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Abducens Nerve
The abducens nerve or abducent nerve, also known as the sixth cranial nerve, cranial nerve VI, or simply CN VI, is a cranial nerve in humans and various other animals that controls the movement of the lateral rectus muscle, one of the extraocular muscles responsible for outward gaze. It is a somatic efferent nerve. Structure Nucleus The abducens nucleus is located in the pons, on the floor of the fourth ventricle, at the level of the facial colliculus. Axons from the facial nerve loop around the abducens nucleus, creating a slight bulge (the facial colliculus) that is visible on the dorsal surface of the floor of the fourth ventricle. The abducens nucleus is close to the midline, like the other motor nuclei that control eye movements (the oculomotor and trochlear nuclei). Motor axons leaving the abducens nucleus run ventrally and caudally through the pons. They pass lateral to the corticospinal tract (which runs longitudinally through the pons at this level) before exiting t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Rectus Muscle
Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral consonant, an l-like consonant in which air flows along the sides of the tongue **Lateral release (phonetics), the release of a plosive consonant into a lateral consonant Other uses *''Lateral'', journal of the Cultural Studies Association *Lateral canal, a canal built beside another stream *Lateral hiring, recruiting that targets employees of another organization *Lateral mark, a sea mark used in maritime pilotage to indicate the edge of a channel * Lateral stability of aircraft during flight *Lateral pass, a type of pass in American and Canadian football *Lateral support (other), various meanings *Lateral thinking, the solution of problems through an indirect and creative approach *Lateral number, a proposed alternate term for imagi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medullary Pyramids (brainstem)
In neuroanatomy, the medullary pyramids are paired white matter structures of the brainstem's medulla oblongata that contain motor fibers of the corticospinal and corticobulbar tracts – known together as the pyramidal tracts. The lower limit of the pyramids is marked when the fibers cross (decussate). Structure The ventral portion of the medulla oblongata contains the medullary pyramids. These two ridge-like structures travel along the length of the medulla oblongata and are bordered medially by the anterior median fissure. They each have an anterolateral sulcus along their lateral borders, where the hypoglossal nerve emerges from. Also at the side of each pyramid there is a pronounced bulge known as an olive. Fibers of the posterior column, which transmit sensory and proprioceptive information, are located behind the pyramids on the medulla oblongata. The medullary pyramids contain motor fibers that are known as the corticobulbar and corticospinal tracts. The corticospina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Tendinous Ring
The common tendinous ring, also known as the annulus of Zinn, or annular tendon, is a ring of fibrous tissue surrounding the optic nerve at its entrance at the apex of the orbit. It is the common origin of the four recti muscles of the group of extraocular muscles. It can be used to divide the regions of the superior orbital fissure. The arteries surrounding the optic nerve form a vascular structure known as the circle of Zinn-Haller, or sometimes as the ''circle of Zinn''. The following structures pass through the tendinous ring (superior to inferior): * Superior division of the oculomotor nerve (CNIII) * Nasociliary nerve (branch of ophthalmic nerve) * Inferior division of the oculomotor nerve (CNIII) * Abducens nerve (CNVI) * Optic nerve Parts The common tendinous ring spans the superior orbital fissure and can be described as having two parts – an inferior tendon which gives origin to the inferior rectus muscle, and to part of the lateral rectus muscle; and a superior t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Orbital Fissure
The superior orbital fissure is a foramen or cleft of the skull between the lesser and greater wings of the sphenoid bone. It gives passage to multiple structures, including the oculomotor nerve, trochlear nerve, ophthalmic nerve, abducens nerve, ophthalmic veins, and sympathetic fibres from the cavernous plexus. Structure The superior orbital fissure is usually 22 mm wide in adults, and is much larger medially. Its boundaries are formed by the (caudal surface of the) lesser wing of the sphenoid bone, and (medial border of the) greater wing of the sphenoid bone. Contents The superior orbital fissure is traversed by the following structures: * (superior and inferior divisions of the) oculomotor nerve (CN III) * trochlear nerve (CN IV) * lacrimal, frontal, and nasociliary branches of ophthalmic nerve (CN V1) * abducens nerve (CN VI) * superior ophthalmic vein and superior division of the inferior ophthalmic vein * sympathetic fibres from the cavernous nerve pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Carotid Artery
The internal carotid artery (Latin: arteria carotis interna) is an artery in the neck which supplies the anterior circulation of the brain. In human anatomy, the internal and external carotids arise from the common carotid arteries, where these bifurcate at cervical vertebrae C3 or C4. The internal carotid artery supplies the brain, including the eyes, while the external carotid nourishes other portions of the head, such as the face, scalp, skull, and meninges. Classification Terminologia Anatomica in 1998 subdivided the artery into four parts: "cervical", "petrous", "cavernous", and "cerebral". However, in clinical settings, the classification system of the internal carotid artery usually follows the 1996 recommendations by Bouthillier, describing seven anatomical segments of the internal carotid artery, each with a corresponding alphanumeric identifier—C1 cervical, C2 petrous, C3 lacerum, C4 cavernous, C5 clinoid, C6 ophthalmic, and C7 communicating. The Bouthillier nomenclat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavernous Sinus
The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica. Structure The cavernous sinus is one of the dural venous sinuses of the head. It is a network of veins that sit in a cavity. It sits on both sides of the sphenoidal bone and pituitary gland, approximately 1 × 2 cm in size in an adult. The carotid siphon of the internal carotid artery, and cranial nerves III, IV, V (branches V1 and V2) and VI all pass through this blood filled space. Both sides of cavernous sinus is connected to each other via intercavernous sinuses. The cavernous sinus lies in between the inner and outer layers of dura mater. Nearby structures * Above: optic tract, optic chiasma, internal carotid artery. * Inferiorly: foramen lacerum, and the junction of the body and greater wing of sphenoid bone. * Medially: pituitary gla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petrous Part Of The Temporal Bone
The petrous part of the temporal bone is pyramid-shaped and is wedged in at the base of the skull between the sphenoid and occipital bones. Directed medially, forward, and a little upward, it presents a base, an apex, three surfaces, and three angles, and houses in its interior, the components of the inner ear. The petrous portion is among the most basal elements of the skull and forms part of the endocranium. Petrous comes from the Latin word ''petrosus'', meaning "stone-like, hard". It is one of the densest bones in the body. The petrous bone is important for studies of ancient DNA from skeletal remains, as it tends to contain extremely well-preserved DNA. Base The base is fused with the internal surfaces of the squamous and mastoid parts. Apex The apex, which is rough and uneven, is received into the angular interval between the posterior border of the great wing of the sphenoid bone and the basilar part of the occipital bone; it presents the anterior or internal openin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operative Neurosurgery
''Neurosurgery'' is a monthly peer reviewed medical journal of neurosurgery and the official journal of the Congress of Neurological Surgeons. It is published by Oxford University Press. The journal publishes original research, reviews, and editorials. History Discussion about a new specialist journal began in 1973 at a Southern Neurosurgical Society meeting, held in New Orleans, Louisiana. For the next 3 years negotiations took place to either purchase an existing journal or start a new one. In July 1976, during a meeting of the Executive Committee of the Congress of Neurological Surgeons, the decision to begin a new publication was made at the recommendation of the Congress' Publication Committee. President Robert G. Ojemann made the announcement of its launch at the 26th Annual Meeting of the Congress of Neurological Surgeons on October 27, 1976 and the inaugural issue of ''Neurosurgery'' was published in July 1977 as a bimonthly publication. The journal shifted to monthly pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Neurosurgery
The ''Journal of Neurosurgery'' is a monthly peer-reviewed medical journal covering all aspects of neurosurgery. It is published by the American Association of Neurological Surgeons and the editor-in-chief is James Rutka. It was established in 1944, with Louise Eisenhardt Louise Eisenhardt (17 July 1891 – 22 January 1967) was one of the first neuropathologists and was considered leading world expert on tumor diagnosis. She became the first woman president of the American Association of Neurological Surgeons. ... as founding editor. Originally published bimonthly, it switched to a monthly schedule in 1962. All content is freely available online after 12 months, until it is 10 years old. Editors-in-chief The following persons have been editors-in-chief of the journal: * James Rutka (2013–present) * John A. Jane (1992–2013) * Thoralf Sundt, Jr. (1989–1992) * William Collins Jr. (1985–1989) * Henry Schwartz (1975–1985) * Henry Heyl (1965–1975) * Louise Eisenhar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorello's Canal
Dorello's canal is the bow-shaped bony enclosure at the tip of the temporal bone. It surrounds the abducens nerve (CN VI) and the inferior petrosal sinus as the two structures merge with the cavernous sinus. Structure Dorello's canal is a bow-shaped bony enclosure at the tip of the petrous part of the temporal bone. It is fairly short. Dura mater forms a sleeve within Dorello's canal, forming an outer wall. There may also be arachnoid mater. This contains the abducens nerve (VI) and the inferior petrosal sinus. The petrosphenoidal ligament (Gruber's ligament, or petroclinoidal ligament) forms the posteromedial wall of Dorello's canal. Function Dorello's canal allows for passage of the abducens nerve (CN VI) and the inferior petrosal sinus as they travel to merge with the cavernous sinus. Clinical significance Dorello's canal can entrap the abducens nerve (CN VI) after cranial trauma. History Dorello's canal is named after the Italian anatomist Primo Dorello, who prove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dura Mater
In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. The other two meningeal layers are the arachnoid mater and the pia mater. It envelops the arachnoid mater, which is responsible for keeping in the cerebrospinal fluid. It is derived primarily from the neural crest cell population, with postnatal contributions of the paraxial mesoderm. Structure The dura mater has several functions and layers. The dura mater is a membrane that envelops the arachnoid mater. It surrounds and supports the dural sinuses (also called dural venous sinuses, cerebral sinuses, or cranial sinuses) and carries blood from the brain toward the heart. Cranial dura mater has two layers called ''lamellae'', a superficial layer (also called the periosteal layer), which serves as the skull's inner periosteum, called the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clivus (anatomy)
The clivus (, Latin for "slope"), or Blumenbach clivus, is a bony part of the cranium The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ... at the base of the skull. It is a shallow depression behind the dorsum sellae of the sphenoid bone. It slopes gradually to the anterior part of the basilar occipital bone at its junction with the sphenoid bone. It extends to the foramen magnum. It is related to the pons and the abducens nerve (CN VI). Structure The clivus is a shallow depression behind the dorsum sellae of the sphenoid bone. It slopes gradually to the anterior part of the basilar occipital bone at its junction with the sphenoid bone. Synchondrosis of these two bones forms the clivus. The clivus extends inferiorly to the foramen magnum. On axial planes, it sits just posterior to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
