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Palpebral
An eyelid ( ) is a thin fold of skin that covers and protects an eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. "Palpebral" (and "blepharal") means relating to the eyelids. Its key function is to regularly spread the tears and other secretions on the eye surface to keep it moist, since the cornea must be continuously moist. They keep the eyes from drying out when asleep. Moreover, the blink reflex protects the eye from foreign bodies. A set of specialized hairs known as Eyelash, lashes grow from the upper and lower eyelid margins to further protect the eye from dust and debris. The appearance of the human upper eyelid often varies between different populations. The prevalence of an epicanthic fold covering the inner corner of the eye account for the majority of East Asian and Southeast Asian populations, and is also found in varying degrees among other pop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbicularis Oculi Muscle
The orbicularis oculi is a Sphincter, sphincter-like 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 palpebral ligament. From this origin, the fibers are directed laterally, forming a broad and thin layer, which occupies the eyelids or palpebræ, surrounds the circumference of the orbit, and spreads over the temple, and downward on the cheek. Structure There are at least 3 clearly defined sections of the orbicularis muscle. However, it is not clear whether the lacrimal section is a separate section, or whether it is just an extension of the preseptal and pretarsal sections. Orbital orbicularis The orbital portion is thicker and of a reddish color; its fibers form a complete ellipse without interruption at the lateral palpebral commissure; the upper fibers of this portion blend with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levator Palpebrae Superioris Muscle
The levator palpebrae superioris () is the muscle in the orbit that elevates the upper eyelid. Structure The levator palpebrae superioris originates from inferior surface of the lesser wing of the sphenoid bone, just above the optic foramen. It broadens and decreases in thickness (becomes thinner) and becomes the levator aponeurosis. This portion inserts on the skin of the upper eyelid, as well as the superior tarsal plate. It is a skeletal muscle. The superior tarsal muscle, a smooth muscle, is attached to the levator palpebrae superioris, and inserts on the superior tarsal plate as well. Blood supply The levator palebrae superioris receives its blood supply from branches of the ophthalmic artery, specifically, muscular branches and the supraorbital artery. Blood is drained into the superior ophthalmic vein. Nerve supply The levator palpebrae superioris receives motor innervation from the superior division of the oculomotor nerve. The smooth muscle that originates from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjunctiva
In the anatomy of the eye, the conjunctiva (: conjunctivae) is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium and stratified cuboidal epithelium (depending on the zone). The conjunctiva is highly Angiogenesis, vascularised, with many microvessels easily accessible for imaging studies. Structure The conjunctiva is typically divided into three parts: Blood supply Blood to the bulbar conjunctiva is primarily derived from the ophthalmic artery. The blood supply to the palpebral conjunctiva (the eyelid) is derived from the external carotid artery. However, the circulations of the bulbar conjunctiva and palpebral conjunctiva are linked, so both bulbar conjunctival and palpebral conjunctival vessels are supplied by both the ophthalmic artery and the external carotid artery, to varying extents. Nerve supply Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Septum
In anatomy, the orbital septum (palpebral fascia) is a membranous sheet that acts as the anterior (frontal) boundary of the orbit. It extends from the orbital rims to the eyelids. It forms the fibrous portion of the eyelids. Structure In the upper eyelid, the orbital septum blends with the tendon of the levator palpebrae superioris, and in the lower eyelid with the tarsal plate. When the eyes are closed, the whole orbital opening is covered by the septum and tarsi. Medially it is thin, and, becoming separated from the medial palpebral ligament, attaches to the lacrimal bone at its posterior crest. The medial ligament and its much weaker lateral counterpart, attached to the septum and orbit, keep the lids stable as the eye moves. The septum is perforated by the vessels and nerves which pass from the orbital cavity to the face and scalp. Clinical significance Orbital septum supports the orbital contents located posterior to it, especially orbital fat. The septum can be w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Palpebral Arteries
The lateral palpebral arteries are the two large branches of those terminal branches of the lacrimal gland The lacrimal glands are paired exocrine glands, one for each eye, found in most terrestrial vertebrates and some marine mammals, that secrete the aqueous layer of the tear film. In humans, they are situated in the upper lateral region of each o ... that supply the eyelid, with one lateral palpebral artery supplying one eyelid or the other. They pass medial-ward within the eyelid. They anastomose with medial palpebral arteries to form an arterial circle. See also * Medial palpebral arteries References Arteries of the head and neck {{circulatory-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anastomoses
An anastomosis (, : anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection may be normal (such as the foramen ovale (heart), foramen ovale in a fetus' heart) or abnormal (such as the atrial septal defect#Patent foramen ovale, patent foramen ovale in an adult's heart); it may be acquired (such as an arteriovenous fistula) or innate (such as the arteriovenous shunt of a metarteriole); and it may be natural (such as the aforementioned examples) or artificial (such as a surgical anastomosis). The reestablishment of an anastomosis that had become blocked is called a reanastomosis. Anastomoses that are abnormal, whether congenital disorder, congenital or acquired, are often called fistulas. The term is used in medicine, biology, mycology, geology, and geography. Etymology Anastomosis: medical or Modern Latin, from Greek á¼€ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infraorbital Nerve
The infraorbital nerve is a branch of the maxillary nerve (itself a branch of the trigeminal nerve (CN V)). It arises in the pterygopalatine fossa. It passes through the inferior orbital fissure to enter the orbit. It travels through the orbit, then enters and traverses the infraorbital canal, exiting the canal at the infraorbital foramen to reach the face. It provides sensory innervation to the skin and mucous membranes around the middle of the face. Structure Origin The infraorbital nerve is a branch of the maxillary nerve (CN V2), itself a branch of the trigeminal nerve (CN V); it may be considered as the terminal branch of the maxillary nerve. It arises from the maxillary nerve in the pterygopalatine fossa. Course It travels through the inferior orbital fissure to enter the orbit. It runs anteriorly along the floor of the orbit in the infraorbital groove to the infraorbital canal of the maxilla. Within the infraorbital canal it has three branches, the posterior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigeminal Nerve
In neuroanatomy, the trigeminal nerve (literal translation, lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for Sense, sensation in the face and motor functions such as biting and chewing; it is the most complex of the cranial nerves. Its name (''trigeminal'', ) derives from each of the two nerves (one on each side of the pons) having three major branches: the ophthalmic nerve (V), the maxillary nerve (V), and the mandibular nerve (V). The ophthalmic and maxillary nerves are purely sensory, whereas the mandibular nerve supplies motor as well as sensory (or "cutaneous") functions. Adding to the complexity of this nerve is that Autonomic nervous system, autonomic nerve fibers as well as special sensory fibers (taste) are contained within it. The motor division of the trigeminal nerve derives from the Basal plate (neural tube), basal plate of the embryonic pons, and the sensory division originates in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Nerve
The lacrimal nerve is the smallest of the three main branches of the ophthalmic nerve (CN V1) (itself a branch of the trigeminal nerve (CN V)). It enters the orbit outside the common tendinous ring and passes forward along the side wall of the orbit. It provides sensory innervation to the skin and both surfaces of conjunctiva at the lateral portion of the upper eyelid. It also receives a parasympathetic secretomotor communicating branch for the lacrimal gland which it conveys to the gland. Structure Origin The lacrimal nerve branches from the ophthalmic nerve immediately before traveling through the superior orbital fissure to enter the orbit. At the superior portion of the lateral wall of the orbit, it also receives a secretomotor communicating parasympathetic branch from the zygomaticotemporal nerve for the lacrimal gland. Course It enters the orbit through the superior orbital fissure outside (lateral to) the common tendinous ring, coursing lateral to the front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supraorbital Nerve
The supraorbital nerve is one of two terminal branches - the other being the supratrochlear nerve - of the frontal nerve (itself a branch of the ophthalmic nerve (CN V1)). It exits the orbit via the supraorbital foramen/notch before splitting into a medial branch and a lateral branch. It innervates the skin of the forehead, upper eyelid, and the root of the nose. Structure Origin The supraorbital nerve branches from the frontal nerve midway between the base and apex of the orbit. Course It travels anteriorly superior to the levator palpebrae superioris muscle. It exits the orbit through the supraorbital foramen/notch in the superior margin orbit, exiting it lateral to the supratrochlear nerve. It then ascends onto the forehead deep to the corrugator supercilii muscle and frontalis muscles. Fate It divides into a medial branch and lateral branch - usually after emerging from the orbit, but sometimes already within the orbit. Distribution The supraorbital nerv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supratrochlear
The supratrochlear nerve is a branch of the frontal nerve, itself a branch of the ophthalmic nerve (CN V1) from the trigeminal nerve (CN V). It provides sensory innervation to the skin of the forehead and the upper eyelid. Structure Origin The supratrochlear nerve is the smaller of the two terminal branches of the frontal nerve (the other being the supraorbital nerve). It arises midway between the base and apex of the orbit where the frontal nerve splits into said terminal branches. Course The supratrochlear nerve passes medially above the trochlea of the superior oblique muscle. It then travels anteriorly above the levator palpebrae superioris muscle. It exits the orbit through the supratrochlear notch or foramen. It then ascends onto the forehead beneath the corrugator supercilii muscle and frontalis muscle. It finally divides into sensory branches. The supratrochlear nerve travels with the supratrochlear artery, a branch of the ophthalmic artery. Branches Before ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infratrochlear
The infratrochlear nerve is a branch of the nasociliary nerve (itself a branch of the ophthalmic nerve (CN V1)) in the orbit. It exits the orbit inferior to the trochlea of superior oblique. It provides sensory innervation to structures of the orbit and skin of adjacent structures. Structure The nasociliary nerve terminates by bifurcating into the infratrochlear and the anterior ethmoidal nerves. The infratrochlear nerve travels anteriorly in the orbit along the upper border of the medial rectus muscle and underneath the trochlea of the superior oblique muscle. It exits the orbit medially and divides into small sensory branches. Distribution The infratrochlear nerve provides sensory innervation to the skin of the eyelids, the conjunctiva, lacrimal sac, lacrimal caruncle, and the side of the nose superior to the medial canthus. Communications The infratrochlear nerve receives a descending communicating branch from the supratrochlear nerve The supratrochlear nerve is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
