Chapter 4 Flashcards
Tissues
collections of specialized cells and the extracellular substances surrounding them.
extracellular matrix
noncellular substances surrounding the cells
Histology
microscopic study of tissues.
endoderm
inner layer, forms the lining of the digestive tract and its derivatives.
mesoderm
middle layer, forms tissues such as muscle, bone, and
blood vessels.
ectoderm
the outer layer, forms the skin
neuroectoderm
portion of the ectoderm that becomes the nervous system
neural crest cells
Groups of cells that break away from the neuroectoderm during development that give rise to parts of the peripheral
nerves, skin pigment, the medulla of the adrenal gland, and many tissues of the face.
Epithelial tissue or epithelium
covers and protects surfaces, both outside and inside the body.
free or apical
surface not attached to other cells
lateral surface
attached to other epithelial cells
basement membrane
The basal surface of most epithelial tissues is attached
to a basement membrane, a specialized type of extracellular material secreted by epithelial and connective tissue cells.
Simple epithelium
consists of a single layer of cells, with each cell extending from the basement membrane to the free surface.
Stratified epithelium
consists of more than one layer of cells, but only the basal layer attaches the deepest layer to the basement membrane.
Pseudostratified columnar epithelium
special type of simple epithelium; appears to be stratified but is not; It consists of one layer of cells, with all the cells attached to the basement membrane.
Squamous
flat or scalelike.
Cuboidal cells
cube-shaped—about as wide as they are tall.
Columnar
(tall and thin, similar to a column) cells are taller than they are wide.
Nonkeratinized (moist) stratified squamous epithelium
found in mouth, esophagus, rectum, and vagina, consists of living cells in the deepest and outermost layers. A layer of fluid covers the outermost layers of cells, makes moist.
keratinized stratified squamous epithelium
found in the skin, gums and hard palate of the mouth; consists of living cells in the deepest layers, and the outer layers are composed of dead cells containing the protein keratin. The dead, keratinized cells give the tissue a dry, durable, moisture-resistant character.
transitional epithelium
type of stratified epithelium that lines the urinary bladder, ureters, kidney, urethra; structures where considerable expansion can occur/ stretch cells
goblet cells
specialized columnar epithelial cells that are responsible for secreting; found in endocrine glands; unicellular
desmosomes
disk-shaped structures with especially adhesive glycoproteins that bind cells to one another and intermediate filaments that extend into the cytoplasm of the cells
Hemidesmosomes
attach epithelial cells to the basement membrane.