Flashcards in Exam 1 Remington- Cornea Deck (123)
Belt-like goes all the way around cell
What are the 2 types of intercellular junctions?
Adhering and occluding
Adhering intercellular junction
Narrow intercellular space, transmembrane adhesion molecules, and contributes to cell stability
Occluding intercellular junction
Focal fusion of outer leaflet of plasma membranes, seals off intercellular space (NOTHING gets through)
What is a terminal bar?
Adjacent ZO + ZA
Circular attachment plaque, filaments extend into cellular cytoplasm, adhesive mucoprotein fills intercellular space
Attachment of basal surface to underlying CT, filaments join intercellular plaque to plaque in CT
Kind of tube, sends from one cell to the next rapidly
Transmembrane channel or pore
What does a connexon do?
Joins cytoplasm of adjoining cells
A connex___ is composed of 6 protein connex___
What do gap junctions do?
Permits passage of small molecules, nutrients, and ions
Gycoprotein covering surface of the cell
The corneal epithelium consists of what kind of cells?
What does the surface layer of the corneal epithelium consist of?
Non-keratinized, microvilli, glycocalyx, intercellular junctions (desmosomes and zonular occludens)
What is the function of zonular occludens in the intercellular junctions?
What is the purpose of fluorescein straining in evaluating the corneal epithelial surface?
Evaluates the barrier function of the surface layer
What happens when fluorescein is instilled in the tear film?
Flurescein will not penetrate the epithelial tissue as long as ZO are intact. If disrupted, dye can pass through Bowman's layer into the anterior stroma.
What is in the wing cell layer of the corneal epithelium?
Intercellular junctions ( desmosomes and gap junctions), DOES NOT contain ZO
What is known as the transition layer of the corneal epithelium?
Wing cell layer
What is known as the germinative layer of the corneal epithelium?
What intercellular junctions are in the basal layer of the corneal epithelium?
Desmosomes, gap junctions, hemidesmosomes
What secretes the basal lamina portion of the BM?
In hemidesmosomes, fibrils attach to _____ in stroma
What do plaques contain?
What are two causes of recurrent corneal erosion?
EBMD ( epithelial basement membrane dystrophy) and incomplete healing of abrasion
Condition caused by defective nutrition or metabolism, also malformed hemidesmosomes
What are signs and symptoms of recurrent corneal erosion?
Areas of sloughed epi, pain