Tri A - Body Fluids

Question 1

How much water is in the body?

Answer 1

~60%

Question 2

How does body water % differ for high/low body fat?

Answer 2

High body fat = ~40%
Low body fat = ~80%

Question 3

What regulates body water content?

Answer 3

Hormones,
Circulatory Mechanisms,
Renal Mechanisms (Kidneys)

Question 4

What are the 2 components of body water?

Answer 4

1. Intracellular Fluid - water inside the cell
2. Extracellular Fluid - water outside the cell

Question 5

What are the 2 categories of Extracellular fluid?

Answer 5

1. Fluid surrounding the cell - interstitial fluid
2. Fluid in circulatory system - plasma

Question 6

Where is water lost from and how much?

Answer 6

Kidneys - 0.5-1.5 L/day
Lungs - 0.3-0.4 L/day
Skin - 0.2-1 L/day
Faeces - 0.1-0.2 L/day

Question 7

What is the difference in composition in Plasma and Interstitial Fluid and why?

Answer 7

Very small particles are free to move across capillaries but bigger particles cannot, so Ionic composition is similar but there are many more proteins in plasma

Question 8

Where is Cerebrospinal Fluid found?

Answer 8

Spaces within the brain, cerebral ventricles,

Question 9

Describe the composition of Cerebrospinal Fluid

Answer 9

No cells present,
Protein concentration is lower than plasma,
Different ionic content than plasma

Question 10

What is the function of Cerebrospinal Fluid?

Answer 10

Supports and protects the brain and spinal cord, helps supply nutrients

Question 11

Explain the Blood-Brain Barrier

Answer 11

Brain capillaries are less permeable, so they prevent certain substances from passing from the CSF to blood

Question 12

What is the purpose of the Blood-Brain Barrier?

Answer 12

It maintains a constant brain environment