Blood components and functions: red cells, platelets, plasma

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Today, we all know that the heart is responsible for pumping blood around an organism's body and that the same blood is pumped over and over. however, for 1200 years prior to 1628, the belief was very different. it was thought that the liver made new blood, which was then pumped by the lungs around the body and "consumed" by the body's tissue.

In 1628, William Harvey used experiments to prove the following:

The heart pumps blood around the body through arteries and veins.

Blood flows in only one direction through the heart due to the presence of valves.

Blood is not consumed as nourishment for tissues, but returns to the hear to be re-pumped around the body.

Contents of the Blood

Blood plays a vital role in the transport of oxygen, carbon dioxide, nutrients and waste products around the body. Blood also helps to maintain a constant body temperature and help keep the body disease free. Not to much then!

There are different components that make up blood, each of which has a different function:

Red Blood Cells

White Blood Cells

Platelets

Plasma

Functions

The Red Blood Cell

-Carry oxygen around body to all cells.

- No nucleus allows for more room to carry oxygen.

- Disc shape allows easy flow.

-Biconcave shape increases surface over which oxygen can be absorbed.

2. The White Blood Cell

-Involved in defending the body against disease.

-Shape can change to fit through capillary walls.

-Engulfs and digest pathogens (microbes)

3. Platelets

-Fragments of cells, involved in blood clotting.

4. Plasma

-Liquid part of the blood, mostly water.

-Carries proteins like hormones, carbon dioxide, urea and other waste materials

Red Blood Cells White Blood Cells

The Smaller Cell The Larger Cell ( *2)

Definite Shape Able to Change Shape

No Nucleus Present Nucleus Present

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