JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD Pharm. D I Year HUMAN ANATOMY AND PHYSIOLOGY Previous Question Paper (October – 2020 - R08)

The cell membrane, or plasma membrane, is a semi-permeable lipid bilayer that encloses the cell contents. It is primarily composed of phospholipids, cholesterol, and integral or peripheral proteins, following the fluid mosaic model. The hydrophilic heads of the phospholipids face the aqueous environment, while hydrophobic fatty acid tails face inward. Its primary functions include regulating the transport of ions and molecules via passive diffusion, osmosis, or active transport, maintaining cellular homeostasis, and facilitating cell signaling through membrane-bound receptors.

Connective tissue is the most abundant and widely distributed tissue in the body, serving to bind, support, protect, and insulate organs. It consists of three main components: specialized cells (such as fibroblasts, adipocytes, or chondrocytes), protein fibers (collagen, elastic, and reticular fibers), and an amorphous ground substance. Based on its structure and function, it is classified into loose connective tissue (e.g., areolar, adipose), dense connective tissue (e.g., tendons, ligaments), and specialized connective tissue, which includes cartilage, bone, blood, and lymph.