Body water

Question 1

What are the functions of body water?

Answer 1

1. Solvent and transport medium
2. Absorption
3. Excretion
4. Medium for chemical reactions/Reagent
5. Ionization of atoms
6. Lubrication
7. Stabilising body temperature

Question 2

What properties of water make it suitable for its functions?

Answer 2

 great heat capacity
 good heat conduction
 high latent temperature of evaporation

Question 3

What factors effect the amount of body water?

Answer 3

Age
Sex
% Body fat

Question 4

Blood Plasma (ECF/ICF) and (Intravascular/ Extravascular)

Answer 4

ECF and intravascular

Question 5

What are two components of the ECF?

Answer 5

Interstitial fluid and blood plasma

Question 6

Does the body have water Reserves ?
Outline the intake and loss of water in the body?

Answer 6

NO
Water sources: direct intake + metabolism
Water loss: Lungs, Skin, urine, feaces

The body will be left with a net of 0 water, it has no place to be stored and a gradual loss will lead to dehydration.

Question 7

Define dehydration and state its causes, treatment and manifestation.

Answer 7

 Definition:
a state of excessive loss of body water
 Causes:
 Persistent vomiting, diarrhea, excessive sweating,
diuresis, insufficient water intake
 Treatment:
water per mouth or stomach tube,
saline infusion, etc.
 Manifestation:
Thirst, dry mouth and throat, difficulty with speech and swallowing
Loss of mass
Depression of the fontanelle in infants
↑ Pulse rate and haematocrit
↓ Blood pressure
Acidosis
Disorientation and collapse

Question 8

What is acidosis?

Answer 8

A condition in which the body fluids becomes acidic.

Question 9

Define osmosis?

Answer 9

spontaneous movement of water
through cell membrane into region of higher solute concentration

Question 10

Define osmolality?

Answer 10

The measure of solutes in a fluid.

Question 11

Name and Define the three types of Dehydration ?

Answer 11

Isosmotic: A decrease in water and electrolytes that leads to water leaving the blood which increases ECF volume.

Hyperosmotic: A loss of water that leads to the movement of fluids from cells into the blood decreasing ICF and ECF volume but increasing ICF and ECF osmolality.

Hyposmotic: A decrease in electrolytes that causes fluids to flow from the blood into the cell leading to an increase in ICF volume and a decrease in ICF osmolality and ECF volume and osmolality.

Question 12

What is trans-cellular fluid?

Answer 12

Portion of total body water contained within epithelial-lined spaces.

Question 13

Overhydration definition, causes, treatment and manifestation.

Answer 13

Definition: A state of excessive water content of the body

 Causes
 Excessive water intake, excessive infusion of saline, anuria, water retention

 Treatment: treat underlying condition, replace sodium

 Manifestation
 Oedema
 Haematocrit ↓
 Osmolality of blood plasma ↓
 Ultimately disorientation, convulsions, coma and death

Question 14

List the steps of water intoxication.

Answer 14

Increase in water uptake in cells, loss of function in brain cells, disorientation convulsions, collapse, coma, death.

Question 15

List and Explain the three types of overhydration.

Answer 15

Isotonic: An increase in water and electrolytes in the blood causes increased fluid in the blood which increases ECF volume.

Hypertonic: An increase in electrolytes in the blood causes the movement of fluid from cells into the blood, increasing ICF osmolality, ECF volume and osmolality and decreasing ICF volume.

Hyposmotic: An increase in water uptake causes fluids to move into the cells out of the blood, increasing ICF and ECF volume and decreasing ICF and ECF osmolality.