Epithelial Tissue Flashcards
What is Epithelium?
a type of body tissue that forms the covering on all internal and external surfaces of your body, lines body cavities and hollow organs and is the major tissue in glands
name 2 types of epithelium.
lining
glandular
give some Functions of Epithelium.
Epithelium creates a selective barrier
between the external environment and the
underlying connective tissue.
* secretion
* absorption,
* transportation,
* protection,
* receptor function
classify epithelium based on cell shape.
Squamous = flat
Cuboidal = cube
Columnar = rectangular (column)
Transitional = ability to change shape
classify epithelium based on cell layers.
Simple = one layer
Stratified = more than one layer
Pseudostratified = false layered (appears to be more than one
layer, but only one);
what are ciliated cells?
Ciliated cells have cilia on their free surface that help to move substances
what are Secretory cells?
they secrete substances onto the surface of cell sheet
define basement membrane.
thin, dense layer of extracellular matrix that lines most human tissues forming the supporting structure
name the 2 laminas, basement membrane is made up of?
basal lamina, reticular lamina
what is Simple squamous epithelium
- a single layer of thin, flattened cells
- easily damaged
what is Simple squamous epithelium involved in?
filtration, diffusion,
osmosis,
what is Simple cuboidal epithelium
single layer of cube-shaped cells
what is Simple cuboidal epithelium involved in?
secretion and absorption
what is Simple columnar epithelium
single layer of cells that are longer than they
are wide
what is Simple columnar epithelium involved in?
- ciliated or nonciliated
- some have microvilli
- goblet cells = secrete mucus
- absorption, secretion, protection
what is Pseudostratified columnar
epithelium
“Pseudostratified” is a term applied to epithelia that
appear to be stratified (because have nuclei at various
levels), but in which all component cells reach the base of
the epithelium and are attached to the underlying
basement membrane.
what is Pseudostratified columnar
epithelium involved in?
secretion of mucus, propulsion pf mucus by ciliary action
what is Stratified squamous epithelium?
- many layers of flattened cells
what is Stratified cuboidal epithelium?
2 or 3 layers of cuboidal cells
transitional epithelium can change shape, stretch and distend. true or false?
true
what is Epithelial Metaplasia?
Definition. A morphologic finding that refers to the replacement of a group of one type of epithelial cells (e.g., glandular epithelial cells) to another type of epithelial cells (e.g., squamous epithelial cells).
name apical specializations?
microvilli
stereocilia
cilia
what are microvilli?
Fingerlike cytoplasmic projections
microvilli increase the surface area for absorption. True or false?
true
give the structure of microvilli
The internal structure of microvilli contains a core
of actin filaments that are cross linked by several
actin bundling proteins (fimbrin)
what are stereocilia?
microvilli of unusual length
what are cilia?
cytoplasmic processes containing bundle
of microtubules.
classify cilia?
- Motile cilia
- Primary cilia (monocilia)
- Nodal cilia
