Tissue Fluid Flashcards
What is tissue fluid?
Fluid surrounding cells formed from blood plasma (without large proteins)
How is tissue fluid formed?
As blood flows through the capillaries, hydrostatic pressure is formed at the arterial end which forces tissue fluid (only small molecules) out of the blood plasma. This is due to outward pressure.
Describe ultrafiltration with tissue fluid.
Capillary hydrostatic pressure can only force small molecules out (not large like proteins- remain in blood)
What filters from blood to the tissue?
- Oxygen
- Glucose
- Amino acids
- Fatty acids
- Salts
What diffuses from the tissue into the blood?
- Carbon dioxide
- Waste products (e.g. urea)
Describe what occurs at the arterial end of the capillary with tissue fluid
Hydrostatic pressure is greater than water potential
Fluid is forced out capillary
Describe what occurs at the venule end of the capillary with tissue fluid
Water potential is greater than hydrostatic pressure
Water is reabsorbed by osmosis.
Why does hydrostatic pressure fall from the arteriole to venule end of the capillary?
This is due to a loss of fluid and therefore a loss of friction.
Why does high blood pressure lead to an accumulation of tissue fluid?
- High blood pressure = high hydrostatic pressure
- Increase in outward pressure
- More fluid leaves the capillary
- Formed at a greater rate than it is reabsorbed
Why is there a negative water potential at the venule end?
- Water has left the capillary
- Proteins in the capillary, too big to leave
- increase conc. and lower wp
