Epithelial tissue Flashcards
Characteristics
Cell junction
Polarity
Attachment
Avascularity
Regeneration
Function
Physical protection
Control permeability
Sensation
Secretion
WHat increases surface area
Microvilli increase absorption/secreation
Cilia moves fluids
what holds it together
intercellular connections
attachment to basement membrane
maintenance and repair
Intercellular connections
cell junctions
bonds between adjacent cells
support and communication
tight junction
nothing goes through
Whar does intercellular connections include
tight junction
gap junction
desmosomes
gap junction
things go through for communication
desmosome
belt (continious hold around)
button (interupted hold around)
Basement Membrane
Basal Lamina
2 layers
what are the 2 layers of basement membrane
lamina lucida
lamina densa
lamina lucida
thin layer produced by epithelium
Lamina densa
thick fibers produced by connective tissues
Hemidesmosomes
Attachment of epithelial cells to basal lamina
What is the maintenance and repair of epithelial cells
replaced by division of STEM cells
What are the classifications of epithelial tissues
Epithelia
Glands
Epithelia
surface epithelium (skin)
layers of cells covering external or lining internal surface
glands
structures that produce secretion
WHat are the classifications of surface epithelia (shape)
squamous
cuboidal
columnar
WHat are the classifications for surface epithelia (# of layers)
simple
stratified
Simple squamous epithelium
reduces friction
lung alveoli
stratified squamous epithelium
physical protections
skin
simple cuboidal epithelium
absorption and secretion
renal tubule
Stratified cuboidal epithelium
protection, absorption and secretion
sweat/mammary glands
Transitional cuboidal epithelium
can stretch and glide
stretch and recoil
urinary bladder
Simple columnar epithelium
absorption and secretion
stomach, intestine
-microvilli for surface area + absorption
Stratified columnar epithelium
protection
salivary gland duct
Pseudostratified columnar epithelium
protection, secretion, cilia movement
trachea, bronchi
diff cell heigh = looks like layer
pseudo = fake
really only 1 layer
Glandular epithelium
endocrine glands
exocrine glands
endocrine glands
no duct
release hormones to interstitial fluid ie blood
thyroid/adrenal gland
exocrine gland
produce secretion
have duct to epithelial surface
sweat gland
types of exocrine secretion
merocrine
apocrine
holocrine
Merocrine
released by vesicle
exocytosis
sweat gland
apocrine
released by shedding cytoplasm
cell stays alive and repeats
eg milk from mammary gland
Holocrine
released by cells bursting
cells die
replaced by stem cells
sebaceous gland
structure of exocrine cells
unicellular
multicellular
unicellular exocrine cell
goblet (only type)
scattered along epithelia
intestinal line
secrete mucin = makes mucous
Multicellular exocrine cell structure of duct
simple (undivided)
compound (divided)
Multicellular exocrine cell shape of secretion portion
tubular (tube)
alveolar/acinar (chamber)
tubuloaveolar (mix of both)
