blood vessels Flashcards
capillaries characteristics
- narrow lumen and thin walls to allow red blood cells to be very close to to body cells for easy diffusion of oxygen out of cells
- walls made of squamous endothelium
- blood flows at low pressure
capillaries function
allow easy diffusion of substances between body and tissue cells
what do capillaries excrete
carbon dioxide
veins function
carry blood to the heart
vein characteristics
- thin walls with a small amount of muscle tissue
- large lumen
why is the lumen of veins irregular shaped?
they have thin muscle walls and are therefore floppy
varicose veins
enlarged and swollen veins due to the semilunar valves not functioning correctly and causes blood to pool under gravity
thrombosis
formation of a blood clot
pulmonary embolism
blockage in the pulmonary artery in the lungs
blood transfusion
transfer of blood from one person to another
best blood type to need a transfusion
AB
agglutination
when the antibodies and antigens of two different blood cells react causing the red blood cells to stick together. can be fatal as they block blood vessels
what must be examined for a blood donor
correct blood type
no pathogens in the blood
best blood type to give blood
O because it contains
purpose of a blood transfusion
restore blood and plasma volume
increase number of red blood cells
