Composition and Functions of Blood Question And Answers

Question 1. Discuss the composition and functions of blood.
Answer: 

Compsotion of blood:

1. Formed elements – blood cells – 45%.
   1. Erythrocytes or red blood corpuslces (RBC’s)
      • Normal count -5 million/ul
   2. Leucocytes or white blood corpuscles (WBC’s)
      • Normal count – 4,000 – 11,000/μl
   3. Platelets or thrombocytes.
      • Normal count – 1.5-4 lacs/ul
2. Plasma-55%.
   • It is a clear, straw colored fluid portion of the blood.
   • It contains.
     1. 91-92%-water.
     2. 8-9% solids.
        1. 1% inorganic molecules.
           \(-\mathrm{Na}^{+}, \mathrm{Ca}^{2+}, \mathrm{K}^{+}, \mathrm{Mg}^{2+}, \mathrm{Cl}^{-}, \mathrm{HCO}_3^{-}, \mathrm{PO}_4^{3-}, \mathrm{Fe}^{2+}, \mathrm{Cu}^{2+}\)
        2. 8% organic molecules.
           • Plasma proteins – albumin, globulin, fibrinogen. Amino acids- essential and non-essential.
           • Carbohydrates – glucose.
           • Fats – triglycerides, cholesterol, phospholipids. Internal secretions – esterase
           • Nonprotein nitrogenous substances – ammonia. Antibodies.
     3. Gases:
        • Oxygen, carbon dioxide, nitrogen.

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Functions of blood:

1. Nutritive.
   • Blood carries the food absorbed from the digestive system to tissues for growth and production of energy.
2. Respiratory.
   • Blood transport oxygen from lungs to the tissues and carbon dioxide from the tissues to the lungs.
3. Excretory.
   • Waste products are carried through blood to excretory organs like kidney, skin and intestine.
4. Transport of hormones and enzymes.
   • Blood transports the hormones secreted from the endocrine glands to their target organs/tissues.
   • Blood also transports enzymes.
5. Regulation of water balance.
   • Water balance is regulated as the water content of the blood gets interchangeable with interstitial fluid.
6. Regulation of acid base balance – pH.
   • Blood maintains pH through the buffering system of plasma proteins and haemoglobin.
   • This mechanism is called homeostasis.
7. Regulation of body temperature.
   • Blood regulates body temperature due to its high specific heat.
   • It regulates through thermoregulatory mechanism due to which balance occurs between heat loss and heat gain in the body.
8. Storage function.
   • Blood stores substances like proteins, glucose, sodium and potassium so that these substances can be used during starvation, fluid loss, etc.
9. Defensive function
   • White blood cells help in the defense of the body.

Read And Learn More: BDS Previous Examination Question And Answers

Question 2. Give the composition of blood and write about the importance of plasma.
Answer:

Plasma: