Human Blood

Human Blood

» Blood is a fluid connective tissue.
» The quantity of blood in the human’s body is 7% of the total weight.
» This is a dissolution of base whose pH value is 7.4.
» There is an average of 5 – 6 litters of blood in human body.
» Female contains half liter of blood less is in comparison to male.

Blood is consist of two parts :
1. Plasma
2. Blood corpuscle

1. Plasma

This is the liquid part of blood. 60% of the blood is plasma.
Function of plasma : Transportation of digested food, hormones, exeretory product etc from one part of the body to another part.

Serum : When Fibrinogen and protein is extracted out of plasma, the remaining plasma is called serum.

2. Blood corpuscles

This is the remaining 40% part of the blood. This is divided into three parts -

1. Red Blood Corpuscles (RBC)
» Red Blood Corpuscles (RBC) of a mammal is biconcave.
» There is no nucleus in it. Exception - Camel and Lama RBC is formed in Bone marrow. (At the embroynic stage its formation takes place in liver).
» Its life span is from 20 days to 120 days.
» Its destruction takes place in liver and spleen. Therefore, liver is called grave of RBC.
» It contains haemoglobin, in which haeme is iron containing compound and due to this the colour of blood is red.
» Globin is a proteinous compound. With haeme it is extremely capable of combining with oxygen and carbon dioxide.
» The iron compound found in haemoglobin, as haematin.
» The main function of RBC is to carry oxygen from the lung to all cells of the body and bring back the carbon dioxide.
» Anaemia disease is caused due the deficiency of haemoglobin.
» At the time of sleeping RBC reduced by 5% and people who are at the height of 4200 meters RBC increases by 30% in them.
» Number of RBC is measured by an instrument called hemocytometer.

2. White Blood Corpuscles (WBC) or Leucocytes » In shape is similar to Amoeba.
» Its formation takes place in Bone marrow, lymph node and sometimes in liver and spleen.
» Its life span is from 2 to 4 days.
» Nucleus is present in the White Blood Corpuscles.
» Its main function is to protect the body from the disease.
» The ratio of RBC and WBC is 600 :1.
» About 60 to 70% part of WBC is made up of neutrophile corpuscles which help in engulfing disease causing microorganism and bacteria.

3. Blood Platelets or Thrombocytes
» It is found only in the blood of human and other mammals.
» There is no nucleus in it.
» Its formation takes place in Bone marrow.
» Its life span is from 3 to 5 days.
» It dies in the spleen.
» Its main function is to help in clotting of blood.
» In dengue fever number of platelets reduced.