Combustion of blood

What does blood consist of?

1. Plasma

2. Platelets

3. Red blood cells

4. White blood cells

What is plasma and what are its functions?

Plasma is a straw coloured liquid that names up just over half the volume of blood. It is used to:

• transport CO2 from respiring cells to the lungs

• transport digested food from the small intestine to respiring cells

• transport urea from the liver to the kidney

• distribute heat all around the body

• transport hormones from the glands where they are made to target organs

What are platelets and what do they do?

They are tiny fragments of cells and are involved in helping blood clotting and scabs forming which prevents blood lost and pathogens (bacteria) entering.Platelets are able to:

• release chemicals that cause soluble proteins to form a mesh of insoluble fibres across the wound

• stick together to form clots producing a scab or blockage to prevent microbes entering the body

What do red blood cells do?

Red blood cells transport oxygen. They absorb the oxygen from the lungs and transport it through narrow blood vessels. Some adaptions are:

• contains haemoglobin which is a red protein that combines with oxygen

• no nucleus meaning more space

• small & flexible so it can fit through narrow vessels.

• biconcave shape which means more surface area for oxygen.

What do white blood cells do?

White blood cells defend the body against disease. There are multiple types of blood cells but we can divide them into two types: Phagocytes (find foreign bodies) and Lynphocytes (produce antibodies).The phagocytes engulf the bacterial cell. The bacterial cell is then broken down by enzymes. This is called phagocytosis.

Some adaptions of white blood cells are:

• an irregular shape to squeeze out blood vessels and get to the site of the infection.

What is the composition of blood + what are they made from?

Plasma - 55%

Red blood cells - 45%

White blood cells - >1%

Platelets - >1%

All of them are made in bone marrow.