Topic 2 Circulatory system - Blood Vessels + Flashcards
What do arteries do
Carry oxygenated blood away from the heart (except pulmonary artery which is deoxygenated blood)
What do capillaries do
Involved in the exchange of materials at the tissues
What do veins do
Carry deoxygenated blood to the heart (except the pulmonary vein which is oxygenated)
What could cause a heart valve to not function properly
Infection
Old age
Previous heart attack
Structure of an artery
Thick artery walls that are strong elastic as blood is under high pressure
Smaller lumen
Contains thick layers of muscle to make them strong and elastic fibres to allow them to stretch in spring back
What do arteries branch into
Capillaries
Structure of capillaries
Small only allow one red blood cell through at a time
Carry blood really close to every cell in the body to exchange substances with them
Have permeable walls say substances diffuse in and out
Supply food and oxygen and takeaway waste CO2
Only one cell thick so have a short diffusion pathway
What do capillaries join up to form
Veins
Structure of a vein
Blood pressure is lower so don’t have as thick walls
Have a large lumen to help blood flow despite the low pressure
Have valves to keep the blood flowing in the right direction
What is the rate of blood flow
The blood passing through per minute
