Endocrine regulation of Body Water Flashcards

Wk 10

1
Q

What are the 5 important aspects of body fluids?

A

1- electrolyte balance and osmoregulation

2- transportation

3- metabolic reactions

4-pH Balance

5- Temperature regulation

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

What are body fluids secrted into?

A

joints, cerebral ventricle and intestinal lumen

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

How is body fluid distributed between interstitial and intracellular space?

A

Via osmosis

Water crosses cell membrane rapidly to equalise particle concentration

Not permeable to electrolytes

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

What are the six major electroylates?

A

Sodium, potassium, Chloride, calcium, magnesium, bicarbonate

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

What is the role of Chloride?

A

Helps maintain osmotic pressure and water balance by working with Na.

Forms HCL as gastric juice = digestion and killing bacteria

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

What is the most abundant anion in the ECF?

A

Chloride

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

what is the most abundant cation in the ECF?

A

Sodium

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

What is the role of sodium?

A

Maintain fluid balance

Nerve signal transmission and muscle function

Regulation of blood pressure and volume

Aids transport others

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

What is the distribution and role of Potassium?

A

Distribution= mostly in ICF

Maintaining fluid balance, transmitting nerve signals and regulating heart and muscle contractions

Creates K gradients needed for electrical activity of cells

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

What are the important roles of calcium?

A

Bone structure

Crucial neurotransmitter release in nerve cells

Muscle contraction and blood clotting

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

What is the distribution and role of Magnesium?

A

Used in over 3000 enzyme reactions

Essential for DNA and protein synthesis

Cellular energy production processes

Supports normal nerve and muscle function

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

What is the role of bicarbonate?

A

Buffer for pH of blood and others

Counteracts effects of acid produced in metabolic processes

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

What constituents organic substances?

A

Glucose, amino acids, fatty acids, lipids, hormones and enzymes

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

what constitutes inorganic substances?

A

Na, K, Ca, Mg2+, HCO3-, PO3, SO4

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

Are there more negatively or positively charged ions in plasma?

A

Positively

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

What do plasma proteins hold?

A

cations in plasma

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

What is the physiological effect of isotonic saline?

A

does not cause fluid to move into/out of cells = stabilises BP and V

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

What are the physiological effects of hypertonic saline?

A
  • high osmolality = draws water out of cells

-reduces cell swelling

-increases extracellular fluid volume

-helps restore blood pressure and circulation

19
Q

what are the physiological effects of hypotonic saline?

A
  • lower osmolarity = water in ECF –> ICF = expanded cells

lead to cellular edema or cerebral edema

20
Q

What two compartments does capillary fluid exchange occur between?

A

Movement between vascular compartments and interstitial compartments

21
Q

What is hydrostatic pressure

A

pushing force exerted by a fluid

22
Q

What is interstitial fluid pressure?

A

force of fluid in interstitial space pushing against the outside of the capillary wall

23
Q

What is colloidal osmotic pressure and why is it created?

A

pulling force created by plasma proteins (because can’t cross membrane)

24
Q

What are the three ways that hormones regulate balance of body water, sodium and potassium?

A

Thirst: detected and stimulated by hypothalamus

Volume and concertation of water in urine

Peripheral resistance- affects BP

25
Q

What are the hormones involve din fluid balance

A

ADH

Angiotensin II

Aldosterone

Atrial natriuretic peptide

26
Q

What is the thirst mechanism?

A

Primary regulator of water intake

Conscious sensation that need to drink fluids high in water

27
Q

What is the stimuli for the thirst mechanisim?

A

cellular dehydration

decreased blood volume

Angiotensin II (back up system for thirst)

28
Q

What inhibits the thirst mechanism?

A

Moistening of mucosa in mouth and throat

Activation of stomach and intestinal stretch receptors

29
Q

What is hypodipsia?

A

Decreased ability to sense thirst

Associated with Lesions in hypothalamus from head trauma and subarachnoid haemorrhage.

30
Q

What is polydipsia?

A

Excessive thirst normal if with conditions of water deficit.

31
Q

What are the three principle electrolytes in the ECF?

A

Sodium
Chloride
Bicarbonate

32
Q

What organ efficiently regulates Na levels?

A

kidney

33
Q

What is Hyponatremia and what is caused by?

A

Decreased Na

Most common electrolyte disorder

Caused by:

Loss of body sodium – Increased ECF volume – Diarrhoea – Vomiting – Diuretics – Addison’s disease – Dilutional hyponatremia – Excess ADH

34
Q

What is hypernatermia and what is it caused by?

A

Increased Na levels

Caused by: Decrease in ADH (diabetes insipidus) – Decreased water intake – Hyper secretion of aldosterone

35
Q

How much does K have to increased by to cause serious cardiac problems?

A

as little as 0.3-0.4mEq/L

36
Q

What are the two mechanisms that regulate K levels?

A

Renal mechanism: conserves or eliminates it

Aldosterone: regulates elimination of K by the kidney

37
Q

What is the effect of hyperkalemia?

A

Muscle dysfunction due to hypopolarisation.

Easier to initiate action potentials = cardiac arrythmias = stop contacting in severe cases

37
Q

What disorder electrolyte can result from hypopolarisation?

A

Hyperkalemia

38
Q

Describe the mechanism in which hypokalaemia alters cardiac function.

A

Decreased Extracellular K –> hypokalaemia –> hyperpolarisation of cardiac myocytes –> cardiac arrhythmias –> stop contracting

39
Q

What is a edema?

A

Accumulation of fluid within interstitial spaces (extra fluid in body tissues)

40
Q

What are some of the specific causes of edemas?

A

Increased hydrostatic pressure

Lowered plasma osmotic pressure

Increased capillary membrane permeability

Lymphatic channel obstruction

Increased tissue osmotic pressure

41
Q

What are the two types of edemas?

A

Pitting and non-pitting

42
Q

What is the cause of pitting edema vs non-pitting edema?

A

pitting = Excess water in interstitial spaces

non pitting = Mucopolysaccharides which hold water