Histology Epithelial Tissues Flashcards
4 basic epithelium tissues
- Epithelial tissues
- Connective tissues
- Muscle tissues
- Nervous tissues
Which tissue type responds to stimuli?
Nervous tissue
Parenchyma
Functional tissue (epithelium)
Stroma
Support tissue (connective tissue)
Apical surface of epithelium
Long microvilli, facing lumen or outside
Lateral surface of epithelium
Where epithelial cells interconnect, lots of intracellular junctions
Basal surface of epithelium
Bottom, where epithelial cells connect to underlying connective tissue. Basal lamina is secreted by epithelial cells and binds CT
Junctional complex (location and parts)
Right underneath microvilli:
• Zona Occludens (tight junctions) - prevents things from surface from getting inside
• Zonula adherans (intermediate junction)
• Macula adherens (desmosome) - spot welds holding cells together
• Hemi desmosomes - connect to basal lamina
Basal lamina (function)
Separates epithelium from underlying tissue
Basal lamina (parts)
epithelium makes Lamina rare and Lamina densa. Underlying CT makes Lamina reicularis.
Can you see microvilli (actin filaments) under light microscope?
No, you can only see the brushed border effect
Can you see Cilia under light microscope?
Yes, cilia is bigger than microvilli b/c it has microtubules. 9 doublets plus 2 center microtubules)
Epithelial classification I
Squamous, Cuboidal, Columnar
Epithelial classification II
Simple epithelium, Stratified epithelium, Pseudostratified (all cells on basal, only some reach apex)
Transitional type of epithelium
Stratified, but looks cuboidal when compressed/collapsed
