Items tagged “anatomy”

152 results found
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Bill bar

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

Buford complex is a congenital glenoid labrum variant where the anterosuperior labrum is absent in the 1-3 o'clock position and the middle glenohumeral ligament is thickened (cord-like). It originates directly from the superior labrum adjacent to the bicipital labral complex and inserts onto the...
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Cavum vergae

The cavum vergae (CV), along with the cavum septum pellucidum (CSP) that lies immediately anterior to it, is a persistence of the embryological fluid-filled space between the leaflets of the septum pellucidum and is a common anatomical variant.  Terminology The cavum vergae has also been refer...
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Cranial nerves

The cranial nerves are the 12 paired sets of nerves that arise from the cerebrum or brainstem and leave the central nervous system through cranial foramina rather than through the spine. The cranial nerves are numbered one to twelve, always using the Roman numerals, I to XII. Most have cranial n...
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Internal auditory canal nerves (mnemonic)

A mnemonic to remember the relative position of nerves inside the internal auditory canal (IAC) is: Seven up, Coke down Anatomy Four nerves pass through the IAC: facial nerve (CN VII) three components of the vestibulocochlear nerve (CN VIII) cochlear nerve (CN VIIIc) superior vestibular n...
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Trochlear nerve

The trochlear nerve is the fourth cranial nerve and is the motor nerve of the superior oblique muscle of the eye.  It can be divided into four parts: nucleus and an intraparenchymal portion cisternal portion cavernous sinus portion orbital portion Gross anatomy Nucleus and intraparenchy...
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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...
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Dura mater

The dura mater, also known as the pachymeninx (plural: pachymeninges), is the tough outer layer of the meninges that surrounds the central nervous system and is pierced by the cranial nerves, the internal carotid arteries and the vertebral arteries.  Intracranially, it is formed by two layers: ...
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Liver

The liver is the largest abdominal organ. It plays a major role in metabolism and has a number of functions, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, and detoxification. It is one of the very few organs that has the ability to re...
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Medulla oblongata

The medulla oblongata (or simply the medulla) is the most caudal part of the brainstem between the pons superiorly and spinal cord inferiorly. It is the transition from the spinal cord to the brain. The medulla contains the vital autonomic cardiovascular and respiratory centers controlling hear...
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Intervertebral disc

Intervertebral discs form the articulations between adjacent vertebral bodies from C2 to S1, thus forming 23 in total (although segmentation variations are not uncommon). Together they account for ~25% of the total height of the vertebral column which decreases with age as disc height is lost th...
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Müllerian duct anomalies

Müllerian duct anomalies (MDAs) are congenital abnormalities that occur when the Müllerian ducts (paramesonephric ducts) do not develop correctly. This may be as a result of complete agenesis, defective vertical or lateral fusion, or resorption failure. Epidemiology MDAs are estimated to occur...
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Thymus

The thymus (plural: thymi) is a T-cell producing lymphoid organ in the anterior mediastinum that plays a role in the development of the immune system particularly, maturation of T-cells. It typically has a retrosternal location and hence may mimic retrosternal pathology. Gross anatomy It is re...
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Right coronary artery

The right coronary artery (RCA) is one of the two main coronary arteries that supply the heart with oxygenated blood. Gross anatomy Origin The right coronary artery arises from its ostium in the right sinus of Valsalva, found between the aortic valve annulus and the sinotubular junction.  C...
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Carpal bones (mnemonic)

Mnemonics of the carpal bones are numerous and useful for memorizing the order and location of the bones. Some mnemonics name the carpal bones in a circle, starting with the proximal row from the scaphoid towards the pinky (small finger) and then the distal row starting from the hamate towards ...
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Anterior ankle tendons (mnemonic)

A mnemonic that refers to the order of the anterior ankle tendons around the ankle is: Tom Hates Dick The mnemonic can be used to remember the order of the tendons from medial to lateral as they pass under the extensor retinaculum of the ankle.  Mnemonic T: tibialis anterior H: extensor hal...
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Gallbladder

The gallbladder is a pear-shaped musculomembranous sac located along the undersurface of the liver. It functions to accumulate and concentrate bile between meals. Gross anatomy Macroscopic The normal adult gallbladder measures from 7-10 cm in length and 3-4 cm in transverse diameter 6. The ga...
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Trigeminal nerve branches (mnemonic)

A mnemonic for remembering the names of the skull foramina that the division of the trigeminal nerve (CN V) pass through is: Standing Room Only Mnemonic S: superior orbital fissure (ophthalmic division of trigeminal nerve) R: foramen rotundum (maxillary division of trigeminal nerve) O: fora...
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Sternalis muscle

The sternalis muscle is an uncommon anatomic variant of the chest wall musculature and is of uncertain etiology and function. Its importance lies in that it should not be mistaken for a pathological lesion.  Epidemiology Cadaveric studies have shown that the muscle is present in ~5% (range 1-8...
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Horizontal fissure

The horizontal fissure (also called the minor fissure) is a unilateral structure in the right lung that separates the right middle lobe from the right upper lobe. Gross anatomy The horizontal fissure arises from the right oblique fissure and follows the 4th intercostal space from the sternum u...