The Circulatory System - Blood Vessels Flashcards
What do arteries do:
Carry the blood away from the heart
Blood vessels are designed:
For their function
What are capillaries:
These are involved in the exchange of materials with the tissues
Veins:
These carry the blood to the heart
The artery walls are:
Strong, elastic and thick
Capillaries are:
Really small
What do capillaries do:
Carry the blood really close to every cell in the body to exchange substances with them
What are capillaries walls like:
They have permeable walls, so substances can diffuse in and out.
They are only one cell thick as this increases the rate of diffusion by decreasing the distance over which it occurs
What do capillaries supply:
Food and oxygen, and take away wastes like CO2
What do veins do:
Take blood back to the heart
What join up to form veins:
Capillaries
What are the walls like in veins:
The blood is at lower pressure in the veins so the walls don’t need to be as thick as artery walls
Lumen in veins:
They have a bigger lumen than arteries to help the blood flow despite the lower pressure
Valves in veins:
They have valves to help keep the blood flowing in the right direction
