Epithelial Cells Flashcards
Purpose of epithelium
Covers body surfaces , lines body cavities and lines hollow organs.
Functions of epithelium
Protection, absorption, secretion, excretion, filtration, and diffusion are all functions of epithelium.
Basement Membrane
composed of carbohydrates and proteins which are secreted by the epithelial cells and connective tissue cells
Epitheliod Tissue
If a tissue is composed of tightly packed epithelial-like cells, but it does not have a free surface.
Example of epithelium tissue
parenchyma of the adrenal gland
Simple gland
unbranched duct
Compound duct
branched duct
Tubular gland
The secretory portion of a gland is shaped like a tube
Alveolar /Acinar
Secretory portion of a gland is shaped like a flask
Cilia
hair like surface modification seen on some epithelia. Cilia are made of microtubules
Stereocilia
Very long microvilli. Stereocilia are seen in the epididymis and the hair cells of the ear.
Microvilli
finger like projections seen on the surface of some cells. Microvilli form the brush border (striated border).
Keratinization
-seen in the epidermis
Transitional Epithelium
- domed shaped cells on the apical surface
- can be distended or stretched
Examples of transitional epithelium
Bladder and urinary tract
Examples of pseudostratifed columnar epithelium
-lines the trachea and respiratory tract as well as some male reproductive tract
Pseudostratified columnar epithelium
single layer of cells which looks like it is stratified.
Pseudostratified squamous epithelium is
only one cell layer thick, yet it appears to be stratified.Every cell touches the basement membrane.
stratified squamous
- more than one cell layer thick
- surface cells are flat
Examples of stratified squamous
- The epidermis of the skin is stratified squamous epithelium.
- The lining of the esophagus is stratified squamous epithelium.
- The cornea is covered by a non-keratinized stratified squamous epithelium.
Simple columnar epithelium
- The height of the cell is greater than the width and depth of the cell.
- one cell thick
- taller than they are wide
- oval nucleus
examples of simple columnar epithelium
Lining of the GI
Goblet cells
associated with simple columnar epithelium
Mucosa of the gall bladder
simple columnar epithelium
Simple Cuboidal Epithelium
- Tall as they are deep and wide
- cuboidal in shape
Examples of Simple Cuboidal Epithelium
- linning of ducts
- kidney tubules
Endothelium
A type of simple squamous epithelium which lines blood vessels
Mesothelium
A type of simple squamous epithelium which lines the body cavities.
Simple squamous
- a single layer thick
- cells are flat
