Epithelium & Glands Flashcards
(25 cards)
Basement Membrane
connects the epithelia and connective tissue
2 Portions of Basement Membrane
Basal Lamina
Reticular Lamina
Basal Lamina
layer of ECM secreted by epithelial cells that is part of the basement membrane
Reticular Lamina
reticular fibers that aid in anchoring the connective tissue to the basal lamina
2 Portions of Basal Lamina
Lamina Lucida
Lamina Densa
Lamina Lucida
- found between the basal layer of cells and the lamina densa
- light region in microscope
Lamina Densa
- found between the lamina lucida and connective tissue
- dark region in microscope
Zonulae Occludens (Tight Junctions)
between adjacent plasma membranes, preventing external materials from penetrating these cells
Zonulae Adherents (Adherens Junctions)
forms belt-like structure that acts like an anchoring mechanism
Desmosomes
disc shaped plaques that are located within the cytoplasm of adjacent cells which contain attachment proteins that form bridges between adjacent cells
-permeable to water and helps resist shear forces
Hemidesmosomes
half desmosomes that attach basal cell membrane to the basal lamina
Gap Junctions
transmembrane proteins, form connections or aqueous pores within the membrane allowing materials or signals to pass through cell to cell
Goblet Cells
- glandular simple columnar epithelial cells (unicellular) whose function is to secrete mucins, thus lubricating and protecting epithelial sheet
- sit at basal region of basal lamina and extend into the lumen
Microvilli
cylindrical, fingerlike projections of plasma membrane that do not move but help to increase surface area for absorption
Stereocilia
long, non-motile processes that are branched microvilli (not true cilia)
Cilia
- small, thick motile projections that extend off of epithelial cells
- involved in sensory functions and movement of mucus
- 9+2 doublet arrangement
Flagella
motile tail projection that aids in locomotion
Exocrine
release externally (ex. in lumen)
Endocrine
release internally (ex. into blood)
Mucus Glands
- secrete glycoprotein solution (mucin)
- appear clear and light
Serous Glands
- secrete clear, watery enzyme solution
- appear dark
Serous Demilunes
glands that contain both mucus and serous cells
Merocrine
secreted through exocytosis into an epithelial-walled duct or into the lumen (VESICLES)
Holocrine
produced in cytoplasm of cell and are released into lumen through rupturing of cell membrane, destroying the cell (SACRIFICE)
