Chapter 6 Classification of Tissues Flashcards
Epithelial cell description
- the membranes always have one free surface, called the apical surface and typically that surface is significantly different from the basal surface
- cells are attached to and supported by an adhesive basement membrane
Epithelial Tissue
a sheet of cells that covers a body surface or lines a body cavity.
basement membrane
an amorphous material secreted partly by the epithelial cells (basal lamina) and connective tissue cells (reticular lamina) that lie next to each other.
Simple epithelia
consists of one layer of cells attached to the basement membrane
stratified epithelia
consisting of two or more layers of cells
squamous
less tall than wide
cuboidal
cube-like, equal height/width
columnar
more tall than wide, column-like
pseudostratified epithelium
actually a simple columnar epithelium but because its cells vary in height and the nuclei lie at different levels above the basement membrane, it gives the false appearance of being stratified. Often ciliated.
transitional epithelium
Apical side are bubbly. found only in urinary system organs subjected to periodic distension, such as the bladder.
Endocrine glands
lose their surface connection (duct) as they develop; thus they are referred to as ductless glands. They secrete hormones into the extracellular fluid, and from there the hormones enter the blood or the lymphatic vessels that weave through the glands.
Exocrine glands
retain their ducts, and their secretions empty through these ducts either to the body surface or into body cavities. the exocrine glands include sweat and oil glands, liver, and pancreas.
Simple squamous epithelium
single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia.
Simple cuboidal epithelium
single layer of cubelike cells with large, spherical central nuclei
Simple columnar epithelium
single layer of tall cells with round to oval nuclei; some cells bear cilia; layer may contain muscus-secreting unicellular glands (goblet cells)