Medial pectoral nerve
The medial pectoral nerve, also known as the medial anterior thoracic nerve arises from the medial cord of the brachial plexus and supplies both the pectoralis minor and major muscles.
Gross anatomy
Origin
The medial pectoral nerve arises from the medial cord of the brachial plexus with fibers arising from the eighth cervical and first thoracic nerve roots.
Course
The medial pectoral nerve arises posterior to the axillary artery. It curves anteriorly to lie between the axillary artery and vein then, after receiving a communicating branch from the lateral pectoral nerve (the ansa pectoralis) enters the deep surface of the pectoralis minor muscle. The medial pectoral nerve perforates the pectoralis minor muscle and enters the deep surface of pectoralis major supplying the lower sternocostal fibers of the muscle.
Branches and supply
The medial pectoral nerve supplies both the pectoralis minor muscle and sternocostal portions of the pectoralis major muscle.
Relations
The medial pectoral nerve lies posterior to the axillary artery and anterior to the axillary vein. Along its course it receives a communicating branch from the lateral pectoral nerve to form a loop (ansa pectoralis) which runs anteriorly to both the axillary artery and vein.
Variant anatomy
The medial pectoral nerve may arise directly from the anterior division of the inferior trunk of the brachial plexus.
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 epitriquetrum
- os styloideum
- os hamuli proprium
- lunula
- os triangulare
- trapezium secondarium
- os paratrapezium
- os radiostyloideum (persistent radial styloid)
- joints of the upper limb
-
pectoral girdle
-
shoulder joint
- articulations
- associated structures
- joint capsule
- bursae
- ligaments
-
movements
- scapulothoracic joint
- glenohumeral joint
- arm flexion
- arm extension
- arm abduction
- arm adduction
- arm internal rotation (medial rotation)
- arm external rotation (lateral rotation)
- circumduction
- blood supply - scapular anastomosis
- ossification centers
-
shoulder joint
-
elbow joint
- proximal radioulnar joint
- ligaments
- associated structures
- movements
- alignment
- blood supply - elbow anastomosis
- development
-
wrist joint
- articulations
-
ligaments
- intrinsic ligaments
- extrinsic ligaments
- radioscaphoid ligament
- dorsal intercarpal ligament
- dorsal radiotriquetral ligament
- dorsal radioulnar ligament
- volar radioulnar ligament
- radioscaphocapitate ligament
- long radiolunate ligament
- Vickers ligament
- short radiolunate ligament
- ulnolunate ligament
- ulnotriquetral ligament
- ulnocapitate ligament
- ulnar collateral ligament
- associated structures
- extensor retinaculum
- flexor retinaculum
- joint capsule
- movements
- alignment
- ossification centers
-
hand joints
- articulations
- carpometacarpal joint
-
metacarpophalangeal joints
- palmar ligament (plate)
- collateral ligament
-
interphalangeal joints
- palmar ligament (plate)
- collateral ligament
- movements
- ossification centers
- articulations
-
pectoral girdle
- 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)
- superficial
- deep
- hand (mnemonic)
- 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