Sunday, 5 February 2017

Notes on Human Blood for competitive exams

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 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

(A) Plasma

  • 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.
(B) Blood Corpuscles (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 & 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