Epithelial Tissue Flashcards
What is embryonic origin from mostly ectoderm and endoderm.
Epithelial Tissue
What are some common features of epithelial tissues?
- Avascular
- High capacity for repair
- Always on a connective tissue bed
- Very little or no intercellular substance-closely packed cells.
- Always rests on the basement membrane in between the connective tissue.
What are the types of epithelial tissues based on cell shape?
- Squamous: width of the cell is greater than its height.
- Cuboidal: the width, depth, and height are approximately the same
- Columnar: the height of the cell exceeds its width
What are types of epithelia tissues based on surface additions ?
& cell arrangement ?
- keratin
- cilia
- Microvilli
- simple: when the tissues is one layer thick
- stratified: when the tissues is more than one layer thick
What is simple squamous, cuboidal, and columnar?
- squamous: can be ciliated and is found in capillaries, alveoli of the lungs, Bowman’s capsule of the kidneys.
- cuboidal: non ciliated, found in tubules and ducts.
- columnar: ciliated/non-ciliated, found in digestive tract, gall bladder, and uterine tube.
What is psuedostratified?
the cells appear to be stratified although some cells do not reach the surface.
ciliated/non ciliated: found in the upper respiratory tract, male urethra, and trachea.
What is psuedostratified?
the cells appear to be stratified although some cells do not reach the surface.
ciliated/non ciliated: found in the upper respiratory tract, male urethra, and trachea.
What is stratified squamous, cuboidal, and columnar?
- squamous: most common, keratinized/non keratinized: found in cornea, epidermis, esophagus, and oral cavity.
- cuboidal: sweat glands, large ducts of the exocrine glands.
- columnar: rare, olfactory mucosa, largest ducts of exocrine gland.
What is stratified squamous, cuboidal, and columnar?
- squamous: most common, keratinized/non keratinized: found in cornea, epidermis, esophagus, and oral cavity.
- cuboidal: sweat glands, large ducts of the exocrine glands.
- columnar: rare, olfactory mucosa, largest ducts of exocrine gland.
What is a membrane?
defined as surface epithelium along with its always present underlying connective tissue
What are the two types of membranes?
Mucous membranes: lines the cavities that connect with the outside of the body. (alimentary canal, respiratory tract, and genitourinary tract)
Serous membrane: lines the peritoneal, pericardial, and pleural cavities.
What are the specific names given to epithelium in certain locations?
- Epithelium: covering internal and external surfaces of the body.
- Mesothelium: lining body cavities especially the heart
- Endothelium: lining the lumen of blood and lymphatic vessels.
Where does mesothelium and endothelium come from ? & what does it develop from
Mesothelium and Endothelium come from the mesodermal layer and develops from undifferentiated mesencymal cells.
Where does mesothelium and endothelium come from ? & what does it develop from
Mesothelium and Endothelium come from the mesodermal layer and develops from undifferentiated mesencymal cells.
What is Glandular Epithelium?
Exocrine glands: secrete their products onto a surface directly or through epithelial ducts or tubules that are connected to a surface. Classified as: unicellular (secretory component consists of a single type of cell) multicellular: (composed of more than one secretory cell type) which is further classified as :
simple: the duct is unbranched
compound: the duct is branched
tubular: secretory portion is shaped like a tube.
acinar: secretory portion is shaped like a flask.
Endocrine grands: lack a duct system and secrete directly into tissue from which it enters the blood steam and reaches target cells.
Secretions are called hormones.
