OPT 114 Cornea UPDATED ACTUAL
Questions and CORRECT Answers
What components make up the ocular surface? - CORRECT ANSWER - Conjunctiva and
cornea
What makes cornea different than conjunctiva in appearance? - CORRECT ANSWER -
Avascular
What are the layers of the cornea (outer to inner)? - CORRECT ANSWER - epithelium,
Bowman's layer, stroma, (Dua's Layer), Descemet's membrane, and endothelial
What is the central thickness of cornea? - CORRECT ANSWER - 0.53 mm to .55mm
(530nm to 550nm)
What is peripheral thickness of cornea? - CORRECT ANSWER - 0.71mm
What are you at risk for if you have a thinner cornea? - CORRECT ANSWER - Glaucoma
What is the function of the epithelium of cornea? - CORRECT ANSWER - Barrier to the
outside environment
If someone gets a cut on the cornea, what do they need to be prescribed to prevent infection? -
CORRECT ANSWER - Antibiotic
Describe the epithelial cells based on their progressive stages of differentation - CORRECT
ANSWER - Basal cells-mitosis and migrate into outer cells
Wing cells-transition zone
Surface cells- apical cells
, What is the structure of basal cells? - CORRECT ANSWER - single layer of columnar
cells
When basal cells move up and become wing cells, what replaces them? - CORRECT
ANSWER - Limbal stem cells
What are the characteristics of surface cells of epithelium? - CORRECT ANSWER - -2
layers of non-keratinized, squamous cells
-microvilli
-secrete the glycocalyx
-tight junctions join lateral sides of adjacent cells
-undergo desquamation
What is the function of microvilli of surface cells? - CORRECT ANSWER - Increase
surface area and help bind mucin to the corneal surface
What are glycocalyx? - CORRECT ANSWER - Transmembrane mucins (glycoproteins)
that are MUC1, MUC4, and MUC16
What are the functions of glycocalyx? - CORRECT ANSWER - Functions are barrier to
pathogens and injury, helps bind mucin to the corneal surface, and helps spread the tear film
across the corneal surface
What are the functions of tight junctions between adjacent surface cells? - CORRECT
ANSWER - Forms a complete barrier preventing fluid and molecules from passing
between cells. Fluid and molecules must pass through cells.
What would happen if fluid came into cornea? For example, if the tight junctions were damaged.
- CORRECT ANSWER - Tear film would come into the cornea and make vision blurry
Questions and CORRECT Answers
What components make up the ocular surface? - CORRECT ANSWER - Conjunctiva and
cornea
What makes cornea different than conjunctiva in appearance? - CORRECT ANSWER -
Avascular
What are the layers of the cornea (outer to inner)? - CORRECT ANSWER - epithelium,
Bowman's layer, stroma, (Dua's Layer), Descemet's membrane, and endothelial
What is the central thickness of cornea? - CORRECT ANSWER - 0.53 mm to .55mm
(530nm to 550nm)
What is peripheral thickness of cornea? - CORRECT ANSWER - 0.71mm
What are you at risk for if you have a thinner cornea? - CORRECT ANSWER - Glaucoma
What is the function of the epithelium of cornea? - CORRECT ANSWER - Barrier to the
outside environment
If someone gets a cut on the cornea, what do they need to be prescribed to prevent infection? -
CORRECT ANSWER - Antibiotic
Describe the epithelial cells based on their progressive stages of differentation - CORRECT
ANSWER - Basal cells-mitosis and migrate into outer cells
Wing cells-transition zone
Surface cells- apical cells
, What is the structure of basal cells? - CORRECT ANSWER - single layer of columnar
cells
When basal cells move up and become wing cells, what replaces them? - CORRECT
ANSWER - Limbal stem cells
What are the characteristics of surface cells of epithelium? - CORRECT ANSWER - -2
layers of non-keratinized, squamous cells
-microvilli
-secrete the glycocalyx
-tight junctions join lateral sides of adjacent cells
-undergo desquamation
What is the function of microvilli of surface cells? - CORRECT ANSWER - Increase
surface area and help bind mucin to the corneal surface
What are glycocalyx? - CORRECT ANSWER - Transmembrane mucins (glycoproteins)
that are MUC1, MUC4, and MUC16
What are the functions of glycocalyx? - CORRECT ANSWER - Functions are barrier to
pathogens and injury, helps bind mucin to the corneal surface, and helps spread the tear film
across the corneal surface
What are the functions of tight junctions between adjacent surface cells? - CORRECT
ANSWER - Forms a complete barrier preventing fluid and molecules from passing
between cells. Fluid and molecules must pass through cells.
What would happen if fluid came into cornea? For example, if the tight junctions were damaged.
- CORRECT ANSWER - Tear film would come into the cornea and make vision blurry
