Circulatory System - Blood Vessels Flashcards
Name the three different types of blood vessel?
Arteries, capillaries and veins.
What do the arteries do?
They carry blood away from the heart.
What do the capillaries do?
They are involved in the exchange of materials at the tissues.
What do the veins do?
Carry the blood to the heart.
What is the blood like inside arteries?
The blood has a high pressure.
What are arteries walls like?
Strong, thick and elastic.
What is the lumen?
The hole down the middle.
What are arteries walls made up of?
Thick layers of muscle to make them strong and elastic fibres to allow them to stretch and spring back.
Are capillaries big or small?
Small.
What do arteries branch into?
Capillaries.
Where do capillaries carry the blood to?
They carry the blood close to every cell in the body to exchange substances with them.
What do capillaries have in order for substances to diffuse in and out?
Permeable walls.
What do they supply cells with and what do they air away?
They supply food and oxygen and take away waste such as carbon dioxide.
How thick are capillary walls?
Only one cell thick.
Why are capillary walls only one cell thick?
Because this increases the rate of diffusion by decreasing the distance over which it occurs.
What do veins do?
Veins take blood back to the heart.
What do capillaries eventually joins up to form?
They join up to form veins.
What pressure is the blood when it’s in the veins?
A low pressure.
What does this mean for the vein walls of the blood has a low pressure?
The walls in the veins don’t need to be as thick as the walls in the artery.
True or false the veins have a bigger lumen than the arteries?
True, despite the lower pressure veins have a bigger lumen than arteries.
What do veins have inside them?
Valves.
Why do the veins contain valves?
To keep the blood flowing in the right direction.
