Lecture 2: Epithelium Flashcards
What is epithelium and its four functions?
A basic tissue type.
- Absopative
- Secretory
- Excetory
- Protective
What are the three embryological layers of epithelium?
- Ectoderm
- Mesoderm
- Endoderm
Where is ectoderm epithelium found?
Forms the skin. Oral, nasal and anal passages.
Where is mesoderm epithelium found?
Lines the cardiovascular system. Lines the thoracic and adbominal cavities. Ducts and accessory glands of the urogential system.
Where is endoderm epithelium found?
Gut, respiratory tract, urinary bladder, liver, gall bladder and the pancreas.
What are the three types of cell proliferation?
- Permanent - cell division does not occur in adult life
- Stable - can only replicate under certain conditions
- Labile - renewable
What are the three polarities of epithelium?
- Apical - faces the lumen (top)
- Basal - faces extracellular matrix (bottom)
- Lateral - adherent to adjacent cells
What type of epithelial cells are avascular?
Epithelial sheets
How do epithelial cells gain oxygen and nutrients?
Through diffusion only/
What type of epithelium are vascular as they need blood supply?
Glandular epithelia
What component is responsible for cell to cell adhesion?
Desmosome
What is the function of the basement membrane?
Separates epithelial cells from underlying supportive structures.
What is the function of goblet cells?
The secretion of mucous
What is a function of epithelium seen in sweat glands?
Excretion
What function of epithelium associates with gas exchange and nutrient absorption?
Interchange with the environment.
