Blood

Def­i­n­i­tion of blood :

Blood is flu­id that tech­ni­cal­ly con­sid­ered a con­nec­tive tis­sue. Nor­mal­ly blood has a pH of 7.4 . Aver­age adult has about 4 5 — 5.5 liters of blood cir­cu­lat­ing inside the body through arter­ies , veins and cap­il­lar­ies. It includes plas­ma (liq­uid part) , blood cells ( RBC, WBC , Platelets). RBC trans­port oxy­gen to the tis­sues . WBC pro­tect our body against infec­tion. Platelets helps stop bleed­ing. Plas­ma which sus­pend­ed all these cells car­ries pro­tein, min­er­als, elec­trolytes and waste products. 

Func­tion of blood : 

1. Trans­porta­tion : The blood deliv­ers oxy­gen from the lungs to the cells of the body and trans­port meta­bol­ic waste (Co2) prod­ucts away from the same cells. 
2. Sup­ply nutri­ents such as glu­cose, amino acid and fat­ty acids. 
3. Immuno­log­i­cal func­tion includ­ing cir­cu­la­tion of white blood cells, detec­tion of for­eign bodies. 
4. Con­trol coag­u­la­tion mechanisms. 
5. Mas­sen­ger func­tion ( trans­port hormones).
6. Reg­u­la­tion of body temperature.

Com­po­si­tion of blood: 

Blood con­sist 55% plas­ma. 45% cel­lu­lar ele­ments. RBC’s are 41% WBC and platelets 04%. Plas­ma con­sists most­ly of water with pro­teins , glu­cose, ions, nutri­ents and waste mixed in.