Brainscape's Knowledge GenomeTM

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


See full index

Physiology I Exam 2 > Lecture 7: Regulation of Sodium Balance > Flashcards

Lecture 7: Regulation of Sodium Balance Flashcards

1
Q

What solute determines ECF volume (which in turn determines plasma volume, blood volume, and blood pressure)?

A

Sodium

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

Na+ excretion in comparison to Na+ intake

A

Must be equal

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

Positive Na balance

A

Na excretion less than intake (leads to ECF volume expansion and high blood pressure)

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

Negative Na balance

A

Na excretion greater than intake (Blood pressure decreases)

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

Na content definition

A

Absolute amount

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

Na concentration definition

A

Determined by amount of Na+ volume water

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

Na is usually expressed as

A

Concentration

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

Na is _________ and _______ throughout the nephron

A

Freely filtered and reabsorbed

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

Most Na+ reabsorption occurs in the

A

Proximal convoluted tubule

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

Water reabsorption is linked to what?

A

Na+ reabsorption in the PCT

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

How much filtered Na+ does the thick ascending limb reabsorb?

A

25%

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

What is special about the thick ascending limb?

A

Impermeable to water

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

Distal tubule and collecting ducts reabsorb how much filtered Na+?

A

8%

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

Where does fine tuning of sodium reabsorption and aldosterone occur?

A

Distal tubule and collecting ducts

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

What is the mechanism for Na+ reabsorption in the Early PCT?

A

Sodium (Na) absorbed mostly with bicarb, glucose, AA

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

What is the mechanism for Na+ reabsorption in the Late PCT?

A

Na absorbed mostly with Cl

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

How much filtered Na does the PCT reabsorb?

A

67%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How much filtered water does the PCT reabsorb?

A

67%

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

What is the term for when Na+ and water are reabsorbed together?

A

Isosmotic reabsorption

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

Where is the site for glomerulotubular balance?

A

PCT

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

Glomerulotubular balance definition

A

Major regulatory mechanism in PCT to ensure that a constant fraction of filtered load is reabsorbed, regardless of GFR

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

Where is the highest priority reabsorptive work done?

A

Early PCT

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

What solutes are considered highest priority reabsorptive work?

A

Na+, glucose, amino acids, HCO3-

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

Transport from the luminal membrane method is mostly

A

Secondary transport

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

Name the counter transport method for the luminal membrane into the cell in the early PCT

A

Angiotensin 2

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

How much filtered glucose and AA are reabsorbed by the mid-PCT?

A

100% filtered glucose and AA

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

What % HCO3 reabsorbed by mid-PCT?

A

85%

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

Fanconi Syndrome is

A

A kidney tubule disorder

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

Cystinosis

A

Accumulation of AA cystine within cells –> Crystals

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

Cystinuria

A

Persistent kidney stones caused by increased cystine in urine

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

How is Fanconi Sydrome diagnosed?

A

Increased level of acid in blood
And glucose, AA, phosphate in the urine

32
Q

What is fluid entering the late PCT high in?

A

Cl-

33
Q

NaCl is absorbed where?

A

Late PCT

34
Q

What drives NaCl absorption in the late PCT?

A

High tubular fluid (TF) Cl concentration

35
Q

Name the two routes for NaCl absorption in late PCT

A

Paracellular and cellular

36
Q

Cellular route methods (2)

A

Na+/H+ exchanger (luminal)
Cl-/formate-change (luminal)

37
Q

Paracellular route definition

A

Tight junctions loose and permeable to small solutes

38
Q

Paracellular route explanation

A

Cl- diffuses, followed by Na+

39
Q

What is coupled in proportion in the PCT?

A

Solute and water reabsorption

40
Q

What is the primary event of isosmotic reabsorption of Na and water in PCT?

A

Solute reabsorption (water follows passively)

41
Q

Reabsorption of isosmotic fluid is dependent on what?

A

High oncotic pressure in peritubular capillaries

42
Q

What transport system removes Na+ from the cell in the PCT?

A

Na+/K+ ATPase

43
Q

Glomerulotubular mechanism

A

If filtration fraction increases, then oncotic pressure in peritubular capillaries increases, thus reabsorption increases

44
Q

Increased GFR means higher volume of what?

A

Ultrafiltrate

45
Q

Glomerulotubular balance results in what?

A

Most concentrated blood in efferent arteriole

46
Q

What will influence tubular reabsorption and over-ride glomerulotubular balance?

A

Changes in ECF volume

47
Q

Volume expansion causes a decrease in what in PCT?

A

Fractional reabsorption

48
Q

If ECF volume is increased, then what pressure decreases?

A

Peritubular capillary oncotic pressure

49
Q

A decrease in peritubular capillary oncotic pressure causes what to increase?

A

Capillary fluid pressure

50
Q

Volume contraction causes an increase in what in PCT?

A

Fraction reabsorption

51
Q

What is also activated to low blood volume and BP?

A

RAAS

52
Q

During volume contraction, what increases due to ECF volume decreasing?

A

Capillary oncotic pressure

53
Q

What decreases due to capillary oncotic pressure increasing?

A

Capillary fluid pressure

54
Q

What does the decrease in capillary fluid pressure lead to?

A

Increase in fractional reabsorption by peritubular capillaries

55
Q

Thin descending limb is permeable to what

A

Reabsorption of water and secretion of small solutes (NaCl and urea)

56
Q

What happens in the thin descending limb?

A

What moves out and small solutes move in, the TF becomes hyper-osmotic

57
Q

Thin ascending limb is permeable to

A

Reabsorption of NaCl

58
Q

What thin ascending limb impermeable to?

A

Reabsorption of water

59
Q

What happens in the thin ascending limb?

A

Solutes move out, so the TF becomes hypo-osmotic (Because water stays)

60
Q

How much filtered Na is reabsorbed by the thick ascending limb?

A

~25%

61
Q

What co-transporters pull Na from lumen to cell of thick ascending limb?

A

Na+/2Cl/K+ co-transporters

62
Q

Where is the site of action for many loop diuretics (furosemide)?

A

Thick ascending limb

63
Q

Thick ascending is special because it is

A

Impermeable to water, water cannot follow NaCl here

64
Q

How does furosemide act?

A

Acts on anion in Na+/2Cl/K+ co-transporter, binds to Cl- portion and blocks its action

65
Q

What parts make up the terminal nephron?

A

Collecting ducts and distal tubule

66
Q

How much filtered Na+ is reabsorbed in the distal tubule and collecting ducts?

A

8%

67
Q

How much filtered Na+ is reabsorbed through the early DT?

A

~5%

68
Q

What co-transporter does the early DT use?

A

Na+/Cl- co-transporter

69
Q

What are the two major cell types in the late DT and collecting duct?

A

Principle cells
Alpha intercalated cells

70
Q

What are principal cells?

A

Responsible for Na reabsorption if that occurs, K secretion, water absorption

71
Q

What are alpha intercalated cells responsible for?

A

K absorption and H secretion

72
Q

How much Na is reabsorbed by the Late DT and collecting Duct?

A

3% (fine-tuning of final Na+ excretion)

73
Q

Principal cells use what transport method for Na?

A

Na+ channels and diffusion (NOT co-transport)

74
Q

Where is Na+ absorption hormonally regulated?

A

Principle cells of late DT and CT

75
Q

How does aldosterone increase Na+ reabsorption?

A

Via increase in number of Na channels and activity of Na+/+ ATPase

76
Q

What is Na+ reabsorption inhibited by?

A

K+ sparing diuretics

77
Q

Spironolactone

A

Inhibits aldosterone effects –> Prevents aldosterone from enteringcell

Physiology I Exam 2 (12 decks)

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