Module 4: Epithelial Tissue Flashcards
What are the 2 types of Epithelial Tissue?
- Covering/Lining Epithelium
- Glandular Epithelium
Covering/Lining Epithelium:
Forms outer layer of skin and
internal structures
Glandular Epithelium
Forms glands of body
6 Functions of Epithelia:
- Protection
- Absorption
- Filtration
- Excretion
- Secretion
- Sensory reception
Apical Surface
- Free surface exposed to exterior environment or cavity
of organ (essentially just the top surface of skin) - Often have microvilli or cilia
Basal Surface
Inside/bottom layer than anchors the skin
Basal Lamina
- Adhesive sheet beneath Basal Surface
- Joins epithelial
tissue to connective tissue
Fun Facts about Epithelial Tissue!
- Avascular, but are innervated
- High regenerative capacity…paper cut heals fast
CLASSIFICATION: Simple
- One layer of cells
↓ Therefore, it’s a thin sheet
↓ Good for diffusion - Absorption, Secretion, Filtration
CLASSIFICATION: Stratified
- Multiple stacked layers… LIKE BRICKS!
- Good for protection
- Regenerate from basal surface
CLASSIFICATION: Pseudostratified
- MOSTLY one layer
- Cells of different sizes/shapes
NUCLEI SHAPE: Squamous
- Disc shaped central Nuclei
NUCLEI SHAPE: Cuboidal
- Large spherical (round) central Nuclei
NUCLEI SHAPE: Columnar
- Round-Oval Nuclei
Simple Squamous Epithelium:
Description:
Function:
Location:
(D, L, F:)
D: Single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm. Simplest of the epithelia
F: Allows materials to pass by diffusion and filtration in sites where protection is not important. Secretes lubricating substances in serosae
L: Air sacs of lungs