Items tagged “anatomy rewrite”

78 results found

Abducens nerve

The abducens nerve is the sixth cranial nerve. It courses from its nucleus located in the dorsal pons to its innervation of the lateral rectus muscle and can be divided into four parts: nucleus and intraparenchymal portion cisternal portion cavernous sinus portion orbital portion Gross anat...


The cerebellum, meaning "the little brain", sits at the base of the brain in the posterior cranial fossa below the tentorium and behind the brainstem.  Gross anatomy The cerebellum has the following features: three surfaces: anterior (petrosal), superior (tentorial), inferior (suboccipital) ...

Bill bar

Bill bar is a landmark that divides the superior compartment of the internal acoustic meatus into an anterior and posterior compartment. Anterior to Bill's bar, in the anterior superior quadrant, are the facial nerve (CN VII) and nervus intermedius, and posterior to it in the posterior superior ...

Caval variants

Many caval variants exist, due to the complex embryology of the venous system. These are important for a number of reasons:  not to confuse them with pathology suggest the presence of frequently associated other abnormalities planning of vascular intervention or surgery Types superior vena ...

Cerebral vascular territories

An understanding of cerebral vascular territories is important in understanding stroke and complications from surgery and endovascular procedures.  Although one could be excused for thinking that within the brain, such a carefully organised organ, blood supply would be constant, the truth is th...

Circle of Willis

The Circle of Willis is an arterial polygon formed as the internal carotid and vertebral systems anastomose around the optic chiasm and infundibulum of the pituitary stalk in the suprasellar cistern. This communicating pathway allows equalization of blood-flow between the two sides of the brain,...

Fallopian canal

The Fallopian (facial) canal refers to a bony canal through which the facial nerve traverses the petrous temporal bone, from the internal acoustic meatus to the stylomastoid foramen. It is, for those of you fond of trivia, the longest bony canal through which a nerve passes. It is also responsi...


The hippocampus is an important component of the human brain, situated in the temporal lobe. It plays a role in information processing and the reproductive cycle and is involved in Alzheimer disease. Gross anatomy Location The hippocampus lies in the hippocampal sulcus immediately below the f...

Intracranial arteries (variants)

Intracranial arterial variants, of which there are many, are collectively common. Their clinical significance may be variable but knowledge and recognition of these variants is fundamental, especially if surgical or endovascular treatments (e.g. for acute stroke, aneurysms or other vascular path...

Muscles of mastication

The muscles of mastication can be divided into primary and secondary groups according to whether they connect the mandible directly to the skull or if they attach to other structures in the neck, e.g. hyoid, thyroid cartilage. Primary temporalis muscle masseter muscle medial pterygoid muscle...

Pancreatic ducts

The pancreatic ductal embryology is moderately complicated, leading to a number of anatomical variants of the pancreatic ducts, many of which are clinically significant. The normal arrangement is for the entire pancreas to be drained via a single duct, to the ampulla of Vater through the sphinc...

Rotator cuff interval

The rotator cuff interval is a triangular space between the tendons of subscapularis and supraspinatus and the base of the coracoid process. Gross anatomy It is roofed by the rotator interval capsule, which is principally made up of the coracohumeral ligament. It contains the tendon of the lon...

Superior orbital fissure

The superior orbital fissure is the communication between the cavernous sinus and the apex of the orbit. It is straddled by the tendinous ring which is the common origin of the four rectus muscles (extraocular muscles). Gross anatomy Boundaries medial: body of sphenoid superior: lesser wing ...

Vertebral anomalies

The vertebral column is affected by a range of anatomical variants of the body and/or neural arch as well as accessory ossicles. Knowledge of basic vertebral anatomy and ossification is essential for describing and understanding the range of anomalies. Variant anatomy Vertebral body hemiverte...

Couinaud classification of hepatic segments

The Couinaud classification (pronounced kwee-NO) is currently the most widely used system to describe functional liver anatomy. It is the preferred anatomy classification system as it divides the liver into eight independent functional units (termed segments) rather than relying on the tradition...

Internal acoustic canal

The internal acoustic canal (IAC), also known as the internal auditory canal or meatus (IAM), is a bony canal within the petrous portion of the temporal bone that transmits nerves and vessels from within the posterior cranial fossa to the auditory and vestibular apparatus. Gross anatomy The op...

Internal carotid artery

The internal carotid artery (ICA) is a terminal branch of the common carotid artery.  Gross anatomy Origin It arises most frequently between C3 and C5 vertebral level, where the common carotid bifurcates to form the internal carotid and the external carotid artery (ECA). Variations in origin...


The cervix or uterine cervix is the lower constricted segment of the uterus providing the passage between the uterus proper and the vagina.  Gross anatomy The cervix is somewhat conical in shape, with its truncated apex directed posteriorly and inferiorly. The inferior aspect of the cervix pro...

Eustachian tube

The Eustachian tube is the channel through which the tympanic cavity communicates with the nasopharynx. It is approximately 36 mm in length and is directed downward, forward, and medially, forming an angle of about 45 degrees with the sagittal plane and one of 30 to 40 degrees with the horizonta...

Maxillary artery

The (internal) maxillary artery is the larger of the two terminal branches of the external carotid artery.  Origin and course The maxillary artery's origin is behind the neck of the mandible, at first, it is embedded in the substance of the parotid gland. From there it passes anterior between ...

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