Lecture 1 - Epithelial Tissue Flashcards
Epithelial cells have relatively little _________? and contain no _________?
Intercellular Matrix/substance
NO Blood vessels
Epithelial cells may be derived from which of the 3 germ layers?
ALL 3 endo, meso, ecto
Epithelial tissue derived from the Ectoderm forms which tissues?
Tissues of the Epidermis and Glands
Epithelial tissue derived from the Endoderm forms which tissues?
Tissues of the Digestive Tract, including Glands
Epithelial tissue derived from the Mesoderm forms which tissues?
Tissue lining of blood vessels, mesothelium, Bowman’s capsule
Epithelial tissues sit on top of what? which consists of what 2 components?
Basal Membrane, which consists of Basal Lamina and Reticular Lamina
5 FACTS to describe the basal lamina
next to the epithelial layer
50-80 nm thick
composed of type IV collagen plus glycoproteins
PAS+
absent in lymph vessels and hepatic sinusoids.
Epithelia line and cover all body surfaces except what 3 things
the articular cartilage, the enamel of the tooth, and the anterior surface of the iris.
The basic 7 functions of epithelia are:
protection (skin), absorption (small and large intestine), transport of material at the surface (mediated by cilia), secretion (glands), excretion (tubules of the kidneys), gas exchange (lung alveolus), and gliding between surfaces (mesothelium).
reticular lamina is located in? and consists of what 3 things? and performs what function?
is in contact with underlying connective tissue. under the basial lamina and part of the basment membrane.
Consists of argyrophilic fibers, reticular fibers and
glycoproteins.
Anchors Basal Lamine to the Connective Tissue.
3 Functions of the basement membrane:
- Selective filtration barrier
- Scaffold for embryogenesis and regeneration
- Stabilization of tissue shapes
Are Epithelial Tissues Innervated?
yes, they may be. but not always.
What tissues are lightly keratinized
Tissues of Esophagus and vagina
simple cuboidal cells are most commonly assocatied with which tissues?
kidney, renal tubules
the appearance of stratification in pseudostratified columnar epithelium AND transitional epithelium cells is due to?
The nuclei being located at different distances from basal lamina. but in reality all cells touch the basal memb. and therefore the cells are simple.
Transitional epithelium is simple or columnar? and is associate with which what part of the body?
Simple.
The urinary track and may be referred to as urothelium.
What other unique quality of transitional epithelial cells should be looked for to identify?
They contain dome shaped plaques on their apical surfaces
Cilia consist of Assemblies called ________? Which are formed by a _____arrangement? and are connected to a ______ within the _______? which is connected to the cell by ______?
Axonemes 9+2 microtubules doublet Basal Body cytoplasm rootlets
Due to the Axonemes arrangement of a cillium, What other structure is most similar to a cillium.
the tail of a sperm or Flagellum.
What is unique about the basement membrane, when compared to the Epithelial CELLS connected to it?
The basement membrane is NON cellular
Is it the basic function of Epithelial tissues to form a tight barrier to prevent concentration changes?
No, its not a basic function, though it can be a specific function B/C their basic function is to MAINTAIN CONCENTRATION DIFFERENCES, which means, some will be leaky and others tight, depending on the specific needs of the tissue.
Simple squamous epithelium forms? and is located?
- Forms walls of alveoli, Bowman’s capsules and inner surfaces of membranous labyrinth and tympanic membrane of the ear
- Lines lumina of ducts, vessels, and other tubular structures
Whats unique about the side view of Simple cuboidal epithelium?
• In side view, cells may be low or high (approaching almost squamous or almost columnar).
Simple cuboidal cells may have what type of border? and is found on/in?
• May have a brush border (kidney tubules) on apical surface composed of
microvilli
• Found on surface of ovary, pigmented epithelium of retina, kidney tubules,
glands and ducts, terminal bronchioles, choroid plexus, and anterior
capsule of lens of eye.
Does the apical surface of Simple columnar epithelium typically contain, microvilli, cilia, or neither?
All 3, depending on the location.
•Microvilli - intestines,(give striated appearance)
AKA: brush border
•Cilia - upper respiratory tract,
uterine tubes, uterus, paranasal sinuses, and the central canal of the spinal cord.
•Non ciliated - digestive tract beginning
with the cardia of the stomach, the gall bladder, and in parts of the excretory ducts of glands.
Stratified squamous epithelium types?
Heavily keratinized or
Lightly or non- keratinized
Heavily keratinized stratified squamous epithelium is found in the
epidermis with connective tissue papillae and in the cornea without connective tissue papillae.
Lightly or non- keratinized stratified squamous epithelium is found in the
esophagus, vagina, lining of the mouth, tongue, and part of the epiglottis.
Stratified cuboidal epithelium is found?
• Seldom found, but may occur in small areas of the
anal mucosa,
large excretory ducts of some glands,
male urethra.
Stratified columnar epithelium is found?
• Seldom found; occurs in the ducts of adult sweat glands, fornix of theconjunctiva of the eye, male reproductive/urinary tract, pharynx, epiglottis.
Pseudostratified epithelium has what 2 types and where are both found?
- Ciliated - trachea.
* stereocilia - epididymis.
Stereocilia are similar to ?
microvilli but are longer and are often
branched.
2 places in body that require the epithelial tissues to have Leaky barriers?
- Lining of gallbladder
* Proximal convoluted portion of renal tubule
