List of anatomical variations
This article provides a comprehensive list of anatomical variations, which are naturally occurring differences in human morphology. These variations are not considered defects or abnormalities but rather normal deviations that do not inherently indicate pathology.
Head and neck
Skeletal variations
- Occipitalization of the atlas
- Basilar tubercle of clivus
- Tubercle at the anterior rim of foramen magnum
- Clivus bony canal
- Condylus tertius
- Epipteric bone
- Foramen tympanicum
- Ossified petrosphenoid ligament
- Ossification anomalies of the atlas
- Craniopharyngeal canal
- Canalis basilaris medianus
- Fossa navicularis magna
- Transverse basilar fissure
- Arcus praebasiocipitalis
- Stafne bone cavity
- Arcuate foramen
- Ossiculum terminale
- Os odontoideum
- Intermediate condylar canal
- Innominate canal of Arnold
- Arcus praebasiocipitalis
- Inca bone
- Haller cell
- Sphenoethmoidal air cell
- Accessory maxillary ostium
- Thyroid foramen
- Collateral eminence
- Wormian bones
Muscular variations
- Levator glandulae thyroidea
- Accessory belly of digastric muscle
- Atlantomastoid muscle
- Styloauricularis muscle
- Transversus nuchae muscle
- Pterygoideus proprius muscle
- Levator claviculae muscle
- Levator glandulae thyroidea muscle
- Cleidoatlanticus muscle
- Cleidocervical muscle
- Cleidofascialis muscle
- Cleidohyoideus muscle
- Cleidomastoideus muscle
- Cleido-occipitalis cervicalis muscle
- Cricocorniculate muscle
- Cricohyoid muscle
- Sternoclavicularis anticus muscle
- Styloauricularis muscle
Vascular variations
- Persistent primitive olfactory artery
- Artery of Percheron
- Stapedial artery
- Thyroid ima artery
- Fourth thyroid vein
- Falcine sinus
- Hypoglossal artery
- Persistent left superior vena cava
- Trigeminal artery
Nervous variations
- Trigeminal nerve duplication
- Aberrant facial nerve course
- Accessory hypoglossal nerve
Other variations
- Preauricular sinus
- Supernumerary nipple
- Darwin's tubercle
- Anisocoria
- Diagonal earlobe crease
- Empty sella turcica
- Epicanthic fold
- Crease of the upper eyelid
- Zuckerkandl's tubercle
- Pyramidal lobe of thyroid gland
Vertebral column and ribs
Skeletal variations
- Atlanto-occipital fusion
- Butterfly vertebrae
- Cervical ribs
- Coccygeal ribs
- Block vertebrae
- Sagittal cleft vertebrae
- Lumbosacral transitional vertebrae
- Split cord malformation
- Sternal cleft
- Spondylolisthesis
- Oppenheimer's ossicle
- Spondylolysis
- Sprengel's deformity
Thorax
Skeletal variations
- Sternal foramen and xiphoid foramen
- Episternal ossicles
- Manubriosternal fusion
- Sternoxiphoidal fusion
- Bifid xiphoid process
- Bifid rib
Muscular variations
- Sternalis muscle
- Costocoracoideus muscle
Other variations
- Azygos lobe of the lung
- Tracheal bronchus
- Cardiac bronchus
- Supernumerary lung fissures
- Horseshoe lung
Upper limb
Skeletal variations
- Bifurcated clavicle
- Coracoclavicular joint
- Os acromiale
- Carpal coalition
- Carpal boss
- Bipartite capitate
- Supracondylar process of the humerus
- Scapular foramina and tunnels
Muscular variations
- Accessory subscapularis muscle
- Gantzer's muscle
- Chondroepitrochlearis muscle
- Coracocapsularis muscle
- Costodeltoideus muscle
- Axillary arch muscle
- Epitrochleoanconeus muscle
- Extensor medii proprius muscle
- Extensor digitorum brevis manus muscle
- Extensor indicis et medii communis muscle
- Extensor pollicis et indicis communis muscle
- Extensor carpi radialis tertius muscle
- Linburg-Comstock variation
- Palmaris profundus muscle
- Flexor carpi radialis profundus muscle
- Ulnaris quinti muscle
- Pisiuncinatus muscle
- Sternohumeralis muscle
- Sternochondrocoracoideus muscle
- Subscapularis minor muscle
- Tensor semivaginae articulations humeroscapularis muscle
- Thoracobrachialis muscle
Vascular variations
- Alar thoracic artery
- Median artery
- Superficial ulnar artery
- Variation of the basilic vein
Nervous variations
- Bifid median nerve
- Nerve of McKenzie
- Martin-Gruber anastomosis
- Riché-Cannieu anastomosis
- Berrettini anastomosis
- Froment-Rauber nerve
Other variations
Lower limb
Skeletal variations
- Femoral anteversion/retroversion
- Os tibiale externum
- Fabella
- Calcaneonavicular coalition
- Accessory navicula
- Talocalcaneal coalition
- Cyamella
- Sesamoid bone of the second, third, fourth, and fifth finger
- Talus accessorius
- Os trigonum
Muscular variations
- Accessory soleus muscle
- Accessory popliteus muscle
- Adductor minimus muscle
- Tensor fasciae suralis muscle
- Gastrocnemius tertius muscle
- Gluteoperinealis muscle
- Gluteus quartus muscle
- Popliteus biceps muscle
- Fibularis quartus muscle
- Peroneocalcaneus internus muscle
Vascular variations
Nervous variations
- Sciatic nerve variations in relation to the piriformis muscle
Abdomen
Muscular variations
- Interfoveolar muscle
- Saphenous muscle
- Pubotransversalis muscle
Vascular variations
Other variations
- Accessory spleen
- Annular pancreas
- Bifid pancreas tail
- Double common bile duct
- Agenesis of vermiform appendix
- Colon duplication
- Accessory pancreatic duct
- Pancreas divisum
- Gastropancreatic ligament
Pelvis
Vascular variations
- Uterine artery anastomoses variations
Other variations
- Bladder exstrophy
- Renal artery anomalies
- Splenogonadal fusion
- Supernumerary ovaries
- Horseshoe kidney
- Hirsuties coronae glandis