- 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 litres of blood in human body.
- Female contains half litre of blood less in comparison to male.
- Blood consists of two parts:- (A) Plasma (B) Blood Corpuscles
- This is the liquid part of blood. 60% of the blood is plasma. Its 90% parts is water, 7% protein, 0.9% salt and 0.1% is glucose. Remaining substances are in a very low quantity.
- Function of plasma - Transportation of digested food, hormones, excretory product etc. from the body takes place through plasma.
- Serum - When Fibrinogen & Protein is extracted out of plasma, the remaining plasma is called serum.
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 & spleen. Therefore, liver is called grave of RBC.
- It contains haemoglobin, in which haeme iron containing compound is found and due to this the colour of blood is red.
- Globin is a proteinous compound which is extremely capable of combining with oxygen and carbon dioxide.
- The iron compound found in haemoglobin, is haematin.
- The main function of RBC is to carry oxygen to all cells of the body and bring back the carbon dioxide.
- Anaemia disease is caused due to the deficiency of haemoglobin.
- At the time of sleeping RBC is reduced by 5% and people who are at the height of 4200 metres RBC increases by 30% in them.
2. White Blood Corpuscles (WBC) or Leucocytes
- In shape and constitution this is similar to Amoeba.
- Its formation takes place in Bone Marrow, lymph node and sometimes in liver and spleen.
- Its life span is from 1 to 2 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.
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.
Function of Blood:
- To control the temperature of the body and to protect the body from diseases.
Clotting of blood.
- Transportation of oxygen, Carbon dioxide, digested food, conduction of hormones etc.
- To help in establishing coordination among different parts.
Blood Group of Human
- Blood group was discovered by Lansteiner in 1900.
- For this, he was awarded with Nobel Prize in the year 1930.
- The main reason behind the difference in blood of human is the glyco protein which is found in Red Blood Corpuscles called antigen. Antigen are of two types- Antigen A and Antigen B.
- On the basis of presence of Antigen or Glyco Protein, there are four group of blood in human:
- That contains Antigen A - Blood Group A.
- That contains Antigen B- Blood Group B.
- That contains both the Antigen A and B - Blood Group AB.
- That contains neither of the Antigens- Blood Group O.
- An opposite type of protein, is found in
blood plasma. This is called antibody. This is also of two types-
Antibody "a" and Antibody "b".
Blood Group O is called the Universal Donor because it does not contain any antigen.
Blood Group AB is called Universal Receptor because it does not contain any antibody