Epithelia Flashcards
Why is it important that epithelial cells divide rapidly?
- To have a quick turnover –> due to damage, infection
Primary cilia
Non-motile, present in non-dividing cells
Mucous glands
- structure x2
- Flat, dense nuclei
- Foamy cytoplasm
Serous glands
- structure x2
- Round vesicular nuclei
- Eosinophilic cytoplasm
Simple epithelium occurs where….
There’s diffusion, absorption, secretion etc.
Stratified epithelium occurs where…
Protection is needed (as there are more layers)
Qualities of simple squamous x4
- Single layer
- Thin flattened cells w central nucleus
- Close proximity (no gaps)
- Some secretion
Mesothelium
- type of endothelium
- where
- function
- example
- simple squamous
- lines body cavities
- secretes fluid –> less friction
- e.g. pleura, peritoneum
Endothelium
- type of endothelium
- where
- function
- variations in structure…
- simple squamous
- lines blood vessels
- secretes fluid –> less friction
- can be almost impermeable vs having fenestrae (allows different molecules through)
Blood brain barrier
- function x2
- Protects brain from infection
- Restricts passage of potentially harmful molecules
BUT - Allows essential ones through (O2, nutrients, ALSO drugs, alcohol etc)
Qualities of simple cuboidal x2
- Round, central nucleus
- Approx. equal height & width
Qualities of simple columnar x1
- Basal nucleus
Small Intestine
- type of epithelium
- where specifically
- why this one
- surface modifications x2
- Simple columnar
- Villi
- More cytoplasm = more organelles for secretion/active transport
- Microvillus brush border on apical surface
- Goblet cells = release mucus, stopping pathogens binding
Modified columnar epithelium
- examples & their modification x2
- Villi (GI tract) –> + goblet cells & microvillus brush border
- Kidney –> microvillus brush border
Qualities of pseudo-stratified columnar epithelium
Appears to have multiple layers, but just nuclei at different levels, as not all cells reach the apex
Respiratory epithelium
- type of epithelium
- types of cells
- adaptation
- Pseudo-stratified ciliated columnar
- Columnar, goblet, basal
- Cilia –> protection –> as pathogens transported upwards towards larynx