Circulatory System Flashcards
What are the functions of blood?
Transport, defence against disease and to keep a body temperature constant
How is transport a function of blood?
Blood transports oxygen, digested foods, wastes, materials and hormones
How is defence against disease a function of blood?
The blood destroys harmful bacteria and viruses, this protects us from infection.
The blood can clot when we cut ourselves, this prevents loss of blood and keeps out harmful bacteria and viruses.
How is constant body temperature a function of blood?
Chemical reactions take place in our cells to produce heat energy, the blood carries the heat all around the body.
What is the composition of blood?
Plasma, red blood cells, white blood cells and platelets
What is the function of plasma?
Transport substances and heat
What is the function of red blood cells?
Transport oxygen
What is the function of white blood cells?
It produces antibodies to fight diseases
What is the function of platelets?
Clot the blood
What are the three main blood vessels?
Arteries, veins, capillaries
Describe a vein?
Thin wall with large lumen,
blood doesn’t flow under pressure,
has valves to prevent back flow of blood,
carries blood to the heart,
usually contains oxygen poor blood
Describe an artery
Thick wall with a small lumen,
Blood carried under high pressure,
No valves,
Carries blood away from the heart,
Usually contains oxygen rich blood
Describe a capillary
Thin wall with tiny lumen,
Blood does not flow under pressure,
No valves,
Connects arteries and veins
What is the function of the heart?
To pump blood around the body
Describe the heart’s chambers?
2 atria at the top and 2 ventricles at the bottom
