1. Epithelial Tissues Flashcards
Give an example of an exterior surface that epithelial cells line.
The skin.
Give an example of an internal space that open to the exterior that epithelial cells line.
GI tract, respiratory tract or genitourinary tract.
Give an example of an internal space that does not open to the exterior that epithelial cells line.
Pericardial sac, pleural sac, peritoneum, blood vessels or lymphatic vessels.
What are the three germ layers of the embryo.
Ectoderm, mesoderm and endoderm.
What epithelium are derived from the ectoderm?
Corneal epithelium of the eye.
What epithelium are derived from the mesoderm?
Epithelia lining the blood vessels, lymphatic vessels, pericardial sac, pleural sac and peritoneal.
What epithelium are derived from the endoderm?
Epithelia of the respiratory tract, GI tract, liver and many glands (thyroid, thymus and salivary).
What is the difference between simple and stratified epithelia?
Simple epithelia have one layer of cells but stratified epithelia have multiple layers of cells.
What is the basement membrane?
The thin flexible, acellular layer that lies between epithelial cells and the subtending connective tissue consisting of a basal lamina that lies next to the epithelial cells.
What are the purposes of the basement membrane?
A strong, flexible layer that epithelial cells adhere to, acts as a cellular and molecular filter.
What is the appearance of the simple squamous epithelia?
Flat cells with central nuclei.
Where can simple squamous epithelia be found?
The parietal layer of the Bowman’s capsule, the lining of arterioles, the lining of body cavities, the lining of lymphatics.
What are the functions of simple squamous epithelia?
Lubrication, gas exchange, barrier and active transport.
What is the appearance of simple cuboidal epithelia?
Cubes.
Where can cuboidal epithelia be found?
Thyroid follicles, small ducts of exocrine glands, kidney tubules and surface of ovary.
What are the functions of simple cuboidal epithelia?
Absorption, conduit, secretion, barrier/ covering, hormone synthesis, storage and mobilisation.
What is the appearance of simple columnar epithelia?
Cells that are taller than they are wide, columns.
Where can simple columnar epithelia be found?
Lining the crypts of Leiberkühn (intestinal gland), the gall bladder, the salivary gland and lining the Fallopian tube of the uterus.
What are the functions of simple columnar epithelia?
Absorb water, removal of sodium ions in saliva and transport.
What is the appearance of simple columnar with microvilli?
Taller than they are wide, columns, with thousands of microvilli on their surface.
Where can simple columnar with microvilli epithelia be found?
Stomach lining and gastric glands, small intestine and colon.
What are the functions of simple columnar with microvilli epithelia?
Absorption, secretion and lubrication.
What is the appearance of pseudostratified epithelia?
There appears to be several layers of epithelia cells, with not all touching the basement membrane. But actually there is only one layer and all cells touch the basement membrane.
Where can pseudostratified epithelia be found?
Upper respiratory tract: nasal cavity; trachea; bronchi, epididymis, ductus deferents, auditory tube, lacrimal sac, large excretory ducts.
