What Is the Conjunctiva?
A layer of mucous covering the upper and lower eyelids and in front of the eyeballs. It is a transparent film formed by stratified columnar epithelium and a small amount of connective tissue. The lining of the eyelid is the conjunctiva, and the bulbous conjunctiva is placed in front of the eyeball. The two parts are continuous with each other. When the eyelid is closed, the space surrounded by the conjunctiva is called "conjunctival sac". It has the effect of protecting and facilitating eye movement. The transition between the bulbar and conjunctiva is called the fornix conjunctiva. The conjunctiva is rich in blood vessels and nerve endings, and has a small number of mucous glands, which can secrete mucus and smoothen the eyeballs to reduce friction between the eyelid conjunctiva and the cornea. Chlamydia trachomatis mainly invades the conjunctiva and fornix conjunctiva. Acute bacterial conjunctivitis and viral conjunctivitis are caused by bacteria and viruses that infect the conjunctiva and are both contagious.
- Chinese name
- conjunctiva
- Foreign name
- conjunctiva
- Nature
- Smooth and transparent film
- Function
- Increase immunity
- A layer of mucous covering the upper and lower eyelids and in front of the eyeballs. It is a transparent film formed by stratified columnar epithelium and a small amount of connective tissue. The lining of the eyelid is the conjunctiva, and the bulbous conjunctiva is placed in front of the eyeball. The two parts are continuous with each other. When the eyelid is closed, the space surrounded by the conjunctiva is called "conjunctival sac". It has the effect of protecting and facilitating eye movement. The transition between the bulbar and conjunctiva is called the fornix conjunctiva. The conjunctiva is rich in blood vessels and nerve endings, and has a small number of mucous glands, which can secrete mucus and smoothen the eyeballs to reduce friction between the eyelid conjunctiva and the cornea. Chlamydia trachomatis mainly invades the conjunctiva and fornix conjunctiva. Acute bacterial conjunctivitis and viral conjunctivitis are caused by bacteria and viruses that infect the conjunctiva and are both contagious.
Conjunctival Overview
- The conjunctiva is a transparent phenanthrene mucosa, soft, smooth and elastic, covering the inner surface of the eyelid (conjunctiva), part of the surface of the eyeball (bulbar conjunctiva), and the reflexed part from the eyelid to the bulb (bulbar conjunctiva). These three parts of the conjunctiva form a sac-like space with an opening of the eyelid, called the conjunctival sac.
Classification of conjunctiva
- 1). Conjunctiva.
- 2). Ball conjunctiva: It covers the surface of the sclera in the front of the eyeball. It has a loose attachment and can be moved. It is the thinnest and most transparent part of the conjunctiva. The bulbar conjunctiva and the sclera are loosely connected to the eyeball fascia, and are fused with the ball fascia and sclera within 3mm near the limbus. On the temporal side of the lacrimal fungus, there is a half-lunar conjunctival fold called a semilunar fold, which is equivalent to the third eyelid of lower animals.
- 3). Fornix conjunctiva: It is a wrinkle part where the conjunctiva and bulbar conjunctiva migrate to each other; the loose tissue is conducive to the free rotation of the eyeball. The upper fornix is entangled with upper levator muscle fibers, and the lower fornix is infused with lower rectus sheath fibers.
- The conjunctiva is a mucosa that is histologically composed of non-keratinized squamous epithelium and goblet cells, with an epithelial layer and a lamina propria. The epithelium has 2 to 5 layers, and the thickness and cell morphology of each part are different. The edge of the eyelid is flat epithelium, the meibomian to dome portion gradually transitions from cubic epithelium to cylindrical shape, the bulbar conjunctiva is flat, the corneal limbus gradually becomes stratified squamous epithelium, and then transitions to corneal epithelium. Goblet cells are single-cell mucinous glands, mostly distributed in the epithelial cell layer of the conjunctiva and fornix conjunctiva, secreting mucus. The lamina propria contains blood vessels and lymphatic vessels, and is divided into adenoid and fibrous layers. The adenoid layer is thinner and the dome is well developed. It contains Krause gland, Wolfr gland, and secretes serous fluid. This layer is composed of a thin network of connective tissue, with a large number of lymphocytes, which easily form follicles during inflammation. The fibrous layer is composed of collagen fibers and elastic fibers, and the conjunctiva is lacking.
- The conjunctival vessels come from the eyelid artery arch and the anterior ciliary artery. The palpebral artery passes through the meibomian plate and is distributed in the conjunctiva, fornix, and bulbar conjunctiva 4mm away from the corner of the conjunctiva. Congestion is called congestion when it is congested. The anterior ciliary artery divides a small upper branch of the sclera at the edge of the cornea sclera 3 to 5mm, forming a vascular network around the limbus, and distributed in the bulbar conjunctiva. When it is congested, it is called ciliary congestion. Two different types of congestion are of great significance for the judgment of eye lesions.