epithelium and epithelial tissue (ch 4) Flashcards
what are the four basic types of tissues?
muscle, nervous, connective, epithelia,
what are the three types of epithelial tissue?
squamous, cuboidal, columnar
two types of connective tissue?
proper, specialized
three types of muscle tissue?
skeletal, cardiac, smooth
what’s included in nerve tissue?
Neurons, Neuroglia, Schwann Cells, Satellite Cells)
True or false: there is little to no extracellular matrix between epithelial cells
true
what are the three functions of the basement membrane?
Provides physical support for the epithelium
Anchors the epithelium to the connective tissue
Acts as a barrier to regulate the movement of large molecules between the epithelium and the underlying connective tissue
what binds together epithelial cells?
intercellular junctions
what are the four types of intercellular junctions?
tight, adhering, gap, desmosomes
what cells make up connective tissue?
fibroblasts and adipose (fat cells)
what three kinds of fiber make up the extracellular matrix?
collagen, elastic, reticular
what is a ground substance?
a liquid or gel containing water, complex glycosylated proteins, nutrients, and wastes
how many cell layers thick is a simple epithelium?
one layer
where are simple epithelium found?
in low-stress areas that require diffusion, filtration, secretion, or absorption (eg blood vessels)
true or false: the basal surface lies below the basement membrane
false. it’s the other way around
where are stratified epithelium found?
in areas likely to be subjected to abrasive activities or mechanical stresses (areas of wear and tear, like larynx or vagina)
why do epithelium have high regeneration rates?
cells need to be able to regenerate after injuries to skin
what is meant by epithelium being “polarized?”
epithelium are polarized in that they have a basement and an apical surface
when is the free/apical surface called a “lumen?”
when epithelium surrounds a tube or cavity
what lies BETWEEN the epithelium and connective tissue?
a basal surface, which is connected to the basement membrane
what makes up the basement membrane?
matrix of fibers (mainly collagen) and ground substance
name the two laminae of the basement membrane
basal lamina and reticular lamina
true or false: epithelia are vascular (contain blood vessels of their own)
false. epithelia are avascular
how do epithelia get nutrients and oxygen\?
from lumen or underlying connective tissue
what is ground substance?
liquid/gel containing water, glycosylated proteins, nutrients, and wastes
where is simple epithelium found?
where stress is minimal, and where absorption, secretion, diffusion, or filtration occurs (e.g. air sacs in lungs)
where is stratified epithelium found?
areas of wear and tear (e.g. skin, lining of esophagus, vagina)
what is pseudostratified epithelium?
a type of simple epithelium that appears to be stratified because some cells are short while others are tall
where can pseudostratified epithelium be found?
nasal cavity
epithelia are classified by their shape at the ____ surface
apical
what are the four types of cell shape classifications for epithelial cells?
squamous, cuboidal, columnar, transitional
why the name “transitional epithelium?”
named after ability to stretch or change shape (the apical cells are called “round” or “umbrella”)
where can transitional epithelium be found?
only in urinary passages
in what two ways are glands classified?
endocrine or exocrine
