Items tagged “anatomy”

Bill bar (TA: crista verticalis) also known as the vertical crest, 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...

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...

The cranial nerves (TA: nervi craniales) are the twelve 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 Roman numerals, i.e. I ...

A mnemonic to remember the relative position of nerves inside the internal auditory canal (IAC) is: Seven up, Coke down A variation may include the addition of: V8 on the back shelf Anatomy Four nerves pass through the IAC: facial nerve (CN VII) three components of the vestibulocochlear n...

The trochlear nerve is the fourth (CN IV) and thinnest cranial nerve. It exits the midbrain posteriorly, eventually passes into the cavernous sinus and into the orbit where it supplies superior oblique muscle with motor fibers (TA: nervus trochlearis or nervus cranialis IV).  Gross anatomy Nuc...

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...

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:...

The liver is the largest abdominal organ. It plays a major role in metabolism and has many 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 regenerat...

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...

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...

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...

The thymus (plural: thymi) is a lymphoid organ in the anterior mediastinum responsible for the production and maturation of T-cells until puberty. It is a vital component of the immune system and plays a role in prevention of cancer 12, infection and autoimmunity 11. Gross anatomy It is relati...

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...