

Answer 44

calcitonin

Question 45

where is most calcium reabsorbed?

Answer 45

proximal tubule

Question 46

how is calcium absorbed by the thick ascending limb?

Answer 46

transcellular and paracellular transport

Question 47

what part of the nephron contains a basolateral calcium pump?

Answer 47

distal tubule

Question 48

what regulates the expression of Ca2+ transporters on the distal tubule?

Answer 48

regulated by PTH

Question 49

what structure of the nephron is NOT associated with Ca2+ reabsorption?

Answer 49

collecting duct

Question 50

how does calcitriol effect the GI tract?

Answer 50

causes INCREASED absorption of calcium (and phosphate)