Circulatory System- Blood Vessels Flashcards
What are the three different types of blood vessels and what are their functions?
artery- takes blood away from the heart
capillary- involved in the exchange of material at the tissues.
vein- takes blood to the heart
What pressure does the artery pump blood at?
-high pressure so they have thick and elastic walls
What is the lumen?
it is the hole in the artery and the walls are thick compared to it
What does the wall of the artery contain?
muscles to make strong and elastic fibres to stretch and spring back
What branches into the capillaries?
arteries
What is the size of the capillaries?
too small to see
Where do they carry blood to?
every cell in the body so they can exchange substances
Why are the walls of the capillaries permeable?
so substances can diffuse in and out
What do they supply and carry out?
food and oxygen
waste products
How thick are the walls of a capillary and why?
one cell thick which increases the rate of diffusion by decreasing distance over which it occurs
What do capillaries eventually join up to form?
veins
What is the blood pressure in the veins?
lower pressure so walls do not have to be as thick as arteries
What size is the lumen of the vein and what does it help do?
It’s bigger than the artery to help blood flow despite it being at a low pressure
Why do the veins have valves?
to keep the blood flowing in the right direction
What is the formula of rate of blood flow?
volume of blood/number of minutes
ml/min
