Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physio Exam 3 > Jackson 7 > Flashcards

Jackson 7 Flashcards

1
Q

volatile acids - these by-products of

A

metabolism can be exhaled or dissipated by the lungs; re: CO2 is an acid because it produces H+ in the water of body fluids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

nonvolatile acids – arise from

A

metabolism or the diet; examples include phosporic, lactic, and sulfuric acids and ketones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

nonvolatile acids

must be neutralized with

A

HCO3-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

nonvolatile acids

are regulated by the

A

renal system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

nonvolatile acids

neutralization requires

A

continual replenishment of HCO3-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

In theory, the amount of acid in the urine should equal the

A

nonvolatile acid load

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The kidney accomplishes this by reabsorbing all of the filtered bicarbonte, and then producing

A

enough new bicarbonate to neutralize acids produced by the body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

However, lowest possible pH for urine is ~4.4 which represents very little free H+, and this pH of the urine is not sufficient to

A

excrete the nonvolatile acid load. Therefore, the kidney must excrete more acid than can be held in a solution with pH=4.4

Buffers provide the solution to this dilemma
buffers bind to excess or free H+ to increase acid carried in urine without decreasing pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Several molecules serves as physiological buffers. The kidney can produce HCO3- to act as a buffer, but it also adds

A

phosphate and ammonium to the filtrate to increase the amount of H+ excreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Kidney

phosphate used

A

first but supply is limited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Kidney

ammonium production within ———- eliminates H+ and produces an

A

tubular cells

HCO3- that is reabsorbed (more on this mechanism later)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Net acid excretion (NAE) should remove all nonvolatile acid

3 components or forms excreted are free

A

H+, HPO4-2, and NH4+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Urine contains both titratable acids and NH4+. H+ and HPO4- are the titratable acids and can be measured by titration with a base to a pH=7.4. NH4+ is not

A

titratable (pKa ~9)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Acid secretion and bicarbonate reabsorption along the nephron
The kidney regulates the acidity of the urine by regulating

A

HCO3- reabsorption. Under normal conditions, the kidney excretes acid equal to the nonvolatile load and replenishes the HCO3- lost due to neutralizing the nonvolatile acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

the collecting duct is not significantly involved with

A

Ca2+ reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

in distal tubule – transcellular reabsorption of

A

calcium

transport here can be regulated because expression of Ca2+ transporters is regulated by PTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The are three options for renal regulation of body pH that will produce urine with different pH

A
  1. decrease body pH by not reabsorbing all HCO3- ; produces an alkaline urine and acidifies body fluids
  2. no effect on body pH by reabsorbing all HCO3- ; urine has a neutral pH
  3. increase body pH by reabsorbing all and producing more HCO3- (typical); produces an acidic urine and alkalinizes body fluids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

A critical point to remember is that

A

HCO3- is not directly transported from tubular fluid into blood so HCO3- production and reabsorption results in H+ secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Bicarbonate reabsorption begins in the

A

proximal tubule, and 80% of filtered HCO3- is reabsorbed here.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

——- in the tubular epithelium produces H+ and HCO3-

A

CA activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

H+ is secreted via

A

Na+ / H+ antiporter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

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

A

secrete H+ (not illustrated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

HCO3- is transported/reabsorbed across

A

basolateral membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Some HCO3- is reabsorbed in the thick ascending limb of the loop of Henle in manner similar to the mechanism used in the

A

proximal tubule.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In the late distal tubule and the collecting duct

A

CA activity in the intercalated cells produces H+ and HCO3-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

H+ is secreted via an

A

H+ ATPase pumps and an H+/K+ ATPase pump (not illustrated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

the last of all filtered HCO3- is reabsorbed in the

A

late distal tubule and collecting duct.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

A less common type of intercalated cell reverses the position of the

A

H+ and HCO3- transporters to the basolateral and apical membranes, respectively. These cells reabsorbs H+ and secretes HCO3- ; activity of this cell type is normally very low.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

If the body is alkaline, the kidney must produce alkaline urine which requires

A

incomplete reabsorption of HCO3- (figure on right)

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Cells of the proximal tubule detect

A

intracellular pH and can alter CA activity accordingly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

If the body is acidic, use

A

phosphate (HPO4- ) as an additional buffer to increase excretion of H+

32
Q

After all HCO3- has been reabsorbed and

A

HPO4- is depleted, the kidney will produce ammonium as a third buffer to increase the amount of H+ that can be excreted.

33
Q

note that is important to keep NH4+ from entering body where it would be converted to

A

urea and produce H+ as a result

34
Q

NH4+ is produced in the ———– by metabolism of ———.

A

proximal tubules

glutamine

35
Q

The NH4+ that is produced is transported into the

A

tubular fluid and the HCO3- moves into blood.

36
Q

Production of NH4+ in the proximal tubule cells is regulated by

A

systemic pH.

37
Q

Acidosis upregulates synthesis of enzymes for

A

glutamine metabolism, but note that this takes time (as does all protein synthesis).

38
Q

More NH4+ can be added to the urine by

A

diffusion trapping.

39
Q

Much of the NH4+ leaving the proximal tubule is reabsorbed by the

A

ascending limb of the loop of Henle (note that the orientation of the tubule cell is reversed in the proximal tubule diagram below)

40
Q

NH4+ substitutes for

A

K+ in the Na+K+2Cl- symporter and enters the interstitial fluid in the medulla where it is in equilibrium with NH3

41
Q

Because it is a polar molecule, NH4+ is “trapped” in the interstitial fluid, but NH3

A

(being nonpolar) can diffuse into the lumen of nearby collecting ducts

42
Q

Because there is excess H+ in the fluid, NH3 in lumen is protonated to NH4+ , is once again

A

trapped, and gets eliminated with the urine

43
Q

• Respiratory system keeps PCO2 ——, kidneys regulate ==———

A

constant

bicarbonate

44
Q

• Net acid excretion occurs after all

A

filtered bicarbonate is reabsorbed

45
Q

• New bicarbonate can be produced in the proximal tubule by production of

A

NH4+ from glutamine

46
Q

• NH4+ produced in the proximal tubule facilitates

A

H+ excretion in the collecting duct as a consequence of diffusion trapping.

47
Q

Respiratory acidosis – low pH due to

A

CO2 build-up

48
Q

Respiratory acidosis

causes include -

A

impaired pulmonary function

49
Q

Respiratory acidosis

renal compensatory response—–>

A

produce new HCO3-

50
Q

Respiratory alkalosis – high pH due to low

A

PCO2

51
Q

Respiratory alkalosis;

causes include

A

hyperventilation, anxiety, altitude, fever, drugs

52
Q

Respiratory alkalosis;

renal compensatory response —–>

A

excrete HCO3-

53
Q

Metabolic acidosis - low pH due to low

A

HCO3-

54
Q

Metabolic acidosis

causes include

A

diabetic ketosis, diarrhea, renal failure

55
Q

Metabolic acidosis

respiratory compensatory response —->

A

hyperventilate

56
Q

Metabolic acidosis

renal compensatory response——>

A

produce new HCO3-

57
Q

Metabolic alkalosis – high pH due to excess

A

HCO3-

58
Q

Metabolic alkalosis

causes include

A

vomiting, antacids, hemorrhage

59
Q

Metabolic alkalosis

respiratory compensatory response –

A

hypoventilate (how does this work?)

60
Q

Metabolic alkalosis

renal compensatory response —–>

A

excrete HCO3-

61
Q

Calcium is found in the body in

A

intracellular fluid

extracellular fluid
bone

62
Q

only a little more than—— of ECF calcium is free or complexed with anions, and, therefore, can be filtered in the glomerulus

A

½

63
Q

Calcium (and phosphate) are important for many

A

cellular processes, and are regulated by renal and digestive systems so that gastrointestinal absorption is balanced by renal excretion.

64
Q

Why is it important to regulate calcium?

A

hypocalcemia increases excitability of neural and muscle tissue; tetany

hypercalcemia can cause cardiac arrhythmia and disorientation; can lead to death

65
Q

Note that a decrease in plasma pH will increase the amount of

A

free Ca2+ which can be filtered and excreted, so alkalosis can lead to hypocalcemia.

66
Q

Calcium reabsorption in the nephron

in proximal tubule –

A

mostly by paracellular transport/solvent drag

67
Q

Calcium reabsorption in the nephron

in thick ascending limb –

A

transcellular and paracellular transport (paracellular not solvent drag)

68
Q

• calcitonin

released in response to

A

hypercalcaemia

69
Q

calcitonin

increases

A

bone deposition

70
Q

Calcium is regulated by three hormones all of which are regulated by a

A

calcium sensing receptor (CaSR)

found in plasma membrane of cells in parathyroid gland, thyroid parafollicular cells, and cells of the proximal tubule.

71
Q

• parathyroid hormone (PTH)

released in response to

A

hypocalcaemia

72
Q

Calcium is regulated by three hormones

A

Parathyroid hormone
calcitonin
calcitriol

73
Q

Parathyroid hormone

increases

A

bone resorption, increases renal Ca+ reabsorption, and stimulates calcitriol production

74
Q

• calcitriol (1,25 dihydroxyvitamin D)

metabolism of

A

vitamin D to calcitriol is stimulated by hypocalcaemia and/or hypophosphatemia (and further stimulated by PTH, see above)

75
Q

Calcitriol

stimulates

A

active transport mechanism for Ca2+ absorption in the small intestine

76
Q

Calcitriol

facilitates action of

A

PTH and increases renal Ca2+ transport

Physio Exam 3 (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions