Blood circulation in the body
The plasma is made up of water which contains salts, hormones and food nutrients while the blood cells which are produced in the bone marrow are red blood cells, white blood cells and platelets, each serving their own functions.
After being pumped away from the heart, the blood passes through certain vessels which branch repeatedly to form capillaries when they reach the cells and tissues of the body.
The blood is very important for life because it serves many functions. It circulates within the body delivering oxygen, digested food nutrients and hormones to the cells and tissues and taking away excretory products from them for excretion.
Therefore, these body parts exchange materials with the blood closer to them simply by diffusion. These parts of the include:
This is the external layer of the skin. Underlying this layer is the dermis. The blood does not reach the epidermis, it stops in the dermis and exchange of materials occurs between it and the epidermis.
They are flexible tissues found in various parts of the body where flexibility is needed. They are also found in movable joints where they prevent friction between the bones in contact. They are also avascular.
The cornea is the outermost front part of the eyes. Oxygen and nutrients diffuse directly from the aqueous humour and the tear fluid to the cornea because blood vessels do not reach there directly.
4. Nails and Hairs
They are modified parts of the epidermis and also receive their nutrients and oxygen from the blood vessels in the dermis.
This is the outermost part of the teeth. It is the hardest substance in the body and does not contain nerves and blood vessels.
Now, check out the meaning of some strange terms used in the article.
Definition of some terms
1. Antibodies – chemicals that destroy harmful microorganisms such as bacteria.
2. Antitoxins – chemicals that neutralize poisonous substances in our body.
3. Avascular – containing no blood vessels.
4. Capillaries – these are the smallest blood vessels formed where exchange of materials between the blood and the body cells take place.
5. Dermis – The thick deeper layer of the skin below the epidermis.
6. Engulfing – ingesting or taking in
7. Excretory products – waste metabolic products in the body.
8. Hormones – These are fluids that are produced and released by some glands, transported through the blood to reach the target organs where they elicit certain functions.