Epithelium Flashcards
basal lamina
supporting sheet between the epithelium and the connective tissue
consists of proteins secreted by epithelial cells
acts as a selective filter, scaffolding
basement membrane
basal lamina + layer of reticular fibers belonging to the underlying connective tissue
microvilli
fingerlike extensions of the plasma membrane of apical epithelial cells
core of actin filaments
maximize surface area for absorption
help anchor mucus sheets to epithelial surface
cilia
whiplike
highly motile
core of microtubules held together by cross linking and radical proteins
arranged in pairs (doublets) with 9 outer doublets encircling one central pair
move with help of each other and the motor protein dynein
move substances along epithelial surface
simple squamous epithelium (function, location)
absorption
lines blood vessels, air sacs of lung
simple columnar epithelium, with microvilli (function, location)
absorption
lines small intestine
stratified squamous epithelium (function, location)
protective layer
skin, lining of mouth, esophagus
pseudostratified, ciliated columnar epithelium (function, location)
movement of substances along air passageway
lines nasal cavity and trachea
transitional epithelium (function, location)
allows for distension/stretching of the bladder
bladder
exocrine gland
external secretion into body cavities or onto body surfaces
endocrine gland
internal secretion; secrete directly into tissue fluid that surrounds them
goblet cell (definition, locations, function)
type of unicellular exocrine gland epithelial lining of intestines, respiratory tubes, between columnar cells with other functions produce mucin (glycoprotein, dissolves in water); mucin + water = mucus (covers, protects, lubricates many internal body surfaces
