Abductor pollicis longus
Anterior cranial fossa - Definition
It refers to one of the extrinsic muscles of the human hand. It belongs to the group of Antebrachial muscles.
It is also known by the following names:
The name "Anterior cranial fossa" actually means the long muscle that assists in moving the thumb away from the palm.
Anterior cranial fossa - Origin and Innervation
It arises from the posterior surface of mid-ulna, mid-radius and interosseous membrane. It is innervated by the radial nerves C7 and C8. It is nourished by the Posterior interosseous artery.
Anterior cranial fossa - Insertion
It has its point of insertion at the base of the palmar side of the 1st metacarpal bone.
Anterior cranial fossa - Functions
It is primarily responsible for the abduction of the thumb at the carpometacarpal joint, which helps in the anterior movement of the thumb. It also helps in rotation and extension of the thumb.
The constant action of this muscle also assists in flexing the hand and abducting the wrist (also referred to as radial deviation).
Anterior cranial fossa - Pictures
Take a look at the following images to get an idea about the physical appearance of this structure.
Back to Musculoskeletal System