Bio science essays

Bio science essays The body is constituted of different types of cells which unite together to form contrary tissues. Tissues are a group of similar cells and their intercellular substance specialized to perform a specific function; primary tissue types of the body are epithelial, connective, muscle, and nervous tissue. Epithelial is pertaining to a primary tissue that covers the body surface, lines its internal cavities, and forms glands. The connective tissue is also a primary tissue; form and function vary extensively. Functions include support, storage and protection(Marieb, E. N., 1998, P.109) Epithelium occurs in the body as (1) covering and lining epithelium and (2) glandular epithelium. Covering and lining epithelium forms the outer layer of the skin, dips into and lines the open cavities of the cardiovascular, digestive, and respiratory systems, and shelters the walls and organs of the closed ventral body cavity. Glandular epithelium customs the glands of the body. Epithelium is broadly disseminated throughout the body; its functions are many and varied to perform specific roles. Its functions include protection, absorption, secretion, filtration, excretion and sensory reception. Protection is covering or lining the body surface both internal and external. Absorption is the process by which products of digestion pass through the alimentary tube mucosa into the blood or lymph (protein-containing fluid transported by lymphatic vessels). Secretion is 1. The passage of material formed by a cell to its exterior; 2. Cell product that is transported to the exterior of a cell. Filtration is the passage of a solvent and dissolved substances through a membrane or filter. Excretion involves elimination of waste products from the body. Sensory reception which is dendritic end organs, or parts of other cell types, specialized to respond to a stimulus(Marieb, E.N.1998, p111-116). The classification of epit...