What is the anatomy of eyelid?
What is the anatomy of eyelid?
Each eyelid contains a fibrous plate, called a tarsus, that gives it structure and shape; muscles, which move the eyelids; and meibomian (or tarsal) glands, which secrete lubricating fluids. The lids are covered with skin, lined with mucous membrane, and bordered with a fringe of hairs, the eyelashes.
What are the 4 layers of the eyelid?
Upper eyelid (Fig. 2–6) (mnemonic: 4-5-7 rule): The lower 5 mm has 4 layers: skin, orbicularis, tarsus, and conjunctiva.
What are the three layers of the eyelid?
Upper eyelid anatomy: It is clinically useful to divide the anatomical structures in the upper lid into three layers – the superficial anterior lamella, middle lamella and the posterior lamella.
What is GREY line of eyelid?
Gray Line (Intermarginal sulcus) The gray line of the eyelid margin represents the most superficial portion of the palpebral (pretarsal) orbicularis oculi muscle, the muscle of Riolan.
What are the types of eyelids?
The upper lid crease can be divided into three types: (1) a single eyelid (no visible lid crease), (2) a low eyelid crease (low-seated, nasally tapered, including hidden fold), and (3) a double eyelid (well-formed supratarsal crease).
How many muscles are in the eyelid?
The muscles of the eyelids are: Levator palpebræ superioris. Orbicularis oculi. Corrugator.
What is upper eyelid called?
There are two points at which the upper and lower eyelids meet. The one on the inner aspect is called the medial canthus and the one on the outer aspect is called the lateral canthus.
What is Monolids?
Monolid eyes, or epicanthal folds, are an eyelid shape commonly seen in people of Asian descent. It’s also seen in people with genetic conditions. With monolid eyes, the skin of your upper eyelids covers the inner parts of your eyes. You don’t have folds dividing your eyelids into two parts.
What is eye shape called?
There are six main eye shapes — round, monolid, hooded, downturned, upturned and almond — and they’re all fabulous in their own way. You may have also heard the following descriptions for your eyes: wide set, asymmetrical, big, small, close set and deep set.
What nerve opens the eyelid?
The oculomotor nerve
The oculomotor nerve (CNIII) innervates the main upper eyelid retractor, the levator palpebrae superiorus, via its superior branch.