Blood is a fluid connective tissue.
It is 6.8 litresin man and 500ml less in woman.
6-8% of body weight (pH7.4)
Solid or cellular part called blood cells and fluid part called the blood plasma


  1. Red Blood Corpuscles (RBC)
    Also called Erythrocytes, disc-shaped (for increased surface area), no nucleus contains a pigment called Haemoglobin, which gives blood its red color.
    Average man: Amount of Haemoglobin is 14-15.6gm/100cc of blood (11 – 14 in woman)
    RBC are produced in spleen and liver in foetus and in bone marrow after birth @ 1.2 million/sec
    Life of RBC is 120 days after which they are broken down in spleen or liver. Product of breakdown of aemoglobin is a pigment (yellow colour), called bilirubin which normally disposed off through bile whereas haem transferred to red bone marrow. Retention of bilirubin leads to jaundices.
    More: Polycythemia. Less : Anaemia
  2. White Blood Corpuscles (WBC)
    Also called Leucocytes rounded, with a nucleus, far less numerous than RBCs (1:400
  • 500) (5,000-10,000/cu mm), life 3-4 days,
    soldiers of body’s defence system.
    Are of 2 types: Granulocytes (Basophils,
    Eosinophils, Neutrophils) and Agranulocytes
    (Monocytes: Lymphocytes)
    Basophils: Take up basic stains. Have an Sshaped
    nucleus. Secrete an anti-coagulant Heparih, which prevents clots within the blood vessels.
    Neutrophils: Stain equally well with both
    acidic and basic dyes. Most numerous of the
    WBCs (65-70%). Defence.
    Monocytes: Largest of all. Lymphocytes: 25% of the WBC. Takes part in antigen and antibody formation.
  1. Platelets
    Also called Thrombocytes, formed in bone marrow, about 2,50,000/cu mm of blood life 3-7days, sets off blood clotting PLASMA (65%)
    Watery part of blood, clear, yellow fluid. Contains about 90% water, proteins and orgains salts.
    Plasma contains 7% proteins which include
    Albumin, Globulin and Fibrinogen.
    Plasma transports nutrients from the small intestine to the body tissues, and return the waster material to the kidneys, where it is filtred out.
    Regulates pH of blood.
    Lymph = Blood – RBC i.e. Plasma + WBC.
    Lymph forms second circulatory sytem. It acts as middle man between blood and tissue.
    All interchanges of nutrients and waster products between blood and tissue takes place through lymph only.
    It has more of lymphocytes as compared to that of blood (Blood has more of neutrophils.)
    Spleen produces lymph. At the same time it also acts as the graveyard of lymph.
    Spleen is also known by the name of ‘Blood Bank’ because RBCs, WBCs and Lymph are produced in spleen. It is situated above left kidney behind the stomach.
    COMPARISON BETWEEN BLOOD AND LYMPH BLOOD * It is red colourdue to presence of haemoglobin in erythrocytes.
    * Circulation starts from the heart. * Act as vehicle.
    * It is colourlessdue to absence of haemoglobin.
    * Circulation starts from the tissue space.
    * Act as middle man
    Father of blood grouping Karl Landsteiner
    (Australian pathologist). He discovered A, B
    and O blood groups in 1900.
    Decastello and Sturle in 1902 discovered AB
    blood group.
    ABO system of blood groups is based on
    antigens and antibodies.
    Antigens: They are proteins and are found
    on the surface of RBC’s Antigens are A and B.
    Antibodies: They are produced in lymph glands and are present in blood plasma .
    AB: Universal receipient.
    O: Universal donor.
    RH factor: It is based on RH antigen. Discovered in 1940 by Landsteiner and A.S.Veiner. It discovered in Rhesus monkey. Rh+ can receive blood from Rh- but no viceversa.
    Blood transfusion technique was first developed by James Blundell in 1825. Blood circulation by William Harvey
    Blood grouping – by Karl Landsteiner
    Inlargerons – Antiviral proteins increases
    immunity of our body by producing
Read More  அகரவரிசைப்படி சொற்களை சீர் செய்தல் TNPSC

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