Epithelial cell specializations Flashcards
What are apical cell surface specializations?
Microvilli
Sterocilia
Cilia
What are lateral cell surface specializations?
Occluding junctions
Adhering junctions
Communicating junctions
Membrane plicae
What are basal cell surface specializations?
Basal lamina
Basal striations
What is the function of microvilli?
Increase the surface area of the cell.
What is the terminal web?
A web of actin below microvilli that can translate movement inside the cell to the microvilli
The _____ and _____ of the cell’s microvilli reflect the cell’s absorptive capacity.
Number and shape
What is the core of the microtubule called?
Axoneme
What is the morphology of a microtubule?
“9 + 2” - 9 peripheral pairs of microtubules and one central one.
Each pair = A and B component with dynein arms
From where does the axoneme grow?
The basal body, a short cylinder of 9 microtubule triplets
What are stereocilia and what is their functin?
Very long microvilli
Stereocilia in the ductus epididymis function to absorb luminal fluids.
Is cilia beating coordinated between cells?
Yes!
What is the function of beating cilia?
To move material parallel to the surface
What are the functions of intercellular junctions?
Occluding
Adhering
Communicating
What is the occluding junction and what is its function?
Zonula occludens/tight junction
Prevents the passage of material between adjacent cells and keeps the apical membrane domain separate from the basolateral domain.
What are macula adhering junctions/desmosomes?
Spot adherens
What are fascia adherens?
A sheat of adhesion (found in heart)
What are zonula adherens?
A belt of adhesion