Anatomy of Epithelia Flashcards
What are the main ways in identifying epithilium?
Number of layers
Simple (one layer)
Stratified (multiple layers)
Cell morphology
Squamous (flat)
cuboidal (circular)
columnar (columns / simple)
Describe Simple Squamous
Very thin and small
Locations: Vascular system Body Cavities Bowman's Capsule Lung Alveoli
Describe Simple Cuboidal
Circular orientation
Locations: Small ducts of exocrine glands Surface of ovary Kidney tubules Thyroid follicles
Describe Simple Columnar
Ciliated and non ciliated
Appear with dark nuclei right next to each other
Locations:
Small intestine and colon
Stomach lining and gastric glands
Gallbladder
Describe Pseudostratified columnar
Ciliated - cilia
Non-ciliated - microvillia/sterocilia
Look like simple columnar except nuclei are at slightly different levels of height
Locations:
Trachea and bronchial tree
Ductus deferns
Efferent fuctules
Describe Stratified Squamous
Barrier & Protection
Keratinized:
Have thin cells at top without nuclei
Non-keratinized
Nucleated superficial squamous cells
Rests on basal lamina
Locations:
Epidermis
Oral cavity and esophagus
Vagina
Describe Stratified Cuboidal
Barrier & Conduit (water related)
Layers of cuboidal cells (circular shaped and layered)
Locations:
Sweat glands
Large ducts of exocrine glands
Anorectal junction
Describe Stratified Columnar
Barrier & Conduit (water related)
Largest ducts of exocrine glands
Locations:
Largest ducts of exocrine glands
Anorectal Junction
Describe Transitional stratified epithelium
Barrier & detensible
Looks like stratified columnar except have umbrella cells (rounded ends) at the top
Locations: Renal calyces Ureters Bladder Urethra
Describe polarity of epithelial cells?
Side facing a space/lumen is APICAL pole
Opposite end in contact with ECM and connective tissue is BASAL pole
Describe microvilli
Apical Domain
Look like a brush
Increase surface area for absorption and visible in LM
Describe stereocilia
Apical Domain
long microvilli
Male reproduction and inner ear (sensory mechanoreceptors)
Describe Motile Cilia
Apical Domain
Hair like extensions of apical plasma membrane
Describe types of exocrine glands and their appearance
Unicellular - goblet cells
Multicellular - branched and simple
