Unit :- Blood ( Part :- 1 )

 Circulatory system ( Blood formation , composition , blood group , blood congumation ) circulatory and lymphatic system

The circulatory system

Blood is a fluid , connective tissue. It's circulates continually around the body. It provide one of the means of communication between the cells of different parts of the body and external environment.

Composition and formation of Blood

Physical properties of blood

1- Amount :- 

Blood consititue about 7 - 9 Percent of total body weight .

Colour :-

Red colour due to presence of hemoglobin (red pigment) 

Viscosity :-

3.5 - 5.4 . It is thicker z heavier and viscous than water.

Power of hydrogen ion ( P.H. value ) :- 

It is slightly alkaline it pH between 7.35 to 7.45 . 

Temperature :- 

Temperature of blood 38°C ( 100.4°F ) .

Composition of blood

Plasma normally constitute about 55% and cells about 45% of blood volume . 

Plasma :- 

The constituent of plasma are water are dissolved substance including —

1.  Plasma proteins 

2.  Inorganic salts 

3.  Nutrients 

4.  Waste materials 

5.  Hormones

6.  Gases 

Plasma proteins :- 

Plasma proteins make about 7% of plasma and they are normally retained in the blood because they are too big to escape through the capillaries pores into the tissues. They are responsible for creating osmosis pressure of blood. Normal osmosis pressure is 25 mm of Hg which keeps plasma fluid within recirculation plasma viscosity is due to plasma protein mainly aluvin , globin and fibrogen

 Aluvin :- 

These are formed in the liver . There are functions is to maintain normal plasma osmosis pressure. Alumin also act as carrier molicules for lipid and hormones.

Globin :- 

It's formed in liver and they remains in lymphoid tissue. There are functions are –

1. As antibodies 

2. Transportation of some hormones and minerals salts. 

3. Inhibition of proteolytic enzymes. 

Clothing factors :- 

These are substances essential for formation conglation of blood. Serum is plasma from which clotting factor have been removed fibrogen is synthetic in the liver and is essential for blood congumation.

Inorganic salts :- 

These are involved is an wide variety of activities including muscle contraction, transmission of nerve impulses , formation of secretion and maintenance of acid based balanced. The pH of blood is 7.35 - 7.45 . 

Nutrients :- 

In the alimentary canal food is broken down into small pieces. Ex. Mono - saccharides , amino acid , fatty acids and glycerol are absorbed. Together with minerals salts they are required by all body cells to provide heat , energy , material for repair and replacement and for the synthesis of other blood components and body secreation.

Waste products :- 

Urea  creatinine , uric acid are the waste products of protein metabolism. They are formed in the liver and conveyed in blood to the kidney for secretion.

Hormones :- 

These are substances synthesized by endocrine glands. Hormones pass directly from the endocrine cells into blood which transport them to their target cells. 

Gases :- 

Oxygen , CO² and nitrogen and transportated around the body dissolved in plasma . O² and CO² are also transporter in combination with haemoglobin in blood cells. Nitrogen is present in plasma but it has no physiological functions.