Abductor pollicis brevis
The abductor pollicis brevis is a thin subcutaneous muscle located laterally in the thenar eminence of the hand.
Summary
-
origin: mainly from the flexor retinaculum
- few fibres originate from the tubercles of scaphoid and trapezium and tendon of abductor pollicis longus
- accessory slips may originate from the long and short pollicial extensors (extensor pollicis longus and extensor pollicis brevis), the opponens pollicis or radial styloid process
- insertion: its medial fibres are attached by a thin, flat tendon to the radial side of the proximal phalangeal base in the pollex and lateral fibres join the pollicial dorsal digital expansion
- innervation: lateral branch of median nerve (C8 and T1)
- action: abducts the thumb and medially rotates it at the carpometacarpal and metacarpophalangeal joints
Related Radiopaedia articles
Anatomy: Upper limb
-
skeleton of the upper limb
- clavicle
- scapula
- humerus
- radius
- ulna
- carpal bones (mnemonic)
- metacarpals
- phalanges
- accessory ossicles of the upper limb
- accessory ossicles of the shoulder
- accessory ossicles of the elbow
-
accessory ossicles of the wrist (mnemonic)
- os centrale carpi
- os epilunate
- os styloideum
- os hamuli proprium
- lunula
- os triangulare
- trapezium secondarium
- os paratrapezium
- os radiostyloideum (persistent radial styloid)
- joints of the upper limb
-
shoulder joint
- articulations
- sternoclavicular joint
- acromioclavicular joint
- glenohumeral joint
- scapulocostal joint (scapulothoracic joint)
- suprahumeral joint
- variants
- associated structures
-
movements
- scapular retraction (adduction)
- scapular protraction (abduction)
- scapular elevation
- scapular depression
- arm abduction
- arm adduction
- arm flexion
- arm extension
- arm internal rotation (medial)
- arm external rotation (lateral)
- blood supply - scapular anastomosis
- ossification centres
- articulations
-
elbow joint
- proximal radioulnar joint
- ligaments
- associated structures
- alignment
- blood supply - elbow anastomosis
- development
-
wrist joint
- articulations
- ligaments
- associated structures
- alignment
- ossification
-
hand joints
- movements
- articulations
- carpometacarpal joint
-
metacarpophalangeal joint
- palmar ligament (plate)
- collateral ligament
-
interphalangeal joint
- palmar ligament (plate)
- collateral ligament
-
shoulder joint
- spaces of the upper limb
- muscles of the upper limb
- shoulder girdle
- anterior compartment of the arm
- posterior compartment of the arm
- anterior compartment of the forearm
- posterior compartment of the forearm (extensors)
-
hand (mnemonic)
- thenar muscles
-
hypothenar muscles
- abductor digiti minimi
- flexor digiti minimi brevis
- opponens digiti minimi
- palmaris brevis (technically not a hypothenar muscle)
- intermediate muscles
- accessory muscles
- blood supply to the upper limb
-
arteries
- subclavian artery (mnemonic)
- axillary artery
- brachial artery (proximal portion)
- ulnar artery
- radial artery
- veins
-
arteries
- innervation of the upper limb
- intercostobrachial nerve
-
brachial plexus (mnemonic)
- branches from the roots
- branches from the trunks
- branches from the cords
- lateral cord
- posterior cord
- medial cord
- terminal branches
- lymphatic drainage of the upper limb
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