Classification of Epithelial tissue (Pt.2) Flashcards
(29 cards)
What are the two parts of epithelium ( like first & last name) and explain
FIRST NAME
Simple epithelia:
- single layer
Stratified epithelia:
- many layers, stacked on top of each other
LAST NAME
Cuboidal:
- boxlike, approx as tall as they are wide
Squamous:
- flattened & scale like
- nucleus is a flattened disc
Columnar:
- tall/ column shaped
- nucleus is elongated frm top to bottom, usually located closer to cell base
Where is Simple Epithelia found
- Where absorption, secretion, filtration occur & thin epithelia is desirable
Where is Stratified Epithelia found
- Common in high abrasion areas, where protection is important such as skin & lining of the mouth
How to identify Simple & Stratified Epithelia
Simple Epithelia:
- easy to classify by cell shape bc all of the cells usually have the same shape
Stratified Epithelia:
- cell shape differ in diff layers
- to avoid ambiguity, named based on shape in apical layer
Explain Simple Squamous epithelium
- Single layer of flattened cells w/ little cytoplasm
- very thin & permeable for filtration, diffusion
LOCATION of Simple Squamous Epithelium found
- Kidney glomeruli, airsacs of lungs, lining of heart, blood vessels, lymphatic vessels, serosae
Explain Simple Cuboidal Epithelium
- Single layer of cube shaped cells
FUNCTION: secretion/ absorption
LOCATION of Simple Cuboidal Epithelium
- Kidney tubules, ducts & secretory portions of small glands, ovary surface
Explain Simple Columnar Epithelium
- single layer of tall cells
FUNCTION: absorption secretion of mucus, usually w/ microvilli & goblet cells
LOCATION of Simple Columnar Epithelium
- digestive tract, gall bladder, excretory ducts, small bronchi, uterine tube , uterus
Explain Pseudostratified Columnar Epithelium
- single layer ; all cells touch basement membrane but not all are exposed to free surface. usually ciliated & w/ goblet cells
LOCATION of Psuedostratified Columnar
- trachea, upper respiratory tract, nonciliated type in male sperm carrying ducts and ducts of large glands
Explain Stratified Squamous Epithelium
- Several layers, only free surface layer is squamous- for protection against wear and tear-top layer is continually replaced
LOCATION of Stratified Squamous Epithelium
- Moist lining of esophagus, mouth, vagina, epidermis of skin (keratinized)
Explain Stratified Cuboidal Epithelium
- usually two layers of cuboidal cells, rare
LOCATION of Stratified Cuboidal Epithelium
- Mostly in ducts of some of the larger glands (Sweat glands, Mammary glands)
Explain Stratified Columnar Epithelium
- Only free surface cells are columnar, limited distribution
LOCATION of Stratified Columnar Epithelium
- pharynx, male uretha, lining some glandular ducts, transition areas or junctions btw two other types of epithelia
Explain Transitional Epithelium
- Several layers- free surface cells can change shape w/ distension of organ
LOCATION of Transitional Epithelium
- Urinary bladder
What are the special types of Epithelium
- Endothelium, Mucous membranes, Cutaneous membrane. Serous membrane
Explain Endothelium
Simple squamous- lines the cavity of all circulatory organs
LOCATION of Endothelium
- heart, blood vessels, lymphatics (reduce friction)
Explain Mucous membranes (mucosae)
- mostly stratified squamous or simple columnar epithelium- lines the cavities which open to outside
- most secrete mucous- all are absorptive and/or secretory- epithelial sheet w/ basement membrane on top of a connective tissue lamina propria (areola CT)
