The Epithelium tissue Flashcards
What are the five characteristics of epithelial tissue?
1.)Polarity: cells have apical surface facing the body & basal surface that attaches to basement membrane
2.)Cellularity: cells are tightly packed with minimal cellular matrix
3.)Vascularization: tissue lacks its own blood supply and retains nutrients from underlying tissue
4.)High regenerative capacity.
5.)The tissue is anchored to the connective tissue.
Describe the texture of apical surfaces?
Smooth and slick.
True or False: Epithelium is classified by arrangement of cells.
True
What forms endocrine and exocrine glands?
The epithelium
What is in the extracellular matrix and consists of cells?
The connective tissue.
What tissues are derived from the mesenchyme?
The epithelium, muscle, and connective tissue.
What is the microvilli and what function does it serve? Where is it located?
The microvilli are located on the apical surface of the epithelium. They expand surface area for nutrient absorption in the gi tract.
What is the basal surface?
The epithelial surface attached to underlying connective tissue.
What is the basal lamina?
The molecule filtration system which diffuses materials passing through to underlying connective tissues. It is also the scaffolding by which cells migrate through for wound repair.
What is found within the basal lamina?
Glycoprotein secretions and collagen fibers.
Describe epithelial “special contacts”.
Continuous sheets of closely aligned cells which prevent the leakage of substances through spaces between cells. These prevent adhesive proteins from pulling apart.
What is the basement membrane? What is its function?
The basement membrane is the two layers of cells between the epithelia and connective tissue which reinforces the epithelial sheet by resisting tears or stretching.
Where is the basement membrane located?
It defines the epithelial boundary located in between the epithelium and the connective tissue.
What is the basement membrane comprised of?
Two layers:
The basal and reticular lamina. These are layers of extracellular material which contain collagen and protein fiber which lead to the underlying connective tissue.
True or False: The epithelium lacks blood vessels.
True is avascular.
