What is the histology of the sclera?
What is the histology of the sclera?
The sclera is dense connective tissue made of mainly type 1 collagen fibers, oriented in different directions. However, the collagen of the sclera and cornea are continuous. The four layers of the sclera from external to internal are episclera, stroma, lamina fusca, endothelium.
What is conjunctival epithelium?
The conjunctival epithelium is a non-keratinized, stratified columnar epithelium that lines the inside of the eyelids and covers the sclera. The conjunctiva contains goblet cells that secrete mucin, which generates the moisture that covers the surface of the eye and allows the eyelids to open and close easily.
What are the layers of the conjunctiva?
Microscopically conjunctiva consists of three layers- epithelium, adenoid layer, and a fibrous layer.
- Conjunctival Epithelium:
- Substantia propria or conjunctival submucosa:
- Fibrous layer:
What is conjunctiva made of?
The conjunctiva is composed of a non-keratinizing stratified columnar epithelium and an underlying layer of loose connective tissue, the substantia propria. The fornices and palpebral conjunctival epithelium are rich in goblet cells, which produce mucin.
Why is the cornea transparent histology?
The transparency of the cornea is based primarily on the regularity of its tissue components, which minimizes the scattering of light. Both outer and inner surfaces of the corneal epithelium are smooth.
Why is my sclera blue?
Blue sclera is caused by a congenitally thinner-than-normal sclera or a thinning of the sclera from disease, which allows the color of the underlying choroidal tissue to show through it.
What are the three sections of the conjunctiva?
The conjunctiva can be divided into three regions: the palpebral or tarsal conjunctiva, the bulbar or ocular conjunctiva, and the conjunctival fornices. The palpebral conjunctiva is further divided into the marginal, tarsal, and orbital regions. The bulbar conjunctiva is divided into scleral and limbal parts.
What is the structure of conjunctiva?
The conjunctiva consists of unkeratinized, both stratified squamous and stratified columnar epithelium, with interspersed goblet cells. The epithelial layer contains blood vessels, fibrous tissue, and lymphatic channels. Accessory lacrimal glands in the conjunctiva constantly produce the aqueous portion of tears.
What is palpebral conjunctiva?
Palpebral conjunctiva: The part of the conjunctiva, a clear membrane, that coats the inside of the eyelids. The palpebral conjunctiva is as opposed to the ocular (or bulbar) conjunctiva, the part of the conjunctiva that covers the outer surface of the eye.
