Exam 1 Remington- Cornea Flashcards Preview

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Flashcards in Exam 1 Remington- Cornea Deck (123)
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31

Zonular

Belt-like goes all the way around cell

32

Macular

Spot-like

33

What are the 2 types of intercellular junctions?

Adhering and occluding

34

Adhering intercellular junction

Narrow intercellular space, transmembrane adhesion molecules, and contributes to cell stability

35

Occluding intercellular junction

Focal fusion of outer leaflet of plasma membranes, seals off intercellular space (NOTHING gets through)

36

What is a terminal bar?

Adjacent ZO + ZA

37

Desmosomes

Circular attachment plaque, filaments extend into cellular cytoplasm, adhesive mucoprotein fills intercellular space

38

Hemidesmosomes

Attachment of basal surface to underlying CT, filaments join intercellular plaque to plaque in CT

39

Gap junctions

Kind of tube, sends from one cell to the next rapidly

40

Connexon

Transmembrane channel or pore

41

What does a connexon do?

Joins cytoplasm of adjoining cells

42

A connex___ is composed of 6 protein connex___

-on, -in

43

What do gap junctions do?

Permits passage of small molecules, nutrients, and ions

44

Glycocalyx

Gycoprotein covering surface of the cell

45

The corneal epithelium consists of what kind of cells?

Stratified squamous

46

What does the surface layer of the corneal epithelium consist of?

Non-keratinized, microvilli, glycocalyx, intercellular junctions (desmosomes and zonular occludens)

47

What is the function of zonular occludens in the intercellular junctions?

Semi-permeable membrane

48

What is the purpose of fluorescein straining in evaluating the corneal epithelial surface?

Evaluates the barrier function of the surface layer

49

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.

50

What is in the wing cell layer of the corneal epithelium?

Intercellular junctions ( desmosomes and gap junctions), DOES NOT contain ZO

51

What is known as the transition layer of the corneal epithelium?

Wing cell layer

52

What is known as the germinative layer of the corneal epithelium?

Basal layer

53

What intercellular junctions are in the basal layer of the corneal epithelium?

Desmosomes, gap junctions, hemidesmosomes

54

What secretes the basal lamina portion of the BM?

Basal layer

55

In hemidesmosomes, fibrils attach to _____ in stroma

Plaques

56

What do plaques contain?

Laminin

57

What are two causes of recurrent corneal erosion?

EBMD ( epithelial basement membrane dystrophy) and incomplete healing of abrasion

58

Dystrophy

Condition caused by defective nutrition or metabolism, also malformed hemidesmosomes

59

What are signs and symptoms of recurrent corneal erosion?

Areas of sloughed epi, pain

60

What is the treatment of recurrent corneal erosion?

Bandage contact lens and corneal puncture