Blood vessels and tissue fluid Flashcards
What is the general structure of a blood vessel (Inside to Outside)
LEEMT
Lumen
Endothelium - Reduce friction
Elastic layer - Maintain bp by stretch + recoil
Muscle - Can contract
Tough fibrous outer layer - Resist pressure change
Characteristics of artery
Muscle layer is thicker than veins
Elastic layer thicker than veins
Great overall wall thickeness
No valves
Characteristics of vein
Thin muscle layer
Thin Elastic layer
Small thickness of wall
Valves present at intervals
Characteristics of Arterioles
Carry blood under low pressure from arteries to capillaries
Thicker muscle layer than artery
Thinner elastic layer than artery
Characteristics of capillary
Exchange metabolic materials
Walls consist mostly of lining layer - Endothelium for short diffusion
Numerous and branched - High SA
Narrow diameter - No cell is far from capillary
Lumen narrow - RBC squeezed against wall, Reduce diffusion distance
Spaces between endothelial walls - WBC can escape
What does tissue fluid contain
containing glucose, amino acids, fatty acids, ions and oxygen
Received CO2 and other waste products
Formation and return of Tissue fluid
There is a high water potential and hydrostatic pressure at the arterial end of the capillary
Water, glucose and O2 move down pressure gradient to tissues
Water potential in capillary decreases, protein and cells remain
At venous end, water urea and CO2 move down water potential gradient into capillary via osmosis
Excess tissue fluid moves into lymph vessels and returns to the blood
Ultrafiltration
Pressure forces small molecules out through gaps in cells
What happens to remaining tissue fluid that cannot move back into vessels
Renters the lymphatic system via a lymphatic capillary
Vessels eventually transport contents into blood stream
How do the contents if the lymphatic system move around if not pumped by the heart?
Hydrostatic pressure of tissue fluid
Contraction of body muscles
