is a sheet of cells that covers a body surface or lines a body cavity.
forms the outer layer of skin, dips into and lines the open cavities of the cardiovascular , digestive, and respitory systems, and covers the walls and organs of the closed ventral body cavity.
covering and lining epithelium
fashions the glands of the body
What are the six functions of the epithelium
what are the special characteristics of epithelium
supported by connective tissue
avascular but innervated
are composed of a single cell layer. typically found where absorption and filtration occur and a thin epithelial barrier is desirable
consisting of two or more cell layers stacked together. are common in high abrasion areas where protection is important , such as the skin surface and the lining of the mouth
are flattened laterally and their cytoplasm is sparse. Found where the filtration or the exchange of substances by rapid diffusion is a priority.
provides a slick friction reducing lining in the lymphatic vessels and in all hollow organs of the cardiovascular system
found in the serous membrane lining the ventral body cavity and covering the organs
consists of a single layer of cells as tall as they are wide . The spherical nuclei stain causes the cell layer to look like a string of beads. Its important function is absorption and secretion
single layer of tall closely packed cells. It lines the digestive tract form the stomach through the rectum. Mostly associated with absorption and secretion.
that secrete a protective lubricating mucus
Single layer of cells of differing heights..the cells rest on the basement membrane. It also secretes particularly of the mucus, and also absorbs.
Contains two or more cell layers. They regenerate from below. The basal cells divide and push apically to replace the older surface cells. Considered more durable than the simple epithelia. The major role is protection
is the most widespread of the epithelia. composed of several layers , it is thick and well suited for its protective role in the body. Found in areas subject to wear and tear and its surface cells are constantly being rubbed away and replaced by division of basal cells. Forms the external part of the skin and extends a short body distance into every body opening
rare in the body, mostly found in the ducts of some of the larger glands ( sweat and mammary glands).
stratified cuboidal epithelium
also has a limited distribution in the body. Small amounts are found in the pharynx, the male urethra, and some lining of the glandular ducts. ALso occurs at transitio areas between two other types of epithelium
forms the lining of hollow urinary organs, which stretch as they fill with urine. Cells at the basal level are cuboidal or columnar.