Medial cutaneous nerve of the arm
The medial cutaneous nerve of the arm, also known as the lesser internal cutaneous nerve of arm, is a branch of the medial cord of the brachial plexus and supplies the skin of the medial side of the arm as far distal as the medial epicondyle.
Gross anatomy
Origin
The medial cutaneous nerve of the arm arises from the medial cord of the brachial plexus and receives fibers form the eighth cervical and first thoracic nerve roots.
Course
The medial cutaneous nerve of the arm is the smallest and most medial of the branches of the brachial plexus. Originally posterior to the axillary vein, it then comes to lie on the medial side of the vein. In the arm it descends along the medial side of the brachial vein to the mid-portion of the arm where it pierces the deep fascia of the arm to give off its terminal cutaneous branches.
Branches and supply
- skin of the medial side of the arm as far distal as the medial epicondyle of the humerus and olecranon of ulna
Relations
- courses along the medial side of the axillary and brachial veins
- shortly after branching from the brachial plexus the medial cutaneous nerve of the arm communicates with the intercostobrachial nerve, the lateral cutaneous branch of the second intercostal nerve which supplies the skin of the axilla.
Variant anatomy
The medial cutaneous nerve of the arm is not always protected under the axillary vein and is consequently sometimes subject to injury during the dissection of axillary lymph nodes.
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
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shoulder joint
- articulations
- associated structures
- joint capsule
- bursae
- ligaments
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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
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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
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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
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- radial artery
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arteries
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- intercostobrachial nerve
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brachial plexus (mnemonic)
- branches from the roots
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- lateral cord
- posterior cord
- medial cord
- terminal branches
- lymphatic drainage of the upper limb