Epithelial Tissues Flashcards
Apical Domains
These are surfaces that are in contact with a lumen, i.e. kidney tubule cells and glandular duct cells, or external environment.
Basolateral Domains
These include the 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 basal lamina.
Three (germ) layers that epithelial tissues can be derived from
Ectoderm, Endoderm, Mesoderm
Basements Membranes consists of two components
The basal Lamina, The Reticular Lamina
Basal Lamina
Next to the epithelial layer and is 50-80 nm this. It is composed of type IV collagen plus glycoproteins and is PAS+. Absent in lymph vessels and hepatic sinusoids.
Reticular Lamina
in contact with underlying connective tissue and consists of argyrophilic fibers, reticular fibers and glycoproteins.
Functions of the basement membrane
Selective filtration barrier, scaffold for embryogenesis and regeneration, stabilization of tissue shapes.
Type IV collagen
does not have fibers, it is found in the basement membranes.
Layers in Simple epithelial
One
Layers in Stratified
more than one layer
Shape of squamous cells (side View)
Flattened
Shape of cuboidal (side view)
Height approx equal to width
Shape of Columnar (side View)
height greater than width
Pseudostratified
Simple epithelium, appears to be stratified but all cells are in contact with the basal lamina. Pseudostratified may reflect stem cells (shorter cells) that are necessary to balance cell turnover by replacing more mature cells when they become aged or damaged.
Transitional epithelium
Thought to be a type of simple epithelium but having the appearance of more than one layer b/c of the positions of the nuclei. (associated with urinary track and may be referred to as urothelium)
Urothelium
Transitional epithelium
Simple squamous epithelium
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
Simple cuboidal Epithelium
In a side view, cells may be low or high. May have a brush border (kidney tubules) on apical surface compsed 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.
Simple Columnar epithelium
Intestinal cells may have striated border on apical surface composed of microvilli. * Ciliated columnar epithelium is found in the upper respiratory tract, uterine tubes, uterus, paranasal sinuses, and the central canal of the spinal cord. *non-ciliated columnar epithelium is found in the digestive tract beginning with the cardia of the stomach, the gall bladder, and in parts of the excretory ducts of glands.
Stratified squamous epithelium
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
seldom found, but may occur in small areas of the anal mucosa, large excretory ducts of some glands, and part of the male urethra.
Stratified columnar epithelium
seldom found, occurs in the ducts of adult sweat glands, fornix of the conj of the eye, parts of the male reproductive/urinary tract, the pharynx, and epiglottis.
Pseuodstratified epithelium
ciliated pseudostratified columnar epithelium is found in the trachea. *pseudostratified epithelium with stereocilia is found in the epididymis
Transitional Epithelium
Associated with urinary system *referred to as urothelium
Two Kinds of Epithelium
- Covering and Lining, 2. Glandular
Epithelial tissues function in
protection, especially stratified squamous epithelia
Epithelial tissues function to maintain concentration differences ( two examples)
- Tight Barriers 2. Leaky barriers
Epithelia involved in secretion or absorption are typically:
Simple or pseudostratified. The height of the cell often reflects the level of secretory or absorptive activity (taller=more active)
Digestive tract is most likely to be associated with:
simple non-ciliated columnar epithelium
The Vagina, esophagus, lining of the mouth, tongue and part of the epiglottis have what type of epithelial
Lightly or non-keratinized stratified squamous epithelium
Simple Squamous
Simple Cuboidal (Kidney)
Simple Columnar (Ileum)
Pseudostratified Columnar
Transitional Epithelium (ureter)
Stratified Squamous
Stratified Squamous
Stratified Squamous
Simple Cubodial (submandibular Gland)
Simple Cuboidal (submandibular Gland)
Simple Columnar (jejunum)
Simple Columnar (jejunum)
Simple Columnar (Ileum)
Simple Cuboidal (Kidney)
Simpile Cuboidal
Simple Low Cuboidal (thyroid)
Transitional Epithelium (Ureter)
Transitional Epithelium
Simple, non‐ciliated columnar epithelium is most like to be found associated with what?
digestive tract
Junctional complexes are associated with which cellular domains?
basolateral
Transitional epithelium is associated with which of the following?
urinary
The extracellular domains of which of the following bind to molecules in the extracellular matrix such as fibronectin and laminin?
integrins
Stratified cuboidal epithelium may be found where?
part of the male urethra
Lightly keratinized stratified squamous epithelium is characteristic of which location?
vaginal epithelium
Which of the following serve as a major interface between the cadherins that hold adjacent cells together and their actin cytoskeletons?
catenins
Which of the following are molecular complexes that anchor cells together and reinforce the physical integrity of tissues and the cells that make up the tissues?
zonula adherens
Which of the following are only associated with the basal domains?
hemidesmosomes
Which of the following types of cell adhesion molecules is associated with zonula occludens and desmosomes?
cadherins
The basal lamina is associated with which type of collagen?
Type IV
Desmocollins and desmogleins belong to which of the following groups of CAMs?
Cadherins
Which of the following are molecular complexes that primarily serve to prevent paracellular transport?
Zonula occludens
