Lab 2: Part 2: Introduction to the Tissues: Epithelial Tissues Flashcards
(26 cards)
Epithelial Tissue characteristics
- make excellent barriers due to closely packed cells
- avascular
- innervated
- regenerative
avascular
contain no blood vessels
innervated
connected to the nervous system
regenerative
worn out and dead cells continually replaced
Epithelia are classified based on these two criteria:
- Number of layers
- Cell shape
The different layers
- simple
- pseudostratified
- stratified
Layer: Simple
one layer
Layer: Pseudostratified
falsely layered
Layer: Stratified
many layers
Shape: Squamous
flat (squished looking nucleus)
Shape: Cuboidal
cube (perfect circled nucleus)
Shape: Columnar
tall (stretched nucleus)
Basal surface
bottom edge of the epithelial tissue
Apical surface
edge of the epithelial tissues facing the external environment (top)
Simple Squamous function?
- filtration
- diffusion
- rapid exchange of materials
Simple Squamous location?
- air sacs of the lungs
- kidney filtration membranes
- lines blood vessels
Simple Cuboidal function?
-secretion
Simple Cuboidal location?
- kidney tubules
- glands
Simple Columnar function?
- secretion
- absorption
Simple Columnar location?
- lining of the spinal cord and brain (ciliated)
- lines GI tract
- kidney ducts
Pseudostratified Columnar function? (has cilia)
- secretion
- may be ciliated or non-ciliated
Pseudostratified Columnar location?
-respiratory tract
Stratified Squamous function?
- protection (adhesion, water loss, UV radiation)
- 1st line of defense against microbes
Stratified Squamous location?
- keratinized found in the superficial (external) layer of skin
- non-keratinized lines wet surfaces (mouth, esophagus)
