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Medial Palpebral Ligament
The medial palpebral ligament (medial canthal tendon) is a ligament of the face. It attaches to the Frontal process of maxilla, frontal process of the maxilla, the lacrimal groove, and the Tarsus (eyelids), tarsus of each eyelid. It has a superficial (anterior) and a deep (posterior) layer, with many surrounding attachments. It connects the Canthus, medial canthus of each eyelid to the medial part of the Orbit (anatomy), orbit. It is a useful point of fixation during eyelid reconstructive surgery. Structure The anterior attachment of the medial palpebral ligament is to the frontal process of maxilla, frontal process of the maxilla in front of the lacrimal groove (near the nasal bone and the frontal bone), and its posterior attachment is the lacrimal bone. Crossing the lacrimal sac, it divides into two parts, upper and lower, each attached to the medial end of the corresponding tarsus (eyelids), tarsus of each eyelid. As the ligament crosses the lacrimal sac, a strong aponeuroti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tarsus (eyelids)
The tarsi (tarsal plates) are two comparatively thick, elongated plates of dense connective tissue, about in length for the upper eyelid and 5 mm for the lower eyelid; one is found in each eyelid, and contributes to its form and support. They are located directly above the lid margins. The tarsus has a lower and upper part making up the palpebrae. Superior The ''superior tarsus'' (''tarsus superior''; superior tarsal plate), the larger, is of a semilunar form, about in breadth at the center, and gradually narrowing toward its extremities. It is adjoined by the superior tarsal muscle. To the anterior surface of this plate the aponeurosis of the levator palpebræ superioris is attached. Inferior The ''inferior tarsus'' (''tarsus inferior''; inferior tarsal plate) is smaller, is thin, is elliptical in form, and has a vertical diameter of about . The free or ciliary margins of these plates are thick and straight. Relations The attached or orbital margins are connected to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Sac
The lacrimal sac or lachrymal sac is the upper dilated end of the nasolacrimal duct, and is lodged in a deep groove formed by the lacrimal bone and frontal process of the maxilla. It connects the lacrimal canaliculi, which drain tears from the eye's surface, and the nasolacrimal duct, which conveys this fluid into the nasal cavity. Lacrimal sac occlusion leads to dacryocystitis. Structure It is oval in form and measures from 12 to 15 mm. in length; its upper end is closed and rounded; its lower is continued into the nasolacrimal duct. Its superficial surface is covered by a fibrous expansion derived from the medial palpebral ligament, and its deep surface is crossed by the lacrimal part of the orbicularis oculi, which is attached to the crest on the lacrimal bone. Histology Like the nasolacrimal duct, the sac is lined by stratified columnar epithelium with mucus-secreting goblet cells, with surrounding connective tissue. The Lacrimal Sac also drains the eye of debris and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbicularis Oculi Muscle
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 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 frontalis and corrugator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbicularis Oculi Muscle
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 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 frontalis and corrugator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability to withstand significant amounts of tension. Tendons are similar to ligaments; both are made of collagen. Ligaments connect one bone to another, while tendons connect muscle to bone. Structure Histologically, tendons consist of dense regular connective tissue. The main cellular component of tendons are specialized fibroblasts called tendon cells (tenocytes). Tenocytes synthesize the extracellular matrix of tendons, abundant in densely packed collagen fibers. The collagen fibers are parallel to each other and organized into tendon fascicles. Individual fascicles are bound by the endotendineum, which is a delicate loose connective tissue containing thin collagen fibrils and elastic fibres. Groups of fascicles are bounded by the epitenon, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blinking
Blinking is a bodily function; it is a semi-autonomic rapid closing of the eyelid. A single blink is determined by the forceful closing of the eyelid or inactivation of the levator palpebrae superioris and the activation of the palpebral portion of the orbicularis oculi, not the full open and close. It is an essential function of the eye that helps spread tears across and remove irritants from the surface of the cornea and conjunctiva. Blinking may have other functions since it occurs more often than necessary just to keep the eye lubricated. Researchers think blinking may help with disengagement of attention; following blink onset, cortical activity decreases in the dorsal network and increases in the default-mode network, associated with internal processing. Blink speed can be affected by elements such as fatigue, eye injury, medication, and disease. The blinking rate is determined by the "blinking center", but it can also be affected by external stimulus. Some animals, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ScienceDirect
ScienceDirect is a website which provides access to a large bibliographic database of scientific and medical publications of the Dutch publisher Elsevier. It hosts over 18 million pieces of content from more than 4,000 academic journals and 30,000 e-books of this publisher. The access to the full-text requires subscription, while the bibliographic metadata is free to read. ScienceDirect is operated by Elsevier. It was launched in March 1997. Usage The journals are grouped into four main sections: ''Physical Sciences and Engineering'', ''Life Sciences'', ''Health Sciences'', and ''Social Sciences and Humanities''. Article abstracts are freely available, and access to their full texts (in PDF and, for newer publications, also HTML) generally requires a subscription or pay-per-view purchase unless the content is freely available in open access. Subscriptions to the overall offering hosted on ScienceDirect, rather than to specific titles it carries, are usually acquired through a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Nose
The human nose is the most protruding part of the face. It bears the nostrils and is the first organ of the respiratory system. It is also the principal organ in the olfactory system. The shape of the nose is determined by the nasal bones and the nasal cartilages, including the nasal septum which separates the nostrils and divides the nasal cavity into two. On average the nose of a male is larger than that of a female. The nose has an important function in breathing. The nasal mucosa lining the nasal cavity and the paranasal sinuses carries out the necessary conditioning of inhaled air by warming and moistening it. Nasal conchae, shell-like bones in the walls of the cavities, play a major part in this process. Filtering of the air by nasal hair in the nostrils prevents large particles from entering the lungs. Sneezing is a reflex to expel unwanted particles from the nose that irritate the mucosal lining. Sneezing can transmit infections, because aerosols are created in w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buccal Branches Of The Facial Nerve
The buccal branches of the facial nerve (infraorbital branches), are of larger size than the rest of the branches, pass horizontally forward to be distributed below the orbit and around the mouth. Branches The ''superficial branches'' run beneath the skin and above the superficial muscles of the face, which they supply: some are distributed to the procerus, joining at the medial angle of the orbit with the infratrochlear and nasociliary branches of the ophthalmic. The ''deep branches'' pass beneath the zygomaticus and the quadratus labii superioris, supplying them and forming an infraorbital plexus with the infraorbital branch of the maxillary nerve. These branches also supply the small muscles of the nose. The ''lower deep branches'' supply the buccinator and orbicularis oris, and join with filaments of the buccinator branch of the mandibular nerve. Muscles of facial expression The facial nerve innervates the muscles of facial expression. The buccal branch supplies these mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facial Nerve
The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue. The nerve typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen. It arises from the brainstem from an area posterior to the cranial nerve VI (abducens nerve) and anterior to cranial nerve VIII (vestibulocochlear nerve). The facial nerve also supplies preganglionic parasympathetic fibers to several head and neck ganglia. The facial and intermediate nerves can be collectively referred to as the nervus intermediofacialis. The path of the facial nerve can be divided into six segments: # intracranial (cisternal) segment # meatal (canalicular) segment (within the internal auditory canal) # labyrinthine segment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Palpebral Arteries
The medial palpebral arteries (internal palpebral arteries) are arteries of the head that contribute arterial blood supply to the eyelids. They are derived from the ophthalmic artery; a single medial palpebral artery issues from the ophthalmic artery before splitting into a superior and an inferior medial palpebral artery, each supplying one eyelid. Anatomy Origin A single medial palpebral artery issues from the ophthalmic artery before bifurcating into a superior and an inferior medial palpebral artery. The origin occurs near the trochlea of the superior oblique muscle. Course The medial palpebral arteries leave the orbit to encircle the eyelids near their free margins, forming a superior and an inferior arch, which lie between the orbicularis oculi and the tarsi. Anastomoses The superior medial palpebral artery anastomoses (at lateral angle of the orbit) with the upper lateral palpebral artery, and the zygomaticoorbital branch of the temporal artery. The inferior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newton (unit)
The newton (symbol: N) is the unit of force in the International System of Units (SI). It is defined as 1 kg⋅m/s, the force which gives a mass of 1 kilogram an acceleration of 1 metre per second per second. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion. Definition A newton is defined as 1 kg⋅m/s (it is a derived unit which is defined in terms of the SI base units). One newton is therefore the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in the direction of the applied force. The units "metre per second squared" can be understood as measuring a rate of change in velocity per unit of time, i.e. an increase in velocity by 1 metre per second every second. In 1946, Conférence Générale des Poids et Mesures (CGPM) Resolution 2 standardized the unit of force in the MKS system of units to be the amount needed to accelerate 1 kilogram of mass at the rate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
