Epithelial Tissue Terms Flashcards
Covers body surfaces and lines hollow organs, body cavities, and ducts; it also forms glands. Allows the body to interact with both its internal and external environments
Epithelial Tissue
Detects changes in a variety of conditions inside and outside the body and responds by generating electrical signals called nerve impulses that activate muscular contractions and glandular secretions
Nervous Tissue
Contact points between the plasma membranes of tissue cells
Cell junctions
Weblike strands of transmembrane proteins that fuse together the outer surfaces of adjacent plasma membranes to seal off passageways between adjacent cells
Tight junctions
Contain plaque, A dense layer of proteins on the inside of the plasma membrane that attaches both to membrane proteins and two microfilaments of the cytoskeleton
Adherens junctions
Transmembrane glycoproteins that join the cells. Each one inserts into the plaque from the opposite side of the plasma membrane, partially crosses the intercellular space, and connects to cadherins of an adjacent cell
Cadherins
Encircle the cell similar to the way a belt encircles your waist
Adhesion belts
Contain plaque and have transmembrane glycoproteins that extend into the intercellular space between adjacent cell membranes and attach to one another
Desmosomes
Resemble desmosomes, but do not link adjacent cells
Hemidesmosomes
On the inside of the plasma membrane, Attach to intermediate filaments made of the protein keratin. On the outside of the plasma membrane, attach to the protein laminin which is present in the basement membrane
Integrins
Allow The cells in a tissue to communicate with one another; also enable nerve or muscle impulses to spread rapidly among cells a process that is crucial for the normal operation of some parts of the nervous system and for the contraction of muscle in the heart gastrointestinal tract and uterus
Gap junctions
Membrane proteins that form tiny fluid filled tunnels that connect neighboring cells
Connexins
Consist of cells arranged in continuous sheets, in either single or multiple layers; serves as a selective barrier that limits or is the transfer of substances into and out of the body; a secretory surface that releases products produced by cells onto its free services; a protective services that resist the abrasive influences of the environment
Epithelial tissue/epithelium
Faces the body surface, body cavity, the lumen of an internal organs or a tubular duct that receives cell secretions; May contain cilia or microvilli
Apical surface
Face the adjacent cells on either side may contain tight junctions, adherens junctions, desmosomes, and/or gap junctions
Lateral surfaces
Surfaces of the deepest layer of epithelial cells adhere to extracellular materials such as the basement membrane
Basal surface
Thin, extracellular layer that only consist of two layers the basil lamina and reticular lamina; contains proteins such as laminin and collagen as well as glycoproteins
Basement membrane
Relying on the blood vessels of the adjacent connective tissue to bring nutrients and remove waste
Avascular
One of the two types of epithelial tissue; Makes up the secreting portion of glands such as the thyroid gland, adrenal glands and sweat glands
Glandular epithelium
One of the two types of epithelial tissue; Forms the outer covering of the skin and some internal organs; also forms the inner lining of blood vessels, ducts and body cavities in the interior of the respiratory digestive urinary and reproductive systems
Covering and lining epithelium
The production and release of substances such as mucus, sweat, or enzymes.
Secretion
Intake of fluids or other substances such as digested food from the intestinal tract
Absorption
Arrangement of layers
Simple, pseudostratified, and stratified
Cell shape
Squamous, cuboidal, columnar
May consist of a single cell or a group of cells that secrete substances into ducts, onto a surface, or into the blood in the absence of ducts
Gland
Called hormones, enter the interstitial fluid and then diffuse directly into the bloodstream without flowing through a duct
Endocrine glands
Secrets their products into ducts that empty onto the surface of a covering and lining epithelium such as the skin surface or the lumen of a hollow organ
Exocrine glands
Single-celled glands. Goblet cells are an important kind of these because they secrete mucus directly onto the apical surface of a lining epithelium
Unicellular glands
Composed of many cells that form a distinctive microscopic structure or macroscopic organ. Ex.) sweat, oil, and salivary glands
Multicellular glands
Duct that does not branch
Simple gland
duct branches
Compound gland
Glands with tubular secretory parts
Tubular glands
Ducts with rounded secretory portions
Acinar glands
Ducts that have both tubular and more rounded secretory parts
Tubuloacinar glands
Synthesized on ribosomes attached to Rough ER; processed, sorted, and packaged by the Golgi complex; released from the cell with exocytosis
Merocrine glands
Accumulate their secretory product at the apical surface of the secreting cell; that portion of the cell pinches off with exocytosis from the rest of the cell to release secretion. Cell repairs itself and repeats process
Apocrine glands
Accumulate a secretory product in their cytosol
Holocrine glands
