Ocular Anatomy - Fibrous tunic (Cornea & Sclera) Lab 7 & 8 Quiz

Type I

What is the main type of collagen in the cornea?

Dense regular

The cornea is made up of primarily what type of connective tissue?

Endothelium

These cells in the cornea are continuous with the cells in the trabecular meshwork of the corneoscleral angle:

False

T/F: Endothelial cells divide in vivo.

Epithelium

What component of the cornea is continuous with the conjunctiva?

Epithelium

The region in the cornea with the highest sensory innervation:

False

T/F: We have hemidesmosomes anchoring the endothelium to the stroma of the cornea.

Basal layer

The cells in the __________________________ of the epithelium have the highest mitotic activity in a normal cornea.

Epithelium

What corneal layer is damaged in a "corneal erosion?"

True

T/F: Descemet's membrane thickens with age.

Descemet's membrane

Refers to the basement membrane of the corneal endothelium:

Stroma

What part of the cornea is continuous with the sclera?

Surface layer

In what layer of the corneal epithelium do you find “tight junctions?”

Stroma

What area of the cornea is the thickest?

True

T/F: There are tight junctions between endothelial cells in the cornea.

Endothelium

What part of the cornea maintains corneal deturgescence?

Anchoring fibrils

You will find ____________________________ from the hemidesmosomes to the Bowman’s layer and the stroma.

Type IV & VIII

What type of collagen is most abundant in the Descemet’s membrane?

Limbus

Descemet’s membrane and the Bowman’s layer do not continue beyond the _____________.

Stratified squamous

What type of epithelium is the corneal epithelium?

Simple squamous

What type of epithelium is the corneal endothelium?

Basal layer

What cells in the corneal epithelium are anchored to their basement membrane via hemidesmosomes?

Tight junctions

The corneal epithelium has more ___________________________ than the corneal endothelium.

Glycoalyx

What proteins are synthesized in the corneal epithelium that help stabilize the tear film?

Basal layer

Which cell layer in the corneal epithelium is responsible for secreting the basement membrane of the epithelium?

Hemidesmosomes

The basal cells of the epithelium attach to their basement membrane via:

True

T/F: Basal cells regenerate in vivo.

Bowman's layer

What is the name of the anterior limiting lamina?

Type I

What type of collagen is found in the bowman's layer?

Descemet's membrane

What is the name of the posterior limiting lamina?

False

T/F: There are hemidesmosomes in the descemet's membrane.

Endothelium

There are plenty of Na+/K+ ATPase pumps in what part of the cornea?

Endothelium

What part of the cornea is hexagonal in shape and is continuous with the trabecular meshwork?

Dense irregular

What type of connective tissue is the sclera?

Sclerocytes

What is the name of the fibroblasts in the sclera?

Keratocytes

What is the name of the fibroblasts in the cornea?

Epithelium

Label 1

Basement membrane of the epithelium

Label 2

Bowman's layer

Label 3

Keratocytes

Label 4

Guttata

What corneal lesions are diagnostic of Fuch's corneal dystrophy?

Na+/K+ ATPase

Fuch’s corneal dystrophy causes corneal edema because the ____________________________ is blocked.

Tight junctions

Because of the absence of ____________________________, fluorescein can identify a corneal ulcer because it penetrates to the stroma.

Parallel

Collagen fibrils in the stroma are orientated ______________ to one another with regular spacing to ensure corneal transparency.

Keratocytes

The __________________ in the corneal stroma make extracellular matrix.

Extracellular matrix

Collagen fibrils and ground substance (Proteoglycans & Glycosaminoglycans) make up the __________________________ of the stroma.

Ground substance

Proteoglycans and Glycosaminoglycans make up the ______________________ in the corneal stroma.

Keratocytes

The _______________________ deplete in our stroma as we age.

Gap junctions

What type of communicating junction is present between keratocytes in the stroma?

Quiescent

Keratocytes are usually _____________ meaning they are usually inactivated until needed.

Keratocytes

In the stroma, _______________________ are activated via wound healing in which they migrate quickly to syntheize new ECM.

Keratocytes

There would be a short period of increased light scattering when ______________________ are activated in wound healing.

TGF-Beta

What type of signaling mediates the formation of myofibroblasts that cause corneal scarring?

Type III & Type V

Collagen type I fibril diameter is regulated by what other collagen types?

Posterior

Corneal edema is first seen in what part of the stroma?

Keratan sulfate

What is the most abundant corneal Glycosaminoglycan?

Type I

What type of collagen makes up dua’s layer of the cornea?

True

T/F: Dua's layer is generally considered acellular.

Dua's layer

What layer of the cornea is between the stroma and Descemet’s membrane?

False

T/F: Bowman's layer is a basement membrane.

True

T/F: Descemet's membrane can be dissected as a continuous sheet.

True

T/F: The basal lamina of Descemet's membrane can regenerate.

False

T/F: The Bowman's layer thickens as we age.

Epithelium

Zonula occludens are located in what layer of the cornea?

Endothelium

Macula occludens are located in what layer of the cornea?

Schwalbe's line

What is the most anterior structure in the angle of the eye?

Descemet's membrane

The schwalbe’s line indicates the end of the ________________________________ in which it terminates at the limbal region.

False

T/F: There are elastin fibers in Descemet's membrane.

Hexagonal

What is the shape of a normal healthy endothelial cell in the cornea?

Macula occludens

What is the name of the more leaky tight junctions found in the endothelium?

True

T/F: Corneal epithelial cells store glycogen.

False

T/F: The corneal endothelium has hemidesmosomes.

True

T/F: There are gap junctions in the corneal endothelium.

Endothelium

Which layer of the cornea has cells that are metabolically very active?

Hemidesmosomes

The basal cells of the corneal epithelium attach to the basement membrane via:

Anchoring fibrils

The epithelial basement membrane of the cornea attaches to the Bowman’s layer via:

Basal layer

The ____________________ of the corneal epithelium is columnar in shape and only one cell thick.

Surface layer

What layer of the epithelium of the cornea produces glycocalyx?

Wing layer

What is the intermediate layer of the epithelium of the cornea which is polyhedral/polygonal in shape and has cells with a large ovoid nucleus?

Endothelium

Which part of the cornea is bathed by the aqueous humor?

True

T/F: The cornea is steeper in the center than the periphery.

False

T/F: The cornea is thicker in the center than the periphery.

Surface layer

In what layer of the corneal epithelium is there microvilli present?

Type VII

What type of collagen forms the anchoring fibrils?

True

T/F: The Bowman's layer appears to contribute to corneal shape.

Keratocytes

Confocal microscopy in the living eye shows numerous ______________________ at the level of Bowman’s layer, even though it was originally considered acellular.

True

T/F: You would find hemidesmosomes in the basement membrane of the corneal epithelium.

False

T/F: Descemet's membrane is continuous with the limbus.

Epithelium

Label 1

Bowman's layer

Label 2

Stroma

Label 3

Dua's layer

Label 4

Descemet's membrane

Label 5

Endothelium

Label 6

Surface layer

Label 1

Wing layer

Label 2

Basal layer

Label 3

Basement membrane of the epithelium

Label 4

Bowman's layer

Label 5

1 cell

How many cells thick is the basal layer of the epithelium?