Arteries, veins and capillaries Flashcards
What do arteries do?
They carry blood away from your heart (oxygenated)
Why are artery walls very thick?
They are under high pressure because of the pumping action of the heart and therefor need to be able to withstand this pressure without rupturing so have thick, muscular walls.
What do arteries branch into?
The branch into tiny networks of capillaries.
all living cells lie close to a capillary
Why are capillary walls very thin?
They are very thin which allows some plasma to leak out of tiny pores/slits to bathe the cells.
What is plasma known as when it leaks out the capillaries?
tissue fluid
What does the tissue fluid do?
It brings water with dissolved nutrients and oxygen to the surround cells.
During cellular respiration, body cells produce waste, what happens to this waste?
waste products and carbon dioxide pass into the tissue fluid which drains into the capillaries and blood
What do capillaries join up with?
they join up to form larger blood vessels called veins.
What do the veins do?
They carry blood back to the heart (deoxygenated)
Does blood moving back to the heart move fast/
No, because they are under less pressure which means they move slower
Are the walls of veins the same thickness of arteries?
No, they are thinner because they are under less pressure
Can blood flow anyway in the veins?
No, veins have one way valves that prevent the backflow of blood.
what is the result of damaged valves in the veins?
varicose veins.
what happens to the walls of the veins, when a valve is damaged?
the walls of the vein stretch, this results in pain and blood clot formation
