What Are The Functions Of Blood?

All tissues need an adequate supply of blood, which depends on a normal arterial blood pressure being maintained.  In a lying position the blood pressure in the body is level, but when sitting or standing the blood to the brain has to be pushed uphill.

The brain in particular needs a continuous adequate supply of blood; if deprived of blood for longer than 3 to 4 minutes, irreversible changes take place and some brain cells die.  Therefore in cardiac arrest from any cause, urgent immediate treatment is essential to get the heart acting again.  Even in a simple faint, such as may be caused by emotional or physical strain a fall in blood pressure diminishes the blood supply to the brain. Besides this blood also functions as:

1. Acts as the transport system of the body, conveying all chemical substances, oxygen and nutrients required for the nourishment of the body in order that its normal functions mat be fulfilled, and carrying away carbon dioxide and other waste products.
2. The red blood cells convey oxygen to the tissues and remove some of the carbon dioxide.
3. The white blood cells provide any of the protective substances and by phagocytic action some of the cells protect the body against bacteria.
4. The plasma distributes proteins needed for tissue formation; it services the tissue fluid by which all cells receive nourishment; and form the vehicle by which the waste matter is conveyed to the various excretory glands for elimination.
5. The internal secretions, hormones, and enzymes are conveyed from organ to organ by means of the blood.

Main function of blood is to carry oxygen and hormones to all the cells in the body, and to carry waste products back to the liver and kidneys for filtering and removal fro the body.

All tissues are needed the blood