epithelial tissues Flashcards
functions of epithelial tissue? (6)
protection, control permeability, absorption, secretion, provide sensation
what are the characteristics of epithelial tissue?
cells held tightly together=form barriers, special junctions:
tight junction, desmosomes, and gap junctions
cells have?
polarity
what does the basal surface sit on?
basement membrane composed of basal lamina (glycoprotein layer secreted by epithelial cells)
function and location of simple squamous?
reduces distance and time required for diffusion: lining of lungs, alveoli capillaries, smooth lining for heart, blood vessels
function and location of simple cuboidal?
secretes/absorbs in ducts and tubes: kidney tubules, pancreatic duct, thyroid gland, salivary gland
function and location of simple columnar ?
secretes/absorbs in tubes and across large surfaces: stomach intestines
function and location of stratified squamous?
protect against abrasion, chemicals, pathogens: skin, lining of throat, esophagus, rectum, anus, vagina
function and location of stratified cuboidal?
protects and secretes: ducts of sweat glands and mammary gland
function and location of pseudo stratified columnar?
protects, secretes, moves material along passageway: lines nasal cavity, trachea, bronchi, bronchioles
function and location of transitional
protects while stretching and recoiling: lines bladder and uterus
what are the two types of glands epithelial tissue form?
exocrine and endocrine
what do goblet cells secrete
mucin
what two parts do exocrine glands consist of?
secretary unit (tubular or alveolar) and duct (simple or compound)
what are the 3 types of exocrine glands?
merocrine, holocrine and apocrine
function and location of merocrine gland?
most exocrine gland, secrete products from vesicles by exocytosis
ex. pancreas, salivary gland, sweat, goblet
function and location of holocrine gland?
secretion accumulates and whole cell bursts releasing secretion
ex. sebaceous gland
function and location of apocrine gland?
secretory product accumulates at apex of cell and apex breaks off
ex. mammary glands
what are the function of endocrine glands?
secrete hormones, most formed from epithelial tissue, ductless
ex. thyroid, adrenal, ovary, testes