Histology of Epithelia Flashcards
What do you know about a single layer of epithelia
Squamous
Easy diffusion
Can be cuboidal - secretory
Can be columnar - absorption
What do you know about stratified layer of epithelia
Prevent water loss
Secretion
Protection
What do you know about pseudostratified layer of epithelia
Nuclei at different heights to give illusion of multiple layers
Ciliated
Upper respiratory tract
What determines classification of tissue
Top layer (apical)
Why does epithelia lie over connective tissue
Connective tissue supplies nutrients as it has the blood vessels
What is a tight junction
Lie beneath apical pole, run around cell
Forces nutrients to go through cell not in between
Stops ion channels from moving from top to bottom
What is function of adherins
Adhesion between cells
What is a desmosome
Disk shaped structure at surface of one cell that is matched with an identical structure on adjacent
What is a gap junction
A haxameric connexon
What is the function of hemidemosomes
Bind cells to basal lamina
What is the difference between microvilli, cilia and stereocilia
Microvilli = random and not motile. Actin filaments Stereocilia = longer than microvilli+ less motile than cilia Cilia = elongated + highly motile. Highly organised structure. 9 peripheral microtubules
What occurs to the urothelium when bladder is full or empty
Full bladder = distended
Empty spaces = non-distended.
What is eccrine secretion
Exocytosis of protein or glycoprotein
What is holocrine secretion
Cells fill up with secretory product, then burst
What is apocrine secretion
Secretory product secreted with apical cytoplasm
