JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B. Pharmacy I Year HUMAN ANATOMY AND PHYSIOLOGY - II Previous Question Paper (July/August -2021 - R17)

Blood is a specialized connective tissue consisting of formed elements suspended in a liquid matrix called plasma. Its physical characteristics include a slightly alkaline pH (7.35 to 7.45), a temperature of approximately 38°C, and a viscosity 4.5 to 5.5 times greater than that of water. In an average adult, the total blood volume ranges from 5 to 6 liters.

The components of blood are divided into two main categories:

1. Plasma: Comprises about 55% of blood volume. It is a straw-colored liquid consisting of 91.5% water and 8.5% solutes, including plasma proteins (albumins, globulins, and fibrinogen), nutrients, gases, electrolytes, hormones, and waste products.
2. Formed Elements: Comprise about 45% of blood volume and include:
   • Erythrocytes (Red Blood Cells): Biconcave discs containing hemoglobin, responsible for oxygen transport.
   • Leukocytes (White Blood Cells): Nucleated cells involved in immune defense, categorized as granulocytes (neutrophils, eosinophils, basophils) and agranulocytes (lymphocytes, monocytes).
   • Thrombocytes (Platelets): Cell fragments essential for the process of hemostasis and blood clotting.

Blood performs several vital physiological functions essential for maintaining homeostasis:

1. Transportation: Blood acts as the primary transport medium, carrying oxygen from the lungs to body cells and carbon dioxide from cells to the lungs. It also transports nutrients from the digestive tract, hormones from endocrine glands, and metabolic waste products to the kidneys and liver for excretion.
2. Regulation: It helps regulate body pH through various buffer systems, adjusts body temperature by absorbing and distributing heat, and maintains water balance in cells through the osmotic pressure exerted by plasma proteins.
3. Protection: Blood provides defense against disease through the action of white blood cells (phagocytosis and antibody production). Furthermore, it prevents excessive fluid loss following injury through the clotting mechanism, which involves platelets and clotting factors.