This article lists

anatomical variations An anatomical variation, anatomical variant, or anatomical variability is a presentation of body structure with morphological features different from those that are typically described in the majority of individuals. Anatomical variations are categ ...

that are not deemed inherently pathological. {{incomplete list, date=December 2013

Accessory features

Bones

Cervical rib A cervical rib in humans is an extra rib which arises from the seventh cervical vertebra. Their presence is a congenital abnormality located above the normal first rib. A cervical rib is estimated to occur in 0.2% to 0.5% (1 in 200 to 500) of the ...

Fabella The fabella is a small sesamoid bone found in some mammals embedded in the tendon of the lateral head of the gastrocnemius muscle behind the lateral condyle of the femur. It is an accessory bone, an anatomical variation present in 39% of huma ...

* Foramen tympanicum * Supracondylar process of the humerus * Sternal foramen * Stafne bone cavity * Episternal ossicles *

Fossa navicularis magna Fossa navicularis magna (also known as ''pharyngeal fossa'' or ''phyaryngeal fovela'') is a variant bony depression found at the midline of the occipital part of clivus. This fossa was first described by Tourtual. Its prevalence ranges from 0.9 to ...

Transverse basilar fissure Transverse may refer to: *Transverse engine, an engine in which the crankshaft is oriented side-to-side relative to the wheels of the vehicle *Transverse flute, a flute that is held horizontally *Euler force, Transverse force (or ''Euler force'') ...

- or ''Saucer's fissure'' * Canalis basilaris medianus *

Craniopharyngeal canal The craniopharyngeal canal is a human anatomical feature sometimes found in the sphenoid bone opening to the sella turcica. It is a canal (a passage or channel) sometimes found extending from the anterior part of the fossa hypophyseos of the spheno ...

Intermediate condylar canal Intermediate may refer to: * Intermediate 1 or Intermediate 2, educational qualifications in Scotland * Intermediate (anatomy), the relative location of an anatomical structure lying between two other structures: see Anatomical terms of location ...

* Foramen arcuale * Os odontoideum * Os acromiale * Ossiculum terminale (of dens) * Scapular foramina and tunnels

Muscles

Accessory soleus muscle The accessory soleus muscle is an accessory muscle of the calf which is rarely present in humans; it is, however, the most common accessory muscle of the ankle. The muscle inserts on the anterior aspect of the soleus muscle or on the posterior a ...

* Axillary arch *

Epitrochleoanconeus muscle The epitrochleoanconeus muscle (anconeous epitrochlearis muscle, anconeus-epitrochlearis or anconeus sextus) is a small accessory muscle of the arm which runs from the back of the inner condyle of the humerus over the ulnar nerve to the olecranon ...

- or ''anconeous epitrochlearis'' *

Extensor medii proprius muscle The extensor medii proprius (so called the ''extensor digiti medii'') is a rare anatomical variant in the extensor compartment of the forearm. The aberrant muscle is analogous to the extensor indicis with the insertion being the middle finger inst ...

* Extensor digitorum brevis manus muscle *

Extensor indicis et medii communis muscle The extensor indicis et medii communis is a rare anatomical variant in the extensor compartment of forearm. This additional muscle lies in the deep extensor layer next to the extensor indicis proprius and the extensor pollicis longus. The characte ...

* Extensor pollicis et indicis communis muscle * Extensor carpi radialis tertius muscle - or ''extensor carpi radialis accessorius'' * Linburg-Comstock variation - or conjoint flexor pollicis longus and flexor digitorum profundus of the index * Sternalis muscle - or ''rectus thoracis'' * Psoas minor muscle * Palmaris profundus muscle *

Pterygoideus proprius muscle Pterygoid, from the Greek for 'winglike', may refer to: * Pterygoid bone, a bone of the palate of many vertebrates * Pterygoid processes of the sphenoid bone ** Lateral pterygoid plate ** Medial pterygoid plate * Lateral pterygoid muscle * Medi ...

* Styloauricularis muscle * Transversus nuchae muscle *

Accessory popliteus muscle Accessory may refer to: * Accessory (legal term), a person who assists a criminal In anatomy * Accessory bone * Accessory muscle * Accessory nucleus, in anatomy, a cranial nerve nucleus * Accessory nerve In arts and entertainment * Accessory ( ...

* Tensor fasciae suralis muscle * Sternoclavicularis anticus muscle * Gluteoperinealis muscle * Gantzer's muscle *

Levator claviculae muscle In human anatomy, the levator claviculae is a very rare accessory muscle, accessory and Human vestigiality, vestigial skeletal muscle in the posterior triangle of the neck. It originates on the transverse processes of the upper cervical vertebrae ...

* Chondrocoracoideus muscle

Vasculature

* Double cystic artery

Glands

* Accessory parotid gland * Zuckerkandl's tubercle

Organs

* Accessory spleen * Azygos lobe of the lung * Tracheal bronchus * Hirsuties coronae glandis * Cardiac bronchus

Other

Accessory pancreatic duct The pancreatic duct, or duct of Wirsung (also, the major pancreatic duct due to the existence of an accessory pancreatic duct), is a duct joining the pancreas to the common bile duct. This supplies it with pancreatic juice from the exocrine pancr ...

Accessory nail of the fifth toe The accessory nail of the fifth toe, also known as petaloid toenail, is a physical trait of the small toe, where a minuscule "sixth toenail" is present in the outer corner of the nail situated on the smallest toe. Trait The trait can be observed ...

* Darwin's tubercle * Vein of foramen caecum * Osborne's ligament * Gastropancreatic ligament * Diagonal ear lobe crease *

Preauricular sinus Preauricular sinuses and preauricular cysts are two common congenital malformation, congenital malformations. Each involves the external ear. The difference between them is that a cyst does not connect with the skin, but a sinus does. Frequency o ...

Lacking features

Muscles

Risorius The risorius muscle is a muscle of facial expression. It arises from the fascia over the parotid gland, and inserts into the angle of the mouth. It is supplied by the facial nerve (CN VII). It may be absent or asymmetrical in some people. It retr ...

* Psoas minor * Absence of the

palmaris longus The palmaris longus is a muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much long ...

* Dividement of the

piriformis The piriformis muscle () is a flat, pyramidally-shaped muscle in the gluteal region of the lower limbs. It is one of the six muscles in the lateral rotator group. The piriformis muscle has its origin upon the front surface of the sacrum, and in ...

* Missing or underdeveloped

pectoralis major The pectoralis major () is a thick, fan-shaped or triangular convergent muscle, situated at the chest of the human body. It makes up the bulk of the chest muscles and lies under the breast. Beneath the pectoralis major is the pectoralis minor, ...

is called Poland's syndrome

Other

Appendix Appendix, or its plural form appendices, may refer to: __NOTOC__ In documents * Addendum, an addition made to a document by its author after its initial printing or publication * Bibliography, a systematic list of books and other works * Index (pu ...

* Agenesis of

wisdom teeth A third molar, commonly called wisdom tooth, is one of the three molars per quadrant of the human dentition. It is the most posterior of the three. The age at which wisdom teeth come through ( erupt) is variable, but this generally occurs betw ...

* Empty

sella turcica The sella turcica ( Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalometr ...

Varying features

Bones

Sesamoid bone In anatomy, a sesamoid bone () is a bone embedded within a tendon or a muscle. Its name is derived from the Arabic word for 'sesame seed', indicating the small size of most sesamoids. Often, these bones form in response to strain, or can be prese ...

of the second, third, fourth and fifth finger * Manubriosternal fusion * Sternoxiphoidal fusion

Muscles

Myocardial bridge A myocardial bridge (MB) is a congenital heart defect in which one of the coronary arteries tunnels through the heart muscle itself (myocardium). In normal patients, the coronary arteries rest on top of the heart muscle and feed blood down into s ...

Nerves

* Nerve of Mckenzie

Vasculature

* Artery of Percheron * Variation of basilic vein * Median artery * Thyroid ima artery * Superficial ulnar artery * Marginal artery of the colon * Persistent primitive olfactory artery * Arc of Bühler * Stapedial artery *

Hypoglossal artery The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a cranial nerve that innervates all the extrinsic and intrinsic muscles of the tongue except for the palatoglossus, which is innervated by ...

* Corona mortis

Other

Anisocoria Anisocoria is a condition characterized by an unequal size of the eyes' pupils. Affecting up to 20% of the population, anisocoria is often entirely harmless, but can be a sign of more serious medical problems. Causes Anisocoria is a common condit ...

* Crease of the upper eyelid – having either a "single" or "double" eyelid ** Epicanthic fold * Lateral arcuate ligament * Horseshoe kidney - also known as ''ren arcuatus''

Accessory features

Bones

Muscles

Vasculature

Glands

Organs

Other

Lacking features

Muscles

Other

Varying features

Bones

Muscles

Nerves

Vasculature

Other

See also