Everything about The Axillary Nerve totally explained
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 carries nerve fibers from C5 and C6. The axillary nerve travels through the
quadrangular space with the
posterior circumflex humeral artery and vein.
Muscular and sensory innervation
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.
Branches
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 Teres Minor, 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.
Injury
The axillary nerve may be injured in anterior dislocations of the shoulder joint, compression of the axilla with a crutch or fracture of the surgical neck of the humerus. Injury to the nerve results in: -
1. Paralysis of the teres minor and deltoid muscles. Abduction of the shoulder is impaired.
2. Loss of sensation over a small part of the lateral upper arm
Additional images
Image:Brachial plexus.svg|Brachial plexus
Image:Gray810.png|Suprascapular and axillary nerves of right side, seen from behind.
Image:Gray811and813.PNG|Cutaneous nerves of right upper extremity.
Image:Gray812and814.PNG|Diagram of segmental distribution of the cutaneous nerves of the right upper extremity.
Image:Gray1236.png|Back of right upper extremity, showing surface markings for bones and nerves.
Further Information
Get more info on 'Axillary Nerve'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://axillary_nerve.totallyexplained.com">Axillary nerve Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
