Topic 5 - Blood Vessels Flashcards
what are the three types of blood vessel?
arteries, capillaries and veins
where do arteries carry blood?
away from the heart
where do capillaries carry blood?
to the exchange of materials at the tissues
where do veins carry blood?
to the heart
why are artery walls strong and elastic?
the heart pumps the blood out at high-pressure
what makes artery walls elastic?
elastic fibres allow arteries to expand
what makes artery walls strong?
they are thick compared to the lumen and contain thick layers of muscle
what is the largest artery in the body?
the aorta
what do arteries branch into?
capillaries
are capillaries large?
no, they are very small
where do capillaries carry blood?
very close to every cell in the body to exchange substances with them
how are capillaries adapted for diffusion?
- they have permeable walls
- their walls are usually only one cell thick
what do capillaries supply and take away?
they supply food and oxygen
they take away waste
what do capillaries join up to form?
veins
why are the walls of veins not as thick as the artery walls?
the blood is at a lower pressure
