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1
Q

Hydrostatic P in glomerular capillaries

A

45 mm HG

2
Q

Hydrostatic P in Bowman’s space

A

10 mm HG

3
Q

Glomerular filtration rate

A

180 L day = 125 ml/min

4
Q

Filtered load

A

Amount of substance filtered across glomerular capsule

5
Q

Tubular fluid

A

Fluid in Bowman’s space and lumen of nephron

6
Q

Mechanisms of action for reabsorption

A

Transporters in membrane of tubular epithelial cells

7
Q

Most important function of kidneys and why

A

Reabsorb Na -> drives reabsorption of everything else

8
Q

Major cation in ECF

A

Na

9
Q

Increase in Na intake = increase in

A

Volume

10
Q

Examples of substances secreted from peritubular blood into tubular fluid via tubular epithelium

A

Organic acids
Organic bases
K+

11
Q

Cellular mechanism for glucose reabsorption

A

Carrier mediated along with Na in early PT

  • from tubular fluid into tubular cell via Na/glucose symporter SGLT
  • 2 Na (downhill) and 1 glucose (uphill)
  • Na/K pump on peritubular capillaries side keeps Na low in ICF
  • secondary active transport
12
Q

Glucose transported from tubular cell into peritubular blood by

A

Facilitated diffusion

GLUT 1 and 2 ( insulin dependent)

13
Q

Splay on glucose titration curve

A

Bending of reabsorption curve

Threshold - not all glucose reabsorbed

14
Q

Reasons for splay

A

Low affinity of Na glucose cotransporter

Heterogeneity of nephrons

15
Q

Glucosuria definition and observed in what conditions

A

High plasma glucose >200 mg/dL (DM)

Pregnancy (increased GFR which increases filtered load)

Congenital abnormalities of Na/glucose cotransporter

16
Q

___ freely filtered across glomerular capillaries

A

Urea

17
Q

__ transported in most segments of nephron

A

Urea

18
Q

Concentration of urea increases in tubular fluid as water is

A

Reabsorbed from tubule

19
Q

Urea secreted in

A

Thin descending limb

20
Q

Structures impermeable to urea

A

Thick ascending limb
Distal tubule
Cortical CD
Outer medullary CD

21
Q

More urea is secreted than was reabsorbed by

A

PCT

22
Q

Inner medullary collecting ducts have urea transporter 1 which is activated by

A

ADH

23
Q

Urea can by __ at high levels

A

Toxic

24
Q

__ and __ help create osmotic gradient at loop of Henle so water can be reabsorbed

A

Urea and salt

25
Q

Para-aminohippuric acid (PAH)

A

Used to measure renal plasma flow

26
Q

90% of PAH in blood bound to

A

Plasma proteins - not filterable

27
Q

Only ___ of PAH is filterable

A

10%

28
Q

PAH secretion

A

Transporters in peritubular membranes of PT cells

Inhibited by probenecid

29
Q

Excretion of PAH

A

Rises sharply as unbound plasma PAH levels rise

30
Q

Weak acids

A

PAH

Salicylic acid

31
Q

Weak bases

A

Quinine

Morphine

32
Q

Only ____ species of weak acids and bases can diffuse across tubular cells

A

Uncharged species

33
Q

Aspirin reabsorption

A

HA form = salicylic acid - reabsorbed

A- form = salicylate = not reabsorbed

34
Q

Positive Na balance

A

Excretion < intake

35
Q

Negative Na balance

A

Excretion > intake

36
Q

Positive Na balance; excess Na accumulates where

A

ECF = Increase BV and BP

Possible edema

37
Q

Negative Na balance; Na lost from

A

ECF

38
Q

Maintenance of ___ essential for normal function of excitable tissue

A

K

39
Q

Most (98%) of K is where

A

ICF

40
Q

___ major cation that exchanges for H

A

K

41
Q

Shifts of K from ICF to ECF

A
Insulin deficiency 
Beta 2 adrenergic antagonists
Alpha adrenergic agonists
Acidosis 
Hperosmolariry 
Cell lysis 
Exercise
42
Q

Shifts of K from ECF to ICF

A
Insulin 
Beta 2 adrenergic agonsits 
Alpha adrenergic antagonsits 
Alkalosis 
Hypoosmolarity
43
Q

___ increases activity of Na/K ATPase

A

Insulin

44
Q

High levels of insulin can result in

A

Hypokalemia

45
Q

Type 1 DM can result in

A

Hyperkalemia

46
Q

Insulin helps move ingested ___ into cells to prevent ____ after K rich meal

A

K

Hyperkalemia

47
Q

Acid base abnormalities are often associated with

A

K abnormalities

48
Q

K disturbances do not occur in ___ or ___

A

Respiratory acidosis or alkalosis

49
Q

K is not bound and freely filtered at

A

Glomerular capillaries

50
Q

___ reabsorbed 67% fo filtered load of K

A

PCT

51
Q

__ reabsorbs 20% of filtered load of K

A

Thick ascending limb

52
Q

Final adjustments to K secretion occurs in

A

Distal tubule and collecting duct

53
Q

K reabsorption occurs via

A

Alpha intercalated cells

54
Q

K secretion occurs by

A

Principe cells

55
Q

Loop diuretics and thiazide diuretics

A

Increase K excretion leading to hypokalemia

Produce profound kaliuresis and hypokalemia

56
Q

Thick AL impermeable to

A

Water

57
Q

Increase plasma osmolarity stimulates osmole receptors in

A

Anterior hypothalamus

58
Q

Vasa recta

A

Capillaries that serve medulla and papilla

59
Q

3 actions of ADH on renal tubule

A
  1. Increase water permeability of principal cells in Lae DT and CD
  2. Increase activity of Na/K/Cl cotransporter of TAL
  3. Increase urea permeability in inner medullary CD
60
Q

In nephron free water generated in

A

Diluting segment

61
Q

ADH low and effect on free water clearance

A

All free water excreted -> cannot be reabsorbed by collecting ducts

Free water clearance positive

62
Q

ADH high and effect of free water clearance

A

All free water reabsorbed by late distal tubule and CD

Free water clearance is negative

63
Q

Normal body pH

A

7.4

64
Q

Normal range of arterial pH

A

7.37-7.42

65
Q

Ph range compatible with life

A

6.8 to 8

66
Q

___ important as buffer in tubular fluid of kidney and intracellular buffer

A

Phosphate buffer

67
Q

All enzyme systems and body functions are altered by

A

H concentration

68
Q

Acidosis

A

Suppresses neuronal excitability —> coma

69
Q

Alkalosis

A

Excessive neuronal excitability —> convulsions

70
Q

3 mechanisms to maintain pH

A
Buffering (immediate)
Respiratory compensation (rapid)
Renal compensation (slower)
71
Q

Acidosis if blood»>

A

< 7.37

72
Q

Alkalosis if pH of blood…

A

> 7.42

73
Q

H secretion and HCO3 reabsorption occur in all parts of tubule except

A

TAL and TDL of loop of henle

74
Q

Most HCO3 reabsorption occurs in

A

Proximal tubule

75
Q

3 buffering systems

A

Bicarbonate
Phosphate
Proteins

76
Q

Powerful intracellular buffers

A

Proteins

77
Q

Most powerful regulators of pH

A

Kidneys

78
Q

Kidneys regulate ECF H concentration by 3 mechanisms

A

Secretion of H
Reabsorption of filtered HCO3
Production of new HCO3

79
Q

Secretion of H by secondary active transport occurs in

A

PT
TS of AL
Early DT

80
Q

H is combined with buffers in tubular fluid, and 2 main buffers

A

Phosphate

Ammonia

81
Q

Normal P co2

A

40

82
Q

Acidosis due to increase in PCO2

A

Respiratory acidosis

83
Q

Acidosis due to fall in HCO3

A

Metabolic acidosis

84
Q

2 forms of acid on body

A

Volatile

Fixed

85
Q

Example of volatile acid

A

CO2

86
Q

Examples of fixed acids

A

Sulfuric acid

Phosphoric acid

87
Q

Kidneys play 2 major roles in maintenance of normal acid base balance

A

Reabsortion of HCO3

Excretion of fixed H