Epithelial Tissue (Exam 1) Flashcards
What s the most cellular tissue in the body
Epithelial tissue
how are epithelial tissues named
according to arrangement of cells (aka layers (simple, stratified) according to type ( squamous, cuboidal, columnar, Special types (pseudo stratified and transitional (urothelium))
what is epithelioid tissues
Resemble epithelial tissue but lack free surface
- often used to describe tumors
all epithelial cells display what
typically display Free surfaces, polarity, do not contain blood vessels, uniform geometric shape when viewed form the side, cells are tightly bound together, relatively little intercellular matrix
Apical domains
Surfaces of the cells that are in contact with a lumen
Basolateral domains
surfaces of cells that are locked together by special junctional complexes with neighboring cells as well as the surface opposite the apical domain that is in contact with the basil lamina
Epithelial tissues may be derived from what embryonic layer (s)
Ectoderm (the skin epidermis and glands)
Endoderm (the lining of the GI tract (including glands)
Mesoderm (The lining of blood vessels, mesothelium, and bowman’s capsule
Epithelial tissues sit on top of what
The basement membrane
The basement membrane consists of what two components
Basal lamina and Reticular lamina
How thick is the basal lamina
50-80 nm thick
what is the basal lamina composed of
Type IV collagen puls glycoproteins
is PAS+ .
where is the basal lamina absent
Lymph vessels and hepatic sinusoids
What is the reticular lamina in contact with
The bottom part of the basement membrane and is in contact with the underlying CT
what is the reticular lamina composed of
argyrophilic fibers, reticular fibers and glycoproteins
what are the functions of the basement membrane
Selective filtration barrier
scaffold for embryogenesis and regeneration
stabilization of tissue shapes
can epithelial tissues be innervated
yes
Do epithelial tissues form secretory and excretory parts of glands
yes
Do epithelial tissues line body cavities and cover body surfaces
Yes
Lightly Keratinized epithelium may be found where
esophagus and vagina
Heavily keratinized epithelium may be found where
epidermis
Is psuedostratified a type of simple or stratified type of epithelium
Simple
The pseudo stratified arrangement may be explain by what
some epithelia may reflect the role of stem cells (the sorter cells in the layer) that are necessary to balance cell turnover by replacing more mature cells when they become aged or damaged
Transitional epithelium is thought to be simple or stratified
simple but with the appearance of having more than one layer because of the positions of the nuclei
The apical domains are characterized by surface modifications such as
Cilia or microvilli
the apical domains face what
The lumen or external environment
The basolateral domains are characterized by what
intercellular junctions
where is simple squamous epithelium found
Lines lumina of ducts, vessels, and other tubular structures
forms walls of alveoli, bowman’s capsules and inner surfaces of membranous labyrinth and tympanic membrane
Where is simple cuboidal epithelium found
surface of ovary, pigmented epithelium of retina, kidney tubules, glands and ducts, terminal bronchioles, choroid plexus, and anterior capsule of lens of eye
Simple ciliated columnar epithelium may be found where
upper respiratory tract, uterine tubes, uterus, paranasal sinuses, and the central canal of the spinal cord.
simple non-ciliated epithelium is found where
in the digestive tract beginning with the cardia of the stomach, the gall bladder, and in parts of the excretory ducts of glands
Where is heavily stratified squamous with CT papillae found
Epidermis
where is heavily stratified squamous epithelium without CT papillae found
The cornea
Where is lightly or non-keratinized stratified squamous epithelium found
Esophagus, vagina, lining of the mouth, tongue, and part of the epiglottis
Where is stratified cuboidal epithelium found
may occur in small areas of the anal mucosa, large excretory ducts of some glands, and part of the male urethra
Where is stratified columnar epithelium found
ducts of adult sweat glands, fornix of the conjunctiva of the eye, parts of the male reproductive/urinary tract, the pharynx, and the epiglottis
where is ciliated psuedostratified columnar epithelium is found where
Trachea
where is psuedostratified epithelium with stereocilia found
in the epididymis
Where is transitional epithelium found
Urinary system
what are the two kinds of epithelium in terms of function
Covering/lining and glandular
functions of epithelium
protection, maintain concentration differences, involved in secretion and absorption
What epithelia are typically involved in secretion and absorption
simple columnar primarily functions in secretion of enzymes and mucous and absorption of nutrients and fluid
