Body Fluid Distribution and Composition

Question 1

3 variation of body fluid composition.

Answer 1

1. Tissue type
2. Age
3. Gender

Question 2

How does tissue type, age and gender affect body fluid composition.

Answer 2

• ‘Tissue type: lean tissues have
  higher fluid content than fat
  tissues.
• *Gender: males have more lean
  tissue and therefore more body
  fluid.
• *Age: lean tissue is lost with age
  and body fluid is lost with it.

Question 3

What are two factors essential for homeostasis?

Answer 3

1. Body volume
2. Composition of body fluid (in components and its concentrations)

Question 4

What is insensible water loss and where does it occur?

Answer 4

Fluid lost by the body that cannot be measured and is usually by the skin or respiratory trat epithelia.

Question 5

Is insensible water loss dependent or independent of sweating?

Answer 5

> It is independent of sweating (only water not electrolytes).
DIFFUSION 300-400 l/Day
Does not require sweat glands to occur.

Question 6

What aspect of the skin minimizes excess diffusion?

Answer 6

Cholesterol filled cornified layer of the skin.

Question 7

When the cornified layer of the skin is denuded what occurs? (eg severe burn victims) What is done to combat this issue?

Answer 7

The rate of evaporation/ diffusion increases almost ten fold (3-5L per day)
>burn victims must be given large amounts of fluid, usually intravenously, to balance fluid loss.

Question 8

How much insensible water is lost by the skin and respiratory tract?

Answer 8

300-400ml/ day

Question 9

How is water lost insensibly via respiratory tract epithelia?

Answer 9

Inspired air is saturated with moisture before expelled
> leaves at vapor pressure 47 mm Hg but entered with lower vapor pressure proving increase in moisture.

Question 10

What is the rule of nine burns?

Answer 10

neck-4.5
head -4.5
right and left arm-9 each
right and left leg- 4.5 each
chest-9
stomach area (below chest)-9
groin-1
These are the TBSA in the Parland formula based on where burns are sustained.
Units in %

Question 11

What is Parklands formula?

Answer 11

4mL x Body Weight (kg) x TBSA (%) = Total crystalloid fluids in first 24 hours

Question 12

How should crystalline fluids be administered? (Time wise)

Answer 12

• First 1/2 of fluids given in the first 8 hours
• Second 1/2 of fluids given over the next 16 hours

Question 13

What is the average body fluid weight in humans? What percent of the body fluid is water?

Answer 13

42L
60 % of body fluid weight is water

Question 14

What % of body water is ICF, ECF (interstitial fluid and plasma)

Answer 14

ICF- 40%
ECF-20%
interstitial fluid- 3/4 of ECF
plasm- 1/4 of ECF

Question 15

What is interstitial fluid?

Answer 15

This is the fluid in the body that exists in the space between the cells and the capillaries. (no plasma proteins or cells because the semi-permeable membrane of cells keep contents in- only osmosis- and capillary membrane keeps plasma proteins and red blood cells etc in capillaries).

Question 16

How does blood contain both ICF and ECF? Why is blood considered as its own fluid compartment?

Answer 16

Blood contains both extracellular fluid (the fluid in plasma) and intracellular fluid (the fluid in the red blood cells). However, blood is considered to be a separate fluid compartment because it is contained in a chamber of its own, the circulatory system.

Question 17

what is the fluid inside red blood cells called?

Answer 17

Hematocrit

Question 18

Interstitial fluidis an……of plasma

Answer 18

Interstitial fluidis anultrafiltrateof plasma: It has nearly the same composition as plasma, excluding plasma proteins and blood cells.
This is because of presence of highly permeable capillary membranes.