L8: Epithelial tissue Flashcards
Epithelium plays an important role in
Diffusion
Absorption
Secretion
Tissue is:
- A diverse group of cells
- With an ordered structure
- Working together for a common function
4 types of tissue:
- Epithelial
- Connective
- Muscle
- Nervous
The basic characteristic of epithelial tissue:
- Covers body surface, lines body cavities
- form glands (skin, airways, digestive lining, and urinary tract lining)
- Closely packed cells
- little extracellular materials
- Basement membrane
- Avascular
- Highly regenerative (using stem cells) (high mitotic activity)
cells in epithelial tissue are joined by….
by Specialized cell-to-cell junctions
describe the Basement membrane:
- It’s a non-cellular membrane
- Compromised of polysaccharide-rich membrane
The function of basement membrane:
- Separates epithelium from underlying connective tissue
- Acts as a sieve to prevent materials from entering the body
The key characteristic of epithelial tissue?
Avascular
why is the epithelial cell highly regenerative
Cells completely lack bloody supply (that’s why they’re highly regenerative)
which is side is the Free surface
- Is the apical side
- Bound to the basolateral side
The function of epithelial tissue:
- Secretion
- Selective absorption
- Protection
- Transcellular transport
- Detection of sensation
Examples of secretion:
- Digestive tract
- Involved in high secretion activity
Selective absorption:
- First contact with the material
- And allows them to be absorbed
selective absorption is associated with a structure known as
microvilli (inc surface area)
the function of Transcellular transport:
- aid the movement of substances from cell-to-cell through a certain distance
- Ex: mucus
What structure does transcellular transport:
cilia
Detection of sensation:
- 1st layer with the outer environment
- To detect sensation along with nerve cells