Epithelium Flashcards
Two major types of epithelium
SURFACE: line internal surfaces and cover external surfaces.
GLANDULAR: form all glands in the body.
Types of surface epithelial tissues.
Classified according to shape of cell and number of cell layers formed.
SQUAMOUS: flattened and thin.
CUBOIDAL: boxy, as wide as it is tall.
COLUMNAR: rectangular, taller than it is wide.
SIMPLE: one layer of cells.
STRATIFIED: more than one.
PSEUDOSTRATIFIED: single layer of irregularly shaped cells (pseudostratified columnar).
General features of epithelial tissues
Closely opposing cells.
Very little intracellular material.
Avascular (don’t have blood vessels).
What type of epithelia is this?
Where is it located?
What is it’s function?
Transitional epithelium.
Lines bladder and urethra.
Allows urinary organs to expand and stretch.
What type of epithelia is this?
Where is it located?
What is it’s function?
Stratified columnar epithelium.
Male urethra.
Secretes and protects.
What type of epithelia is this?
Where is it located?
What is it’s function?
Stratified cuboidal epithelium.
Sweat, salivary and mammary glands.
Protective tissue.
What type of epithelia is this?
Where is it located?
What is it’s function?
Stratified squamous epithelium.
Lines oesophagus, mouth and vagina.
Protects against abrasion.
What type of epithelia is this?
Where is it located?
What is it’s function?
Pseudo-stratified columnar epithelium.
Lines the trachea and upper respiratory tract.
Secretes mucus.
What type of epithelia is this?
Where is it located?
What is it’s function?
Simple columnar epithelium.
Ciliated tissues are in bronchi, uterine tubes, and uterus. Non ciliated are in the digestive tract and bladder.
Absorbs. Also secretes mucus and enzymes.
What type of epithelia is this?
Where is it located?
What is it’s function?
Simple squamous epithelium.
Air sacs of lungs and lining of the heart, blood vessels and lymphatic vessels.
Allow materials to pass through, and secretes lubricating substance.
Keratinised vs non keratinised??
What is an exocrine gland?
Passes it’s secretion into a duct which in turn carries it to a body surface.
What is an endocrine gland?
Has no ducts and passes it’s secretion directly into blood capillaries and/or lymphatic capillaries.
Examples of endocrine glands.
Hypothalamus, pituitary, thyroid.
Examples of exocrine glands.
Sweat, salivary, mammary glands.
