Information about Eyelid
) | |
| Upper eyelid | |
| Latin | palpebra inferior, palpebra superior |
| subject #227 1025 | |
| Artery | lacrimal, superior palpebral, inferior palpebral |
| Nerve | upper: infratrochlear, supratrochlear, supraorbital, lacrimal lower: infratrochlear, branches of infraorbital |
| MeSH | Eyelids |
Anatomy
Layers
In the human eyelid, there are various layers; from superficial to deep, they are: skin, subcutaneous tissue, orbicularis oculi, orbital septum & tarsal plates, and palpebral conjunctiva. The meibomian glands lie within the eyelid and secrete the lipid part of the tearfilm.Innervation
In humans, the sensory nerve supply to the upper eyelids is from the infratrochlear, supratrochlear, supraorbital and the lacrimal nerves from the ophthalmic branch (V1) of the trigeminal nerve (CN V). The skin of the lower eyelid is supplied by branches of the infratrochlear at the medial angle, the rest is supplied by branches of the infraorbital nerve of the maxillary branch (V2) of the trigeminal nerve.Blood supply
In humans, the eyelids are supplied by two arches on each upper and lower lid. The arches are formed by anastamoses of the lateral palpebral arteries and medial palpebral arteries, branching off from the lacrimal artery and ophthalmic artery, respectively.Usage
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Blinking eye
Most animals with eyelids have a reflex to close the eyes when a threat comes too near. This is done involuntarily to protect the eye from contact with the threat. It is often strong enough to overcome any voluntary resistance.
Eyelids also serve the purpose of helping the animal to control the amount of light entering the eye (control of the iris is autonomic). Without eyelids, many animals would be helpless to block visual sensory overload under very bright light. Many animals also use eyelids to block light from reaching the eyes during sleeping cycles.
Types
In humans, each eye has an upper and lower eyelid which operate as a pair, however, it is primarily the upper eyelid that moves across the exposed surface of the eye during blinking. Lower eyelids in most animals move vertically.Many terrestrial vertebrates have an eyelid known as a nictitating membrane, or haw. This eyelid is closer to the eye than the outer lids and is usually transparent. The purpose of the nictitating membrane is to add protection to the eye from debris and irritation, and in land animals it also serves as a barrier while swimming. Camels, crocodiles, cats, birds, and polar bears are among animals that have this membrane. The nictitating membrane sweeps across the eye diagonally or horizontally. In humans, the plica semilunaris (or semilunar fold) is thought to be the vestigial remnant of the nictitating membrane.
It has been suggested that eyelids evolved as a way to remove debris from the eyes. Given that fish have a constant stream of water flowing over their eyes, it is not surprising that they do not have eyelids or need specialized membranes to perform this function.
Double eyelid
A double eyelid is a type of eyelid where a crease exists. In contrast, a single eyelid has no crease. There is a wide variation in the location of the crease, particularly in the Asian double eyelid. Further discussion and pictures of the variations in Asian double eyelids can be found here. A double eyelid can be created in a person with a single eyelid by Asian blepharoplasty or "Double Eyelid Surgery" through a variety of methods that depend on the anatomy of the eyelid and the desired appearance.[1]See also
Disorders
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Eyelid affected by Stye.
- Blepharospasm
- Cellulitis
- Chalazion
- Dermatochalasis
- Ectropion
- Entropion
- Hay-Wells syndrome
- Ptosis
- Stye (Hordeolum)
Surgeries
Additional images
) Eye makeup | Bloodvessels of the eyelids, front view. | ) Horizontal section through the eye of an eighteen days’ embryo rabbit. X 30. | Sagittal section of right orbital cavity. |
) Sagittal section through the upper eyelid. | The tarsi and their ligaments. Right eye; front view. | The lacrimal apparatus. Right side. |
References
External links
Accessory organs of the eye | |
|---|---|
| General | Eyebrow - Eyelid - Canthus - Eyelash - Ciliary glands - Orbital septum - Plica semilunaris - Meibomian gland |
| Lacrimal apparatus | Lacrimal lake - Lacrimal gland - Lacrimal canaliculi - Lacrimal punctum - Lacrimal papilla - Nasolacrimal duct |
Latin}}}
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Arteries are muscular blood vessels that carry blood away from the heart.[1] All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.
The circulatory system is extremely important for sustaining life.
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The circulatory system is extremely important for sustaining life.
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The lacrimal artery arises close to the optic foramen, and is one of the largest branches derived from the ophthalmic artery: not infrequently it is given off before the artery enters the orbit.
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The medial palpebral arteries (internal palpebral arteries) are arteries of the head. They are two in number, superior and inferior, arise from the ophthalmic, opposite the pulley of the Obliquus superior.
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The medial palpebral arteries (internal palpebral arteries) are arteries of the head. They are two in number, superior and inferior, arise from the ophthalmic, opposite the pulley of the Obliquus superior.
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A nerve is an enclosed, cable-like bundle of axons (the long, slender projection of a neuron). Neurons are sometimes called nerve cells, though this term is technically imprecise since many neurons do not form nerves, and nerves also include the glial cells that
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The infratrochlear nerve is given off from the nasociliary just before it enters the anterior ethmoidal foramen.
It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.
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It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.
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The supraorbital nerve is a terminal branch of the frontal nerve.
It passes through the supraorbital foramen, and gives off, in this situation, palpebral filaments to the upper eyelid.
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It passes through the supraorbital foramen, and gives off, in this situation, palpebral filaments to the upper eyelid.
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The lacrimal nerve is the smallest of the three branches of the ophthalmic.
It sometimes receives a filament from the trochlear nerve, but this is possibly derived from the branch which goes from the ophthalmic to the trochlear nerve.
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It sometimes receives a filament from the trochlear nerve, but this is possibly derived from the branch which goes from the ophthalmic to the trochlear nerve.
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The infratrochlear nerve is given off from the nasociliary just before it enters the anterior ethmoidal foramen.
It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.
..... Click the link for more information.
It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.
..... Click the link for more information.
infraorbital nerve. This nerve innervates the lower eyelid, upper lip, and part of the vestibule and exits the infraorbital foramen of the maxilla.
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See also
- infraorbital artery
- external nasal nerve
Additional images
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Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed
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Eyes are organs of vision that detect light. Different kinds of light-sensitive organs are found in a variety of organisms. The simplest eyes do nothing but detect whether the surroundings are light or dark, while more complex eyes can distinguish shapes and colors.
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The prepuce[pronunciation needed]
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The labia minora (singular: labium minus) are two small longitudinal cutaneous folds, situated between the labia majora, and extending from the clitoris obliquely downward, lateralward, and backward for about 4 cm.
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The levator palpebrae superioris (or levator muscle of upper eyelid) is the muscle in the orbit that elevates the superior (upper) eyelid.
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Structure
The levator palpebrae superioris originates on the lesser wing of the sphenoid bone, just above the optic foramen...... Click the link for more information.
An eyelash or simply lash is one of the hairs that grow at the edge of the eyelid. Eyelashes protect the eye from debris and perform some of the same function as whiskers do on a cat or a mouse in the sense that they are sensitive to being touched, thus providing a warning
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Skin layers: epidermis, dermis, and subcutis, showing a hair follicle, sweat gland & sebaceous gland.]] In zootomy and dermatology, skin is the largest organ of the integumentary system made up of multiple layers of epithelial tissues that guard underlying muscles and organs.
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subcutis is the layer of tissue directly underlying the cutis. It is mainly composed of adipose tissue. Its physiological function includes insulation and storage of nutrients.
Subcutaneous injections are given by injecting a fluid or a solid pellet into the subcutis.
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Subcutaneous injections are given by injecting a fluid or a solid pellet into the subcutis.
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The orbicularis oculi is a muscle in the face that closes the eyelids. It arises from the nasal part of the frontal bone, from the frontal process of the maxilla in front of the lacrimal groove, and from the anterior surface and borders of a short fibrous band, the medial
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The orbital septum (palpebral ligament) is a membranous sheet that acts as the anterior boundary of the orbit. It extends from the orbital rims to the eyelids.
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The conjunctiva is a membrane that covers the sclera (white part of the eye) and lines the inside of the eyelids.
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Function
It helps lubricate the eye by producing mucus and tears, although a smaller volume of tears than the lacrimal gland...... Click the link for more information.
The infratrochlear nerve is given off from the nasociliary just before it enters the anterior ethmoidal foramen.
It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.
..... Click the link for more information.
It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.
..... Click the link for more information.
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Supraorbital can refer to:
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- Supraorbital artery
- Supraorbital foramen
- Supraorbital gland
- Supraorbital nerve
- Supraorbital ridge
- Supraorbital vein
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The lacrimal nerve is the smallest of the three branches of the ophthalmic.
It sometimes receives a filament from the trochlear nerve, but this is possibly derived from the branch which goes from the ophthalmic to the trochlear nerve.
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It sometimes receives a filament from the trochlear nerve, but this is possibly derived from the branch which goes from the ophthalmic to the trochlear nerve.
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The trigeminal nerve (the fifth cranial nerve, also called the fifth nerve or simply V) is responsible for sensation in the face. It is similar to the spinal nerves C2–S5, which are responsible for sensation in the rest of the body.
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The infratrochlear nerve is given off from the nasociliary just before it enters the anterior ethmoidal foramen.
It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.
..... Click the link for more information.
It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.
..... Click the link for more information.
infraorbital nerve. This nerve innervates the lower eyelid, upper lip, and part of the vestibule and exits the infraorbital foramen of the maxilla.
..... Click the link for more information.
See also
- infraorbital artery
- external nasal nerve
Additional images
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