Blood Vessels Flashcards
What are arteries?
Arteries are blood vessels that carry the blood away from the heart towards the organs.
name 2 properties of artery walls
strong and thick
True or false arteries contain thick layers of muscle
True
true or false the walls are thin compared to the hole down the middle in an artery
false the walls are thick compared to the small hole down the middle
What are capillaries?
capillaries are the things that arteries branch off into and they are involved in the exchange of materials at the tissues. They carry the blood really close to every cell in the body to exchange substances with them
How big are capillaries ?
Capillaries are very tiny - too small to see
Why do capillaries have permeable walls?
So that the substance exchange can happen and substances can diffuse in and out
How many cells thick are the walls of capillaries?
They are 1 cell thick
True or false capillaries are very narrow
true
Why is it good that capillaries are very narrow?
It gives them a larger surface area compared to the volume which increases the rate of diffusion
What are veins?
Veins are capillaries when they eventually join up, veins carry the blood to the heart.
Why do veins have a bigger lumen compared to the artery?
The bigger lumen helps the blood flow despite the lower pressure
True or false veins have valves? Why?
True it keeps the blood flowing in the correct direction
Whats the equation to work out the rate of blood flow?
Rate of blood flow=volume of blood/number of minutes
