LAB - Epithelium & Glands Flashcards
Epithelial tissues share common characteristics:
- line all boy surfaces, cavities, and tubes
- cells with little intercellular substance
- cells hape shape
- cells form cohesive layer; attach to each other through specializations of their plasma membranes (lateral specialization)
- cells may have surface specialization = cilia, microvilli, stereocilia, or keratin
- rest on BM
- no direct blood supply; nutrients diffuse through BM
epithelial tissues classified according to…
three morphological characteristics:
- how many layers are present?
- what shape are the cells?
- is there surace specialization?
glandular epithelium may be classified according to these criteria: (3)
- presence or absence of ducts
- how the secretory product is released from the cell
> exocrine gland can be subclassified : do ducts branch? simple = no; compound = yes - what shape is the secretory unit?
the unusual secretory unit of thyroid gland
- endocrine
- called a follicle
when simple squamous epithelium allows fluid to enter and exit cavities in the peritoneal cavity
mesothelium
simple cuboidal epithelium usually lines…
small ducts and tubules; excretory, absorptive, and secretory
simple columnar epithelium is most often found on …
highly absorptive surfaces (small intestine) and on secreotry surfaces (stomach)
This epithelium is not common in humans except in the female reproductive tract
simple columnar ciliated = fallopian tube
this is almost exclusively found in airways of the respiratory system in mammals
pseudostratified epithelium = “respiratory epithelium”
in stratified epithelium, as cells migrate to the surface, their nucleus becomes exceedingly
pyknotic and they eventually disintegrate
this epithelium is usually found in the larger ducts of exocrine glands
stratified cuboidal; usually two or three layers thick
