Histology Week 2 - Epithelium and Epithelial Glands Flashcards
Describe the characteristic features that distinguish epithelium from other tissues. *Classify the types of epithelia and give examples of their location
Epithelium cells are closesly packed strong cells forming cellular sheets. These cells are avascular, face a lumen, rest atop connective tissue, produce a basal laminal, and show polarity. There are a few classifications of epithelia: simple epithelium (one-layer), stratified epithelium (multiple layers). Simple squamous epithelium is locaated on the lining of vessels, cuboidal epithelium on the ovary and thyroid, pseudostratified columnar epithelium on the trachea, bronchi, and nasal cavity, stratified epithelium on the epidermis, esophagus, cornea, transitional epithelium on the bladder, ureters, and columnar epithelium on the intestines and gallbladder. These are some of the many examples of the epithelium.
Classify the exocrine glands on the basis of structural criteria
See images*
Explain the composition of the basement
membrane and detail its characteristics
at the light microscopy and electron microscope level
Composition is a majority of the Laminin - See images
Understand the different methods of secretion of exocrine glands
There are two exocrine gland secretion methods: Holocrine where the whole cell disintegrates (sebaceous gland) and Apocrine where part of the cell is released (mammary gland).
Identify the types of junctions found
between epithelial cells and their protein
composition
Zonula occludens, zonula adherens, dermasomes, gap junctions, and hemidesmosomes.
List the apical surface modifications
found in epithelial cells and consider their function.
There are the microvilli, which increase the surface area for absorption, stereocilia which increase surface area for absorption and are also present in absorptive tissue, and cilia which functions the movement of substances over the cell surface.
