Brainscape's Knowledge GenomeTM

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


See full index

EMS > Lecture 31: Sodium and Water Homeostasis > Flashcards

Lecture 31: Sodium and Water Homeostasis Flashcards

1
Q

What percent of the brain is made up by water?

A

75%

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

What percent of the blood is made up by water?

A

83%

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

What percent of the heart is made up by water?

A

79%

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

What percent of the bones is made up by water?

A

22%

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

What percent of the muscles is made up by water?

A

75%

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

What percent of the Liver is made up by water?

A

85%

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

What percent of the kidneys is made up by water?

A

83%

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

Give three factors that affect body water distribution:

A

1) age

2) gender

3) fat content

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

What percentage of weight does total body water make up in males?

A

60%

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

What is the average total body water in a 70kg male?

A

42L

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

What fraction of total body water is intracellular fluid?

A

2/3

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

What fraction of total body water is extracellular fluid?

A

1/3

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

What fraction of extracellular fluid is plasma?

A

1/4

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

What fraction of extracellular fluid is extravascular fluid?

A

3/4

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

What is hydrostatic pressure?

A

the pressure exerted by the fluid against the membrane

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

What is osmosis?

A

The movement of water across a semipermeable membrane from low solute to high solute

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

What is osmotic pressure?

A

The ability of a solution to cause osmosis measured in mmHg

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

What is oncotic pressure?

A

The osmotic effect caused by large colloid particles/ protein such as albumin

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

Describe the distributive effects of water IV:

A

has a hydrostatic effect and is evenly distributed in intracellular, extracellular and intravascular compartments

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

Describe the distributive effects of saline IV:

A

has osmotic effect and is distributed in interstitial and vascular fluid

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

What percent of body weight in females is attributable to water?

A

55%

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

Describe the distributive effects of colloid IV:

A

has an oncotic effect and is distributed in intravascular fluid only

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

What are the two types of passive transport?

A

1) diffusion

2) fascilitated diffusion

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

What is facilitated diffusion?

A

Movement of specific molecules across cell membranes through protein channels down a concentration gradient

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

What is active transport?

A

movement against a concentration gradient requiring ATP and specialised transport proteins

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

What ion does water follow?

A

Na+

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

What other solute might water follow?

A

Glucose

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

Is sodium found more abundantly is extracellular or intracellular fluid?

A

extracellular fluid

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

Is potassium found more abundantly is extracellular or intracellular fluid?

A

Intracellular fluid

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

What is the name of a protein transporter that transports ions/ molecules in the same direction?

A

cotransporter

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

What is the name of a protein transporter that transports ions/ molecules in the opposite direction?

A

Exchanger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe the SGLT protein as an example as a cotransporter:

A

it moves both 2Na+ and one glucose molecule across the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe the sodium-calcium exchanger:

A

it moves 3Na+ in one direction for every Ca2+ pumped in the opposite direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Define osmolality:

A

The number of osmoles of solute particles per unit Kg (Weight of solvent)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the units of osmolality?

A

mmol/Kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Define osmolarity:

A

the number of osmoles of solute particles per unit litre (volume of solution)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the units of osmolarity?

A

mmol/L

38
Q

True or false: osmolality can be measured directly

A

True

39
Q

True or false: osmolarity can be measured directly

A

false (it has to be calculated)

40
Q

How is osmolarity calculated?

A

by adding all electrolytes and molecules that have an effect on water movement: 2x(Na+K) + urea + glucose (if abnormal)

41
Q

How is the osmolar gap calculated?

A

measured osmolality - calculated osmolarity

42
Q

What does an osmolar gap greater than 10 suggest?

A

the presence of other osmotically active solutes in the plasma that perhaps should not be there

43
Q

What is a hypertonic solution?

A

A solution with a higher solute concentration than the cell so water moves out of the cell and into the solution

44
Q

What is a hypotonic solution?

A

a solution with a lower solute concentration than the cell so water moves into the cell

45
Q

What is an isotonic solution?

A

a solution contains equal concentrations of solutes to a neighbouring solution resulting in equilibrium of movement

46
Q

Give three general ways in which water is lost:

A

1) insensible losses (500 ml)

2) GI loss (100 ml)

3) urinary loss (1.5-2.5L)

47
Q

Give two examples of insensible losses of water:

A

1) sweat

2) respiration

48
Q

True or false: where sodium goes, H2O will ALWAYS follow

A

True

49
Q

What is the rule about water and osmolality?

A

H2O WILL MOVE FROM AN AREA OF LOW OSMOLALITY TO AN AREA OF HIGH OSMOLALITY

50
Q

Describe how osmoreceptors help control water balance:

A

they detect changes in osmolality in extracellular fluid

51
Q

Which are more sensitive in the control of water balance, baroreceptors or osmoreceptors?

A

Osmoreceptors

52
Q

Describe how baroreceptors help control water balance:

A

they detect changes in intravascular volume

53
Q

Give three locations that baroreceptors are located in:

A

1) carotid sinus

2) main veins

3) right atrium

54
Q

When intracellular fluid is equal to extracellular fluid, what does osmolality equal?

A

285mmol/kg

55
Q

What control structures control the release of ADH?

A

hypothalamic osmoreceptors

56
Q

What is another name for anti-dieretic hormone?

A

arginine vasopressin (AVN)

57
Q

What structures produce ADH?

A

Supraoptic and paraventricular nuclei

58
Q

Where is ADH stored?

A

posterior pituitary gland

59
Q

Give two stimuli that alter stimulate ADH release:

A

1) shrinkage caused by loss of extracellular fluid

2) hypovolaemia (more potent stimulus)

60
Q

How does ADH increase water uptake?

A

it acts on the collecting duct to increase the secretion of aquaporin-2

61
Q

What effect does mercury have on aquaporin expression?

A

inhibition

62
Q

What 7 things is ADH secreted in response to?

A
  1. Hypovolaemia
  2. Hyperosmolality
  3. Stress
  4. Pain
  5. Trauma
  6. Drugs
  7. Nausea
63
Q

What effect does lithium have on aqauporin expression?

A

decreased

64
Q

What is the single most powerful non-osmotic stimulus of ADH?

A

Nausea

65
Q

What triggers thirst?

A

loss of extracellular fluid (but not intracellular fluid)

66
Q

Where does most (80%) of sodium reabsorption take place?

A

proximal tubule of the kidney

67
Q

Where does ‘fine tuning’ of sodium reabsorption take place?

A

distal convoluted tubules

68
Q

What hormone converts angiotensinogen to angiotensin I?

A

Renin

69
Q

What hormone converts angiotensin I to angiotensin II in the lungs?

A

ACE

70
Q

What stimulates renin release from kidneys?

A

systemic volume contraction

71
Q

Describe how aldosterone helps with Na+ uptake in the collecting duct of the kidney?

A

1) it stimulates the Na+/K+ ATPase transporter of collecting duct cells to generate intracellular electronegativity by pumping 3Na+ out for 2K+ in

2) the electrogenic Na+ channel on the apical boarder of the collecting duct cell allows Na+ entry from the lumen

3) K+ is secreted simultaneously to balance charge

72
Q

What two effects do natriuretic peptides cause?

A

1) vasodilation

2) increased loss of urinary sodium and water

73
Q

When are natriuretic peptides released?

A

When myocytes are mechanically stretched by increased plasma volume

74
Q

Give three examples of natruretic peptides:

A

1) atrial natriuretic peptide (ANP)

2) brain natriuretic peptide (BNP)

3) c-type natriuretic peptide (CNP)

75
Q

What is hyponatraemia?

A

where sodium levels are found below the normal range of 133-146mmol/L

76
Q

Give 8 symptoms of hyponatraemia: (SALT LOSS)

A

1) stupor (coma)

2) anorexia

3) lethargy

4) tendon reflexes decreased

5) limp muscles

6) orthostatic hypotension

7) seizures and headache

8) stomach cramping

77
Q

What diseases may present is hypovolaemia presents with hyponatraemia? (3)

A

1) heart failure

2) renal disorders

3) liver cirrhosis

78
Q

Give two causes of pseudohyponatraemia

A

1) hyperproteinaemia

2) hypertriglyceridemia

(both cause water imbalances)

79
Q

Give three causes of syndrome of inappropriate ADH (SIADH)?

A

1) malignant disease

2) neurological disorders

3) pulmonary disorders

80
Q

Give two treatments used for SIADH:

A

1) fluid restriction

2) demeclocycline (ADH antagonist)

81
Q

Give 3 presentations of SIADH:

A

1) hyponatraemia

2) high sodium in urine

3) normal renal function

82
Q

Give 6 fluids that Na+ can be lost from:

A

1) gastric juice

2) pancreatic juice

3) bile

4) ileal fluid

5) stool water

6) sweat

83
Q

What is hypernatraemia?

A

sodium levels found above the normal range of 133-146mmol/L

84
Q

Give 9 symptoms of hypernatraemia: FRIED SALT

A

1) flushed skin

2) restless, anxious

3) increased blood pressure

4) edema (peripheral and pitting)

5) decreased urine output

6) skin flushed

7) agitation

8) low grade fever

9) thirst

85
Q

How does Addison’s disease affect sodium levels?

A

the hypoaldosteronism causes sodium loss

86
Q

How does Conn’s syndrome affect sodium levels?

A

the primary hyperaldosteronism causes Na+ excess

87
Q

What is diabetes insipidus?

A

a disease where there is no effective ADH meaning no aquaporin uptake and subsequent water loss

88
Q

Give 2 general causes of diabetes insipidus:

A

1) pituitary or hypothalamus damage

2) issues with ADH receptors or aquaporins

89
Q

What test is used to check for diabetes insipidus?

A

water deprivation test

90
Q

What is the water deprivation test?

A

where a patient has restricted fluids for 12 hours while serum osmolarity and urine volume is regularly measured

EMS (54 decks)

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