The Circulatory System
Function of Blood
Transport oxygen to the cells
Transport food to the cells
Transport waste material away from cells
Help fight infection
Help keep the body at the right temperature
Composition of Blood
Blood is a type of tissue because it is made up of similar cells that work together
Blood is made up of straw-coloured liquid called plasma
3 types of blood float in plasma: red blood cells - white blood cells - platelets
Blood Vessels
Blood vessels carry the blood around the body
There are three types of blood vessels: arteries - veins - capillaries
Arteries have thick walls that are very strong. Blood will not flow backwards in arteries because there is pressure coming from the heart
Veins have thinner walls and are easier to damages. Veins always carry blood towards the heart
Capillaries have walls that are only one cell thick. They are extremely thin as they need to weave through the organs to deliver substances to cells
The Heart
The heart is an organ made of a unique type of muscle known as cardiac muscle
It is approximately the size of a human fist.
It's function is to pump oxygenated blood all around the body. It also sends deoxygenated blood to the lungs to remove carbon dioxide and collect oxygen