Brainscape's Knowledge GenomeTM

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


See full index

HUBS192 Lectures 1-38 > HUBS192 Lecture 33 - Renal Physiology: Body Water - Distribution and Regulation > Flashcards

HUBS192 Lecture 33 - Renal Physiology: Body Water - Distribution and Regulation Flashcards

1
Q

what drives and regulates body water homeostasis?

A
  • distribution of body water
  • osmolarity/tonicity of solutions
  • reabsorption of water in the nephron
  • changes in body osmolarity
  • effects of osmotic changes in the kidney
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how many percent of our total body weight (TBW) is water?

A

55-60%

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

how much of our total body weight (TBW) water is stored in the intracellular fluid (ICF)?

A

2/3

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

how much of our total body weight (TBW) water is stored in the extracellular fluid (ECF)?

A

1/3

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

how much of the water stored in the extracellular fluid (ECF) is stored as plasma?

A

1/5

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

how much of the water stored in the extracellular fluid (ECF) is stored as interstitial fluid?

A

4/5

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

what is osmolarity based on?

A

based on the number of osmotically active ions or solutes

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

what molecules determine osmolarity?

A
  • Na+
  • CI-
  • H2O
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how can osmolarity be estimated?

A

can be estimated by specific gravity (density of solutions)

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

what is iso-osmotic?

A

same osmolarity solutions

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

what is hypo-osmotic?

A

low osmolarity solutions

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

what is hyper-osmotic?

A

high osmolarity solutions

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

what is tonicity based on?

A

based on the effect of a solution on cells

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

what is an isotonic solution?

A

a solution that does not change water homeostasis between cells

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

what is the relationship between the composition of ECF, ICF and osmolarity?

A

no matter what the composition of ECF and ICF, osmolarity will always be in balance (have the same values for both ECF and ICF)

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

does total body water remain constant?

A

yes, total body water remains relatively constant

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

what are the 4 important places within the nephron where Na+ is reabsorbed?

A

1) proximal convoluted tubule (PCT)
2) the nephron loop
3) distal convoluted tubule (DCT)
4) collecting duct (CD)

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

where is 67% of the filtered load of Na+ reabsorbed in the nephron?

A

in the proximal convoluted tubule (PCT)

19
Q

where is 25% of the filtered load of Na+ reabsorbed in the nephron?

A

in the nephron loop

20
Q

where is 5% of the filtered load of Na+ reabsorbed in the nephron?

A

in the distal convoluted tubule

21
Q

where is 3% of the filtered load of Na+ reabsorbed in the nephron?

A

in the collecting duct

22
Q

how much percent of the filtered load of Na+ reabsorbed in the nephron is reabsorbed in the proximal convoluted tubule?

A

67%

23
Q

how much percent of the filtered load of Na+ reabsorbed in the nephron is reabsorbed in the nephron loop?

A

25%

24
Q

how much percent of the filtered load of Na+ reabsorbed in the nephron is reabsorbed in the distal convoluted tubule?

A

5%

25
Q

how much percent of the filtered load of Na+ reabsorbed in the nephron is reabsorbed in the collecting duct?

A

3%

26
Q

how much percent of the sodium excreted goes back into our system and why?

A

99% for blood pressure control - keep it constant

27
Q

what are the 3 important places within the nephron where water is reabsorbed?

A

1) proximal convoluted tubule (PCT)
2) distal late part of the distal convoluted tubule (tDLH)
3) collecting duct (CD)

28
Q

where is 67% of the filtered load of water reabsorbed in the nephron?

A

in the proximal convoluted tubule

29
Q

where is 25% of the filtered load of water reabsorbed in the nephron?

A

in the distal late part of the distal convoluted tubule

30
Q

where is 2-8% of the filtered load of water reabsorbed in the nephron?

A

in the collecting duct

31
Q

how much percent of the filtered load of water reabsorbed in the nephron is reabsorbed in the proximal convoluted tubule?

A

67%

32
Q

how much percent of the filtered load of water reabsorbed in the nephron is reabsorbed in the distal late part of the distal convoluted tubule?

A

25%

33
Q

how much percent of the filtered load of water reabsorbed in the nephron is reabsorbed in the collecting duct?

A

2-8%

34
Q

what is water reabsorption in the proximal convoluted tubule (67% of the filtered load) driven by?

A

driven by Na+ reabsorption

35
Q

what 2 things is water reabsorption facilitated by?

A

1) aquaporins (trans-cellular)

2) leaky tight junctions (paracellular)

36
Q

what uses the sodium gradient to reabsorb glucose?

A

transporters such as the sodium gluclose-cotransporter

37
Q

what is the permeability of the nephron loop?

A

permeability is low

38
Q

what are red blood cells dependant on?

A

dependant on an isotonic environment

39
Q

what is the range of osmolarity of ICF/ECF?

A

275-295 mosmol/L

40
Q

what is the process of regulation of total body water changes altering the plasma (ECF) osmolarity?

A
  • detected by osmoreceptors in the hypothalamus
  • stimulates the pituitary gland to secrete more/less ADH
  • ADH alters the permeability of renal collecting duct (CD)
41
Q

what are the 2 major stimuli for the release of ADH from the posterior pituitary gland?

A

1) increased ECF osmolarity

2) decreased blood volume

42
Q

what are the 2 actions from the release of the ADH hormone from the posterior pituitary gland?

A

1) inserts water channels (aquaporins) in the luminal membrane of the collecting duct
2) increases water reabsorption in the collecting duct

43
Q

what is obligatory water reabsorption?

A

not regulated and accounts for 92% of total water reabsorption

44
Q

what is facultative water reabsorption?

A

regulated by ADH through tight epithelia that is only transcellular and accounts for 2-8% of total water reabsorption

HUBS192 Lectures 1-38 (38 decks)

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