Axillary nerve

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Nerve: Axillary nerve
Click image to enlarge - axillary nerve is visible in gray near center
The suprascapular, axillary, and radial nerves. (Axillary labeled at upper right.)
Latin nervus axillaris
Gray's subject #210 934
Innervates Deltoid, teres minor
From Posterior cord
Dorlands/Elsevier n_05/12565259

The axillary nerve is a nerve of the human body, that comes off the posterior cord of the brachial plexus at the level of the axilla (armpit) and carriers nerve fibers from C5 and C6. The axillary nerve travels through the quadrangular space with the posterial circumflex humeral artery and vein.

It supplies two muscles, deltoid (a muscle of the shoulder), and teres minor (one of the rotator cuff muscles).

The axillary nerve also carries sensory information from the shoulder joint, as well as the skin covering the inferior region of the deltoid muscle (which is innervated by the Superior Lateral Cutaneous Nerve branch of the Axillary nerve).

When the axillary nerve splits off from the posterior cord, the continuation of the cord is the radial nerve.

[edit] Details from Gray's Anatomy

The Axillary Nerve (n. axillaris; circumflex nerve) arises from the posterior cord of the brachial plexus, and its fibers are derived from the fifth and sixth cervical nerves. It lies at first behind the axillary artery, and in front of the Subscapularis, and passes downward to the lower border of that muscle. It then winds backward, in company with the posterior humeral circumflex artery, through a quadrilateral space bounded above by the Subscapularis, below by the Teres major, medially by the long head of the Triceps brachii, and laterally by the surgical neck of the humerus, and divides into an anterior and a posterior branch.

  • The anterior branch (upper branch) winds around the surgical neck of the humerus, beneath the Deltoideus, with the posterior humeral circumflex vessels, as far as the anterior border of that muscle, supplying it, and giving off a few small cutaneous branches, which pierce the muscle and ramify in the skin covering its lower part.
  • The posterior branch (lower branch) supplies the Teres minor and the posterior part of the Deltoideus; upon the branch to the Teres minor an oval enlargement (pseudoganglion) usually exists. The posterior branch then pierces the deep fascia and is continued as the lateral brachial cutaneous nerve, which sweeps around the posterior border of the Deltoideus and supplies the skin over the lower two-thirds of the posterior part of this muscle, as well as that covering the long head of the Triceps brachii.

The trunk of the axillary nerve gives off an articular filament which enters the shoulder-joint below the Subscapularis

[edit] External links

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.

Brachial plexus

supraclavicular: dorsal scapular - suprascapular - to the subclavius - long thoracic

infraclavicular: lateral cord: musculocutaneous (lateral cutaneous of forearm) - lateral pectoral - lateral head of median

medial cord: medial pectoral - medial cutaneous of forearm - medial cutaneous cutaneous of arm - ulnar (palmar branch - dorsal branch) - medial head of median

posterior cord: upper subscapular - lower subscapular - thoracodorsal - axillary (superior lateral cutaneous of arm) - radial (muscular - posterior cutaneous of arm - posterior cutaneous of forearm - superficial branch - deep branch)

median: anterior interosseous - palmar - proper palmar digital - common palmar digital

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