Week 2 Epithelial tissue histology Flashcards
What ar4 basic tissue types?
Epithelial, connective, muscular, neural
Does epithelium have blood vessels?
No
Which surfaces of epithelial cells are specialised for communication?
Lateral and basal
What is the epithelium called on serosa?
Mesothelium
What does serosa line?
Body cavities and covers organs
Apcial surface modifcations of epithelial cells
Microvilli, cilia, stereocilia
Features of microvilli? Where found?
Actin filaments, + surface area. guts, kidney tubules. ABSORPTION
Features of Cilia? Where found?
Microtubules (doublets + dynein protein), move secretions, motile. airways, sperm.
Features of Sterocilia. Where found?
actin filaments, + surface area/ epididymus, inner ear
What is the core of cilia made from?
Axoneme (9+2 pattern of microtubule doublets)
What is at the terminal bar of epithelial cells?
Junctional complexes
What are the components of the Junctional Complex?
Zonula occludens, zonula adherens, macula adherens
Function of zonula occludens?
Tight junctions - draws neighboring cell membranes close. Adhesion & selective movement of ions and water thru intercellular space.
What filaments are linked in zonula occludens?
Actin filaments
Function of zonula adherens?
Lateral adhesion - Reinforces against mechanical stress. uniform 15nm between cells
Function of macula adherens?
Desmosome - strong attachment site between cells. Intercellular space = 30nm.
What filaments connect to desmosomes?
Intermediate filaments
What is lateral communication of cells mediated by?
Gap junctions - 6 proteins, circular channel
T or F: Gap junctions are constantly open
False - open and close
What is the function of the basement membrane?
Influences cell differentiation, regeneration, motility and shape. barrier,
How do epithelial cells attach to basement membrane?
Hemidesmosomes
