Epithelium in anatomy, is a layer of cells that serves as a protective covering over some surface, such as the outside of an organ or the lining of the wall of a cavity in the body. Epithelial cells generally have large nuclei, clear outlines, and a large amount of granular protoplasm. Some, called columnar, are long and narrow and may, as in the respiratory tract, have hairlike cilia extending from the outer surface. The skin contains several layers of epithelial cells, with columnar cells at the bottom, squamous cells at the top, and cuboidal cells in middle layers. Many of the secretory glands are composed of epithelial cells as are some of the endocrine glands.
Online Encyclopedia Blog For Kid's Research In Sciences, Health, Environment and Technology
Showing posts with label Epithelium. Show all posts
Showing posts with label Epithelium. Show all posts
Subscribe to:
Posts (Atom)
Popular Posts
-
Cellular Respiration, process in which cells produce the energy they need to survive. In cellular respiration, cells use oxygen to break d...
-
Sense Organs, in humans and other animals, faculties by which outside information is received for evaluation and response. This is accompli...
-
. Respiratory System, in anatomy and physiology, organs that deliver oxygen to the circulatory system for transport to all body cells. Oxyge...
-
Reproductive System, term applied to the group of plant or animal organs that are necessary for or that are accessory to the reproductive pr...
-
Hypothalamus, part of the brain, important in regulating the internal activities of the body. Although the hypothalamus constitutes less th...