Brainscape's Knowledge GenomeTM

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


See full index

HUBS 192 > Lecture 33: Body water - distribution and regulation > Flashcards

Lecture 33: Body water - distribution and regulation Flashcards

1
Q

What % of our body weight is water?

A

55-60% of our body weight

  • Males 60%
  • Females 55%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What proportion of our TBW is ECF?

A

1/3

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

What proportion of our TBW is ICF?

A

2/3

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

What proportion of ECF is plasma?

A

1/5

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

What proportion of ECF is interstitial fluid?

A

4/5

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

What is osmolarity based on?

A

The number of osmotically active ions or solutes

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

What can osmolarity be estimated by?

A

Specific gravity

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

What does iso-osmotic mean?

A

Same osmolarity

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

What does hypo-osmotic mean?

A

Lower osmolarity

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

What does hyper-osmotic mean?

A

Higher osmolarity

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

What is tonicity based on?

A

The effect of a solution on cells

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

What does an isotonic solution not do?

A

Change water homeostasis between cells

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

What is the sodium concentration in the ECF?

A

145 mmol/L

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

What is the potassium concentration in the ECF?

A

4-5 mmol/L

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

What is the sodium concentration in the ICF?

A

15 mmol/L

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

What is the potassium concentration in the ICF?

A

150 mmol/L

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

What is particular about the osmolarity between the the ICF/ECF

A

They are the same/similar

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

Total body water remains relatively what?

A

Constant

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

Intake and loss of water must be in what?

A

Balance

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

Urine output is adjusted to do what?

A

Maintain balance

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

What is water output most effected by?

A

Kidneys producing urine

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

What are the 4 important places within the nephron where sodium is reabsorbed?

A
  • Proximal convoluted tubule(PCT)
  • Thick ascending loop (TAL)
  • Distal convoluted tubule (DCT)
  • Collecting duct (CD)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What % of sodium is reabsorbed in the PCT?

A

67%

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

What % of sodium is reabsorbed in the TAL?

A

25%

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

What % of sodium is reabsorbed in the DCT?

A

5%

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

What % of sodium is reabsorbed in the CD?

A

3%

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

What are the 3 important places within the nephron water is reabsorbed?

A
  • PCT
  • Thin descending loop (tDL)
  • CD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What % of water is reabsorbed in the PCT?

A

67%

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

What % of water is reabsorbed in the tDL?

A

25%

30
Q

What % of water is reabsorbed in the CD?

A

2-8%

31
Q

What % of water is excreted as urinary secretion?

A

0.5 - 8% of the filtered load

32
Q

What is needed to make you own Powerade?

4

A
  • Water
  • Sugar
  • Sodium
  • Flavour/vitamins
33
Q

What is water reabsorption in the proximal tubule driven by?

A

Sodium reabsorption

34
Q

What do transporters such as the sodium glucose-cotransporter use to reabsorb glucose?

A

The sodium gradient

35
Q

The thick ascending loop reabsorbs sodium into the interstitial generating what?

A

A high osmotic medullary gradient (HOMG)

36
Q

`The thin descending loop is leaky epithelium facilitating what?

A

Water reabsorption

37
Q

Water reabsorption in the thin descending loop can occur how?
(2)

A
  • Via aquaporins (transcellular)

- Via the paracellular pathway

38
Q

Obligatory water reabsorption is not what?

A

Regulated

39
Q

Obligatory water reabsorption account for what % of total water reabsorption

A

92% of total water reabsorption

40
Q

Facultative water reabsorption in the CD has what type of epithelium?

A

Tight epithelia

41
Q

What 2 types of water reabsorption can occur in the CD?

A
  • Obligatory water reabsorption

- Facultative water reabsorption

42
Q

Facultative water reabsorption uses only what type of pathway?

A

Transcellular

43
Q

What is regulated reabsorption in the CD regulated by?

A

ADH

44
Q

Facultative water reabsorption account for what % of total water reabsorption?

A

2-8% of total water reabsorption

45
Q

Changing water contents does what?

A

Changes osmolarity

46
Q

What does fluid shift between to equalise osmolarity?

A

ECF - ICF

47
Q

What does changing water contents do to a cell?

A

Changes the size of the cell

48
Q

What does a change in the size of cell do?

2

A
  • Cell structure altered

- Cell functions become impaired

49
Q

What does a hypertonic solution do to red blood cells?

A

Causes water to move out of the cell and it to shrivel

50
Q

What does an isotonic solution do to red blood cells?

A

Causes water to move in/out at a constant rate

51
Q

What does a hypotonic solution do to red blood cells?

A

Causes water to move into the cell and it to swell

52
Q

What are red blood cells dependent on?

A

An isotonic environment

53
Q

What do hypertonic/hypotonic environments to to red blood cells?

A

Alter their function

54
Q

What does TBW changes alter?

A

Plasma (ECF) osmolarity

55
Q

What are changes to osmolarity of ECF detected by?

A

Osmoreceptors in the hypothalamus (Brain)

56
Q

When changes to osmolarity of ECF are detected what happens?

A

It stimulates the pituitary gland to secrete more/less ADH

57
Q

What does ADH alter the permeability of?

A

The renal collecting duct

58
Q

When the permeability of the renal collecting duct is altered by ADH what happens?

A

Water is retained or excreted to balance initial change in TBW

59
Q

What happens to water re-absorption and urine production without ADH?

A

Diuresis - Large volume of dilute urine

60
Q

What happens to water re-absorption and urine production with ADH?

A

Anti-diuresis - small volume of concentrated urine

61
Q

ADH in the blood stream finds what?

A

Its receptor on the basolateral side of CD cells

62
Q

What does ADH via intracellular signalling cascades increase the number of?

A

Aquaporins in the apical membrane of CD

63
Q

What does an increase in aquaporins in the apical membrane of CD do?

A

Increases water permeability of the apical membrane

64
Q

What can macula dense cells sense?

A

Changes in sodium reaching the distal tubule and therefore perfusion of the nephron

65
Q

If sodium levels reaching the distal tubule is too low what happens?

A

It leads to a release of renin from juxtaglomerular cells

66
Q

What is a decrease in ECF volume by fluid loss detected by?

A

Baroreceptors/kidney

67
Q

What does a decrease in ECF volume detected by the kidneys causes the kidneys to do?
(2)

A
  • Renin release leading to angiotensin II activation

- Increased aldosterone

68
Q

What does renin release leading to angiotensin II activation and increased aldosterone lead to?
(2)

A
  • Decrease sodium loss in urine

- Decreased water loss in urine

69
Q

What is an increase in ECF volume or fluid gain detected by?

A

Cardiac cells

70
Q

What is an increase in ECF volume detected by cardiac cells to do?

A

Cause the release of natriuretic peptides

71
Q

What do natriuretic peptides have an effect on?

3

A
  • Hypothalamus
  • Kidneys
  • Blood vessels
72
Q

What does the hypothalamus, kidneys and blood vessels cause when activated by natriuretic peptides?
(2)

A
  • Increase in sodium loss in urine

- Increased water loss in urine

HUBS 192 (38 decks)

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