Chapter 4 Section 2 Vocab

ciliated simple columnar epithelium

an epithelial tissue which has cells with cilia at its apical surface & goblet cells; this tissue is found in the respiratory tract.

pseudostratified nonciliated columnar epithelium

an epithelial tissue which has no cilia or goblet cells.

fibroblasts

large, flat cells with branching processes which are present in several connective tissues; they secrete fibers and certain components of the ground substance of the extracellular matrix.

exocrine glands

secrete their products into ducts that empty onto the surface of a covering & lining epithelium such as the skin or the lumen of a hollow organ.

merocrine glands

secretions are synthesized on ribosomes attached to rough ER; processed, sorted & packaged by the Golgi complex; and released from the cell in secretory vesicles via exocytosis.

unicellular glands

single-celled such as goblet cells which secrete directly onto the apical surface of a lining epithelium.

mesothelium

the simple squamous epithelium which forms the epithelial layer of the serous membranes.

compound gland

a gland which has a duct that branches.

simple gland

a gland whose duct does not branch.

apocrine glands

accumulate their secretory product at the apical surface of the secreting cell; then that portion of the cell pinches off from the rest of the cell to release the secretion; the remaining part of the cell repairs itself & repeats the process.

holocrine glands

accumulate their secretory products in their cytosol; as the secretory cell matures it ruptures & becomes the secretory product; the sloughed off cell is replaced by a new cell (sebaceous glands of the skin).

stratified cuboidal epithelium

an epithelial tissue having 2 or more layers of cells of which the cells in the apical layer are cube-shaped; function is protection & limited secretion & absorption.

stratified columnar epithelium

an epithelial tissue having several layers of irregularly shaped cells; the apical cells are columnar; its function is protection & secretion.

keratinized stratified squamous epithelium

an epithelial tissue in which cells in the apical layer are flat; those of the deep layers vary from cuboidal to columnar; the basal cells undergo cell division & are pushed upward toward the apical layer where they dehydrate and contain a layer of keratin (a tough, fibrous protein).

nonkeratinized stratified squamous epithelium

an epithelial tissue in which cells in the apical layer are flat; those of the deep layers vary from cuboidal to columnar; the basal cells undergo cell division & are pushed upward toward the apical layer; this tissue does not contain keratin in the apical layer and remains moist; found lining the mouth & esophagus.

transitional epithelium

an epithelial tissue in which the cells in apical layer range from squamous (when stretched) to cubiodal (when relaxed); its function is to permit distension.

pseudostratified ciliated columnar epithelium

an epithelial tissue in which the cells that extend to the surface have cilia or secrete mucus (goblet cells).

cuboidal cells

are as tall as they are wide and are shaped like cubes or hexagons; they may have microvilli at their apical surfaces & function in either secretion or absorption.

columnar cells

are much taller than they are wide, like columns, & protect underlying tissues; their apical surfaces may have cilia or microvilli; they are often specialized for secretion and absorption.

squamous cells

arranged like floor tiles & are thin, which allows for the rapid passage of substances through the cells.

transitional cells

change shape, from flat to cuboidal & back as organs such as the urinary bladder stretch to a larger size and then collapse to a smaller size.

multicellular glands

composed of many cells that form a distinctive microscopic structure or macroscopic organ; their ducts may be branched or unbranched; their secreting portions may be tube shaped or flask shaped.

macrophages

develop from white blood cells called monocytes; they are cells with an irregular shape & short branching projections; they can engulf bacteria & cellular debris by phagocytosis.

microvilli

finger-like cytoplasmic projections which increase the surface area of the plasma membranes of cells.

goblet cells

modified columnar epithelial cells that secrete mucus, a slightly sticky fluid, at their apical surfaces; the cells are shaped like a goblet or wine glass.

adipocytes

store triglycerides (fats); the are found deep to the skin and around organs such as the heart and kidneys; they are also called adipose cells.

extracellular matrix

the material located between the widely spaced cells in connective tissues.

endothelium

the simple squamous epithelium which lines the heart, blood vessels, lymphatic vessels.

simple cuboidal epithelium

the tissue in which cell nuclei are usually round and centrally located; it is found in organs such as the thyroid gland & kidneys where it performs the functions of secretion & absorption.

simple columnar epithelium

the tissue in which cells appear like columns (taller than they are wide); cell nuclei are oval & located near the basal surface of the cells.

simple squamous epithelium

the tissue in which the nucleus of each cell is a flattened oval or sphere and is centrally located; found at sites where the processes of filtration (blood in kidneys) or diffusion (oxygen into capillaries) occur; this tissue is NOT found in body areas that are subject to mechanical stress (wear & tear).

nonciliated simple columnar epithelium

the tissue which contains 2 types of cells: ones with microvilli at their apical surfaces & goblet cells.

mast cells

white blood cells that are abundant along blood vessels that supply connective tissue; they produce histamine which is part of the body's inflammatory reponse; they can also bind to, ingest, & kill bacteria.