VAN 121: Veterinary Gross Anatomy-II (2+2)

CORNEA

• The cornea forms the anterior one fifth of the fibrous tunic.
• It is transparent, colorless, and avascular. It is oval, the broad end being medial.
• The anterior surface is convex and more curved than the sclera. The posterior surface is concave and forms the anterior boundary of the anterior chamber.
• The margin joins the sclera where the sclera overlaps the cornea.

Structure

• Corneal epithelium lined stratified squamous epithelium.
• Lamina limitans anterior or Bowman’s membrane which is very thin and homogeneous.
• Substantia propria -lamellae of connective tissue with connective tissue corpuscles-the corneal corpuscles that are transparent.
• Lamina elastica or Descemet’s membrane- a thick, elastic homogeneous membrane. This lamina divides at the periphery into three divisions, the anterior part joins the sclera; the middle one gives attachment to the ciliary muscle and posterior division passes to the iris forming the ligamentum pectinatum iridis.
• Endothelium of squamous cells; this after lining the cornea is reflected over the iris.

Note

• All the layers forming the cornea are transparent.

Blood Supply

• Cornea is devoid of blood vessels. It derives nutrition from the superficial plexus of vessels.

Nerve Supply

• Ciliary nerves.