Tissue fluid Flashcards
What components make up blood?
Plasma (actual fluid that all these compenents are suspended in)
platelets
red blood cells (erythrocytes)
white blood cells
What is the difference between tissue fluid and blood plasma?
Tissue fluid doesnt contain cells or plasma proteins (platelets)
Where is tissue fluid formed?
In capillary beds
What 5 components does tissue fluid contain?
water na+ & cl- ions urea glucose amino acids
How is tissue fluid formed?
Blood pumped by the heart passes through arteries then into narrower vessels known as arterioles and then finally into capillaries. This creates hydrostatic pressure at the arteriole end of the capillary.
This tends to force the fluid out of the blood.
The outward pressure is opposed by the hydrostatic pressure of the tissue fluid outside the capillaries (preventing outward movement of the liquid) and the lower water potential of the blood
Explain the return of tissue fluid to the circulatory system
The loss of tissue fluid rom capillaries reduces the hydrostatic pressure inside them
Blood reached the venous end of capillary network its hydrostatic pressure is lower than of the tissue fluid outside
Tissue fluid forced back into capillaries by the higher hydrostatic pressure outside
Plasma then loses water (have proteins), lower water potential in plasma than in tissue fluid
Water leaves the tissue by osmosis down a water potential gradient
Explain the return of tissue fluid to the circulatory system
The loss of tissue fluid from capillaries reduces the hydrostatic pressure inside them
Blood reached the venous end of capillary network its hydrostatic pressure is lower than of the tissue fluid outside
Tissue fluid forced back into capillaries by the higher hydrostatic pressure outside
Plasma then loses water (and still has proteins). It therefore has lower water potential than tissue fluid
Water leaves the tissue by osmosis down a water potential gradient
What is the lymphatic system?
Its a system of vessels that begin in the tissues and gradually merge into larger vessels that form a network throughout the body. These larger vessels drain their contents back into the blood stream via 2 ducts that join veins close to the heart
What moves the contents of the lymphatic system?
- hydrostatic pressure (of tissue fluid that has left the capillaries)
- contraction of body muscles (that squeeze the lymph vessels - valves in the lymph vessels ensure that the fluid inside them moves away from the tissues in the direction of the heart)
