Histology: Epithelium Flashcards
What are the 6 basic characteristics of epithelial tissue?
Cellularity
Polarity
Attachement
Avascular
Innervation
Regeneration
Epithelial Polarity:
What is the basal domain?
Rests on the basal lamina, anchors cell to underlying connective tissue
Epithelial Polarity:
What is the apical domain?
Directed toward the exterior
Epithelial Polarity:
What is the Lateral domain?
Communicates with adjacent cells
What are the (4) types of apical specializations?
- Cilia
- Flagella
- Microvili
- Stereocilia
What are microvili?
-Correlate to absorptive capacity
-Actin based
-Can be up to 100k on single cell
What are stereocilia/stereovilli?
- Unusually long and immotile
- Actin core
- ONLY IN: epididymis and sensory cells of inner ear
What are cilia?
Describe the 3 subcategories
- Microtubule based
1. Motile: wave-like fashion, remove debris
2. Primary: immotile, chemosensors, osmosensors, mechanosensors
3. Nodal: embryonic
What are flagella?
- Motile cilia
- Provides forward movement for sperm cell
Intercellular Junctions:
What are occluding junctions?
- Impermeable
- Near most apical surface
- More junctions=lower permeability
*OCCLUDINS, CLAUDINS
Intercellular Junctions:
What are anchoring junctions?
2 types:
- Zonula Adherens: interacts w/ actin
- Maculae Adherens: (Desmosomes) interacts with intermediate filaments
Intercellular Junctions:
What are gap junctions?
- Communication
- *connexin aggregates
Intercellular Junctions:
What are focal adhesions?
Anchor actin filaments to basement membrane
*use INTEGRINS
Intercellular Junctions:
What are hemidesmosomes?
-Anchor intermediate filaments to basement membrane
*use INTEGRINS
Multiple layers in epithelia is named?
Stratified
Single layer of epithelium named?
Simple epithelium
Epithelium classified by shapes:
What are the classifications (3)?
Table of classificaiton of epithelia:
Identify this:
Simple Squamous Epithelium
Where are simple squamous cells found?
Lining of blood and lymphatic vesseles
What is the function of simple squamous cells?
Exchange, barrier and lubrication
What is this?
Simple squamous epithelium
Simple squamous:
Where found in endothelium?
lining of serous membranes