Blood is such an important connective tissue, which accomplishes various important processes in the human organism. It carries out oxygen, nutrients, and hormones and eliminates wastes of the metabolic process. Blood ensures homeostasis since it is composed of plasma as well as formed elements, including RBCs, WBCs and platelets. Transfusions are made safe depending on its classification into various blood groups. The knowledge of the components and functions of blood is important in respect to health and medical science.

Key Highlights for RAS Mains

1. Blood constituents

A. Plasma (55 % Blood Volume)

• Yellowish-brown viscid liquid containing 90-92 % water.
• Contains proteins:
  • Fibrinogen- assists in blood clotting.
  • Globulins- immune protection.
  • Albumins- maintains osmotic balance.
• It also comprises minerals (Na +, Ca ++, Mg ++, HCO 3 -), nutrients, hormones and wastes.
• Serum = non-clotting factors of plasma.

B. Elements of Form (45%)

Comprising RBCs, WBCs and Platelets.

i. Erythrocytes (RBCs)

• Most plentiful; biconcave, lacking a nucleus in the case of mammals.
• Carry oxygen (haemoglobin 12-16 g/100ml).
• Life span: approximately 120 days; killed in the spleen (RBC graveyard).

ii. Leucocytes (WBCs)

• Nucleate and fewer in abundance.
• Two categories:
  • Granulocytes:
    • Neutrophils (60 - 65%): Phagocytic, destroy microbes.
    • Eosinophils (2-3%): Combats Allergies and infections.
    • Basophils (0.5-1%): Secret stam, heparin (inflammation).
  • Agranulocytes:
    • Lymphocytes (20-35%): B & T cells to respond to an immune response.
    • Monocytes (6-8 %): scrappy cells.

iii. Platelets (Thrombocytes)

• Megakaryocytes cell fragments.
• Assistance in coagulation, low numbers leads to a bleeding disorder.

Blood Groups

A. ABO Gruplama

• Depending on red blood cells antigens (A, B) and plasma antibodies.
• Blood Type is classed as A, B, AB or O.

B. Universal Donor And Recipient

• O group: Universal donor (no antigene).
• AB group: Universal donor (no anti-bodies).

ABO Compatibility Table

Rh Antigen, and Blood Transfusion

• Rh+ (positive): Rh antigen: ~80 percent of human beings.
• Rh Rh- (negative): Absent Rh antigen; this person would develop antibodies were exposed.
• In Pregnancy Rh Incompatibility
• In case Rh+-baby has Rh- mother:
• First pregnancy: Nothing to worry about (the placenta shields).
• Subsequent pregnancies: There is a risk of destruction of fetal RBCs, of Erythroblastosis Foetalis, by mother antibodies.
• Prevention: Anti-Rh administration upon the first delivery.

Lymphatic System

• Interstitial Fluid: Solutes and water of capillaries move into tissue space.
• Lymph: Interstitial fluid that has been accumulated, colourless, it comprises lymphocytes.
• Functions:
  • Immunity through the lymphocyte.
  • Nutrient, hormones and fats transport (through lacteals, which are present in villi).
  • Restores fluid balance by re-circulating fluid.

Conclusion for RPSC

Physiologically, blood is irreducible and disease-preventative. It is possible to comprehend essential medical processes with the knowledge of its parts, compatibility of the bloodgroups, and functions of the lymphatic system. Safe Healthcare delivery requires proper transfusion and recognition of Rh factors.

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