The Circulatory System - Blood Vessels Flashcards
What are the 3 types of blood vessel?
Arteries, Capillaries and Veins
Where do arteries take blood?
Away from the heart (to organs)
What are capillaries involved in?
The exchange of materials at the tissues
Where do veins carry blood?
To the heart
The heart pumps the blood out at [ ] pressure
High
The artery walls are [ ] and [ ]
Strong and elastic
Artery walls are [ ] compared to the size of the hole down the middle (the [ ])
thick
lumen
Artery walls contain thick layers of [ ] to make them strong, and [ ] to allow them to stretch and spring back
Muscle
Elastic fibres
Arteries branch into [ ]
Capillaries
What size are capillaries?
Tiny
What do capillaries do?
Carry blood really close to every cell in the body to exchange substances with them
Capillaries have [ ] walls, so substances can [ ] in and out
Permeable
Diffuse
What do capillaries supply to cells? What do they take away?
Food and oxygen
Take away: Waste products (CO2)
How many cells thick are the walls of capillaries? Why?
One cell thick. Increase the rate of diffusion by decreasing the distance over which it occurs
Capillaries eventually join up to form…
Veins
The blood is at [ ] pressure in veins, therefore the walls are thicker/thinner than artery walls
low
Thinner
Do veins have smaller lumen than arteries? Why?
No, they have bigger lumen to help with blood flow despite the lower pressure`
What do veins have to help with blood flow (apart from bigger lumen)?
Valves, to help keep blood flowing in the right direction
