Histology Lecture 3: Characteristics and classification of epithelial tissues Flashcards
T or F: Epithelial tissue is the most cellular tissue in the body
True
Epithelial tissue classifications (they are classified according to what?)
Shape and # of layers
T or F: Epithelial tissues have large intercellular matrix
False
T or F: Epithelial tissues typically display free surfaces
True
T or F: Epithelial tissues line body cavities and cover body surfaces
True
Epithelial tissues form which parts of glands
Secretory and Excretory parts
Are epithelial tissues innervated
They may be
Apical domain
surface of cell in contact with a lumen or external environment
Basolateral domain
Surface of cell in contact with neighboring cells or the basal lamina
T or F: Epithelial tissues contain blood vessels
False
Epithelial tissues are derived from what
Ectoderm
Endoderm
Mesoderm
Surface modifications of epithelial tissues
Cilia
Microvilli (brush border)
Stereocilia (longer and branched compared to microvilli)
Epithelial tissues are classified by
shape
cell layers
surface modifications
Presence or absence of keratin
What is pseudostratified epithelium
Simple epithelium, appears stratified because of nuclei locations but all cells are in contact with basal lamina
What is transitional (urothelium) epithelium
Simple epithelium, dome shaped surface and nuclei location gives appearance of stratified. Found in urinary tract
Simple squamous locations
Lumina of ducts, vessels and other tubular structures.
Walls of alveoli, bowmans capsules and inner surfaces of labrynth and TM
Simple cuboidal location and apical modification
May have brush border
Found on surface of ovary, pigmented epithelium of retina, kidney tubules, glands and ducts, terminal bronchioles, choroid plexus, anterior capsule of lens of eye
Simple columnar apical modifications
Microvilli, cilia
Location of simple columnar w/ microvilli
Intestinal cells
Location of simple columnar w/ cilia
Upper respiratory tract, uterine tubes, uterus, sinuses, central canal of spinal cord
Location of simple columnar w/o cilia
digestive tract beginning with cardia of stomach, gall bladder, excretory ducts
Heavily keratinized stratified squamous location
epidermis w/CT papillae
cornea w/o CT papillae
Light or non keratinized stratified squamous location
esophagus, vagina, mouth lining, tongue, epiglottis
Stratified cuboidal location
seldom found but:
anal mucosa
large excretory ducts of some glands
parts of male urethra
stratified columnar location
seldom found but:
ducts of adult sweat glands
pharynx
epiglottis
Pseudostratified w/cilia location
trachea
Pseudostratified w/stereocilia location
epididymis
Two function types of epithelium
Covering and lining
Glandular
Main functions of epithelium
Protection (especially stratified squamous)
Maintaining cell concentration differences
Types of epithelia involved in secretion or absorption
Simple or pseudostratified
simple columnar functions primarily in what
secretion of enzymes and mucous, absorption of nutrients and fluids
microvilli structure
Actin filament core, cross linked by villin and fimbrin, distal end capped by formin. Core extends into terminal web.
microvilli (brush border) function
increase surface area of absorption
Microvilli location (think what function is)
intestinal epithelium & parts of renal tubules
structure of cilium
9 peripheral doublets + 2 central pair of microtubules
alpha tubule structure
13 protofilamints, pairs of dynein arms projecting to beta tubule
Beta tubule structure
10-11 protofilaments
