Articles

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3,363 results found
Article

Spiral glenohumeral ligament

The spiral glenohumeral ligament, also termed fasciculus obliquus, ligamentum glenohumerale spirale and spiral GHL, is a focal thickening of the glenohumeral joint capsule, akin to the other glenohumeral ligaments, yet it is not widely recognized 1.  Gross anatomy The spiral glenohumeral ligam...
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Appendix

The appendix or vermiform appendix (plural: appendices) is a blind muscular tube arising from the cecum, the first part of the large bowel. Gross anatomy The appendix arises from the posteromedial surface of the cecum, approximately 2-3 cm inferior to the ileocecal valve, where the three longi...
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Bovine arch

Bovine arch is the most common variant of the aortic arch and occurs when the brachiocephalic (innominate) artery shares a common origin with the left common carotid artery.  Epidemiology A bovine arch is present in ~15% (range 8-27%) of the population and is more common in individuals of Afri...
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Posterior tibial artery

The posterior tibial artery (PTA) is one of the 2 branches of the tibioperoneal trunk in the lower leg and provides oxygenated blood to the posterior compartments of the leg and plantar surface of the foot. It is accompanied by the posterior tibial vein, along its course. Summary origin: tibio...
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Persistent hypophyseal canal

Persistent hypophyseal canal, also known as the craniopharyngeal canal when larger than 1.5 mm in diameter, is a rare congenital defect characterized by communication through the central skull base between the nasopharynx and the pituitary fossa.  Terminology There are a number of terms that r...
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Lumbosacral trunk

The lumbosacral trunk is the distal trunk of the lumbar plexus arising from the anterior rami of the L4 and L5 nerve roots which contributes to the sacral plexus. Gross anatomy Origin It arises from anterior rami of L4-L5 roots of the lumbar plexus. Course emerges over the medial border of ...
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Infrahyoid muscles

The infrahyoid muscles or strap muscles are a group of four paired muscles in the anterior neck below the hyoid bone, within the muscular triangle. They are responsible for depressing the hyoid during swallowing. These muscles can be remembered by the mnemonic "TOSS". They can be difficult to d...
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Pontine arteries

The pontine branches are the small arterial branches of the basilar artery that supply the pons and structures adjacent to the pons. There are usually 3-5 paired arterial branches which are located in the mid-basilar region between the anterior inferior cerebellar artery and the superior cerebe...
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Wilbrand knee (optic radiation)

The Wilbrand knee refers to a small anterior loop of axons from the medial retina passing a short distance into the contralateral prechiasmatic optic nerve after decussating in the optic chiasm. It is said to account for the occurrence of the junctional scotoma caused by lesions at the junction ...
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Ligamentum teres of the hip

The ligamentum teres, also known as the ligamentum capitis femoris or round ligament of the hip, is an intra-articular ligament within the medial hip joint. Gross anatomy The ligament passes from the transverse ligament and acetabular notch of the acetabulum to the femoral head where it insert...
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Agger nasi cells

Agger nasi air cells are the most anterior ethmoidal air cells lying anterolateral and inferior to the frontal recess and anterior and above the attachment of the middle turbinate. They are located within the lacrimal bone and therefore have as lateral relations the orbit, the lacrimal sac and t...
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Autonomic nervous system

The autonomic nervous system (ANS) is a subdivision of the peripheral nervous system. The autonomic system provides innervation of the involuntary muscles, i.e. myocardium and smooth muscle, and glands, through which fine control of homeostasis is maintained. The afferent innervation of the aut...
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Parasympathetic nervous system

The parasympathetic nervous system (PaNS/PNS), mediated by the head and neck ganglia and pelvic splanchnic nerves, is a major division of the autonomic nervous system. It is composed of general visceral afferent and efferent axons that allow for involuntary control of bodily functions via severa...
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Sympathetic nervous system

The sympathetic nervous system (SNS), mediated by the sympathetic chain (trunk) and ganglia, is a major division of the autonomic nervous system. It is composed of general visceral afferent and efferent axons that allow for involuntary control of bodily functions via the hypothalamus.  The over...
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Circumcaval ureter

Circumcaval ureter, also known as retrocaval ureter, is a term used to describe an abnormal course of a ureter that encircles the inferior vena cava. Both of these terms are somewhat misleading, as this configuration is considered a developmental anomaly of the inferior vena cava (IVC).  Clinic...
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Persistent primitive trigeminal artery

Persistent primitive trigeminal artery (PPTA) is the most common type of the four persistent carotid-vertebrobasilar anastomoses. It is present in 0.1-0.6% of cerebral angiograms and is usually unilateral. In utero, the trigeminal artery supplies the basilar artery before the development of the...
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Butterfly vertebra

Butterfly vertebra, also sometimes known as a sagittal cleft vertebra or anterior rachischisis, is a type of vertebral anomaly that results from the failure of fusion of the lateral halves of the vertebral body because of persistent notochordal tissue between them. Pathology Butterfly vertebra...
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Infratemporal fossa

The infratemporal fossa is a complex space of the face that lies posterolateral to the maxillary sinus, below the skull base, and between the pharyngeal sidewall and mandibular ramus. It overlaps with the masticator space and prestyloid parapharyngeal space. Gross anatomy The infratemporal fos...
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Occipital vertebra

Occipital vertebrae are rare anatomical variants that result from incomplete or aberrant fusion of occipital bone ossification centers. There is a broad spectrum of occipital vertebrae, the more common variants include: third condyle (condylus tertius) basilar process prebasioccipital arch p...
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Posterior ciliary arteries

The posterior ciliary arteries are usually paired branches arising from the ophthalmic artery, one medial and one lateral, each giving off a number of branches that supply the uvea 1. Close to the optic nerve, are the short posterior ciliary arteries, usually numbering 16-20; these supply the p...

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