Nerve: Brachial plexus
The right brachial plexus with its short branches, viewed from in front.
Latin	plexus brachialis
Gray's	subject #210 930
From	C5, C6, C7, C8, T1
MeSH	Brachial+plexus
Dorlands / Elsevier	p_24/12647576

The brachial plexus is an arrangement of nerve fibres, running from the spine, formed by the ventral rami of the lower cervical and upper thoracic nerve roots, specifically from above the fifth cervical vertebra to underneath the first thoracic vertebra (C5-T1). Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. This is a list of the subjects in Gray's Anatomy: IX Neurology The cervical spinal nerve 5 (C5 is a Spinal nerve of the Cervical segment. The cervical spinal nerve 6 (C6 is a Spinal nerve of the Cervical segment. The cervical spinal nerve 7 (C7 is a Spinal nerve of the Cervical segment. The cervical spinal nerve 8 (C8 is a Spinal nerve of the Cervical segment. The thoracic spinal nerve 1 (T1 is a Spinal nerve of the Thoracic segment. Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Elsevier, the world's largest Publisher of Medical and Scientific literature, forms part of the Reed Elsevier group In Human anatomy, the vertebral column ( backbone or spine) is a column of 34 Vertebrae the Sacrum, Intervertebral The ventral ramus ( anterior ramus, anterior branch, anterior divisions of the spinal nerves) supply the antero-lateral parts of the trunk and the limbs In Vertebrates cervical vertebrae (singular vertebra) are those vertebrae immediately behind (posterior to the Skull. The 12 thoracic vertebrae compose the middle segment of the Vertebral column, between the Cervical vertebrae and the Lumbar vertebrae. The cervical spinal nerve 5 (C5 is a Spinal nerve of the Cervical segment. The thoracic spinal nerve 1 (T1 is a Spinal nerve of the Thoracic segment. It proceeds through the neck, the axilla (armpit region) and into the arm. The axilla (or armpit, underarm, or oxter) is the area on the human body directly under the joint where the Arm connects to the Shoulder

Function

The brachial plexus is responsible for cutaneous and muscular innervation of the entire upper limb, with two exceptions: the trapezius muscle innervated by the spinal accessory nerve and an area of skin near the axilla innervated by the intercostobrachialis nerve. In Human anatomy, the trapezius is a large Superficial Muscle which extends longitudinally from the occipital bone to the lower thoracic vertebrae In Anatomy, the accessory nerve is a Nerve that controls specific Muscles of the neck The intercostobrachial nerves are Cutaneous branches of the Intercostal nerves Second intercostal nerve The Lateral cutaneous branch of

Therefore, brachial plexus lesions can lead to severe functional impairment. Brachial plexus lesions are classified as either traumatic or obstetric

Anatomy

Path

One can remember the order of brachial plexus elements by way of the mnemonic, "Read The Damn Cadaver Book" (Or, alternatively, Randy Travis Drinks Cold Beer") - Roots, Trunks, Divisions, Cords, Branches^[1] or - Roots, Trunks, Divisions, Cords, Collateral/Pre-terminal Branches, and (Terminal) Branches. Randy Travis (born Randy Bruce Traywick, May 4, 1959 in Marshville North Carolina) is an American multiple Grammy Award - and

• The five roots are the five anterior rami of the spinal nerves, after they have given off their segmental supply to the muscles of the neck. The ventral ramus ( anterior ramus, anterior branch, anterior divisions of the spinal nerves) supply the antero-lateral parts of the trunk and the limbs The term spinal nerve generally refers to the mixed spinal Nerve, which is formed from the dorsal and ventral roots that come out of the Spinal cord. The neck is the part of the Body on many limbed Vertebrates that distinguishes the head from the Torso or trunk

• These roots merge to form three trunks:
  • "superior"^[2] or "upper" (C5-C6)
  • "middle"^[3] (C7)
  • "inferior"^[4] or "lower" (C8-T1)

• Each trunk then splits in two, to form six divisions:
  • anterior division^[5] of the upper, middle and lower trunks
  • posterior division^[6] of the upper, middle, and lower trunks

• These six divisions will regroup to become the three cords. The cervical spinal nerve 5 (C5 is a Spinal nerve of the Cervical segment. The cervical spinal nerve 6 (C6 is a Spinal nerve of the Cervical segment. The cervical spinal nerve 7 (C7 is a Spinal nerve of the Cervical segment. The cervical spinal nerve 8 (C8 is a Spinal nerve of the Cervical segment. The thoracic spinal nerve 1 (T1 is a Spinal nerve of the Thoracic segment. The cords are named by their position in respect to the axillary artery. In Human anatomy, the axillary artery is a large Blood vessel that conveys oxygenated Blood to the lateral aspect of the Thorax, the Axilla
  • The posterior cord is formed from the three posterior divisions of the trunks (C5-T1)
  • The lateral cord is the anterior divisions from the upper and middle trunks (C5-C7)
  • The medial cord is simply a continuation of the anterior division of the lower trunk (C8-T1)

• The branches are listed below. The posterior cord is a division of the Brachial plexus. It consists of contributions from all of the roots of the brachial plexus The Lateral cord is a division of the Brachial plexus. The lateral cord gives rise to the following nerves The Lateral pectoral nerve, C5 C6 and C7 The Medial cord is a division of the Brachial plexus. The medial cord gives rise to the following nerves The Median pectoral nerve, C8 and T1 to Most branch from the cords, but a few branch (indicated in italics) directly from earlier structures. The five in bold are considered "terminal branches".

Diagram

Specific branches

Additional images

Brachial plexus with areas of roots, trunks, divisions and cords marked. Cutaneous innervation refers to the area of the Skin which is supplied by a specific Nerve, that is by a Cutaneous nerve. The dorsal scapular nerve arises from the Brachial plexus, usually from the plexus root ( anterior/ventral ramus) of C5 The cervical spinal nerve 5 (C5 is a Spinal nerve of the Cervical segment. The rhomboid muscles, often simply called the rhomboids, are Rhombus -shaped muscles associated with the Scapula and are chiefly responsible for its The levator scapulae is situated at the back and side of the neck The long thoracic nerve ( external respiratory nerve of Bell; posterior thoracic nerve) supplies the Serratus anterior. The cervical spinal nerve 6 (C6 is a Spinal nerve of the Cervical segment. The cervical spinal nerve 7 (C7 is a Spinal nerve of the Cervical segment. The serratus anterior is a muscle that originates on the surface of the upper eight ribs at the side of the chest and inserts along the entire anterior length of the medial border of the The nerve to the Subclavius (or subclavian nerve) is a small filament which arises from the point of junction of the fifth and sixth Cervical nerves It descends The Subclavius is a small triangular muscle placed between the Clavicle and the First rib. The suprascapular nerve arises from the trunk formed by the union of the fifth and sixth Cervical nerves. The supraspinatus is a relatively small muscle of the upper limb that takes its name from its origin from the Supraspinous fossa superior to the spine of the Scapula The Infraspinatus muscle is a thick triangular Muscle, which occupies the chief part of the Infraspinatous fossa. The lateral pectoral nerve ( lateral anterior thoracic) arises from the Lateral cord of the Brachial plexus, and through it from the fifth sixth and seventh The Pectoralis major (popularly known as pecs) is a thick fan-shaped muscle situated at the upper front ( Anterior) of the Chest wall The medial pectoral nerve ( medial anterior thoracic) arises from the Medial cord of the plexus and through it from the eighth cervical and first thoracic The musculocutaneous nerve arises from the Lateral cord of the Brachial plexus, opposite the lower border of the Pectoralis minor, its fibers being derived The Coracobrachialis is the smallest of the three muscles that attach to the Coracoid process of the Scapula. The brachialis ( brachialis anticus) is a Muscle in the upper Arm that flexes the elbow joint. In Human anatomy, the biceps brachii is a Muscle located on the upper Arm. The lateral antebrachial cutaneous nerve (or lateral cutaneous nerve of forearm) (branch of Musculocutaneous nerve, also sometimes spelled "antebrachial" The median nerve is a Nerve that runs down the Arm and Forearm. The upper subscapular ( short subscapular, superior subscapular) enters the upper part of the Subscapularis, and is frequently represented by two branches The Subscapularis is a large triangular muscle which fills the Subscapular fossa. The thoracodorsal nerve ( middle or long subscapular nerve) a branch of the Posterior cord of the Brachial plexus, derives its fibers from the The latissimus dorsi (plural latissimi dorsi is the large flat dorso-lateral muscle on the trunk posterior to the arm and partly covered by the Trapezius on its median The lower subscapular ( inferior subscapular) is a nerve which supplies the lower part of the Subscapularis, and ends in the Teres major; the latter muscle Teres major is a muscle of the Upper limb and one of six scapulohumeral muscles 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 The Teres minor is a narrow elongated muscle of the Rotator cuff. The superior lateral cutaneous nerve of arm (or superior lateral brachial cutaneous nerve) is the continuation of the posterior cord of the Axillary nerve, after it The radial nerve is a Nerve in the human body that supplies the Triceps brachii muscle of the arm as well as all 12 muscles in the Posterior osteofascial compartment The triceps brachii ( Latin for "three-headed" of the arm is the large muscle on the back of the human Upper limb. The supinator is a broad muscle curved around the upper third of the radius. The anconeus muscle is a small Muscle on the posterior aspect of the elbow joint An extensor muscle is any Muscle that opens a joint increasing the angle between components of a limb such as straightening the Knee or elbow and bending The forearm is the structure on the Upper limb, between the elbow and the Wrist. Brachioradialis is a Muscle of the Forearm that acts to flex the forearm at the Elbow. The posterior cutaneous nerve of arm ( internal cutaneous branch of musculospiral, posterior brachial cutaneous nerve) is a branch of the radial nerve that provides The medial pectoral nerve ( medial anterior thoracic) arises from the Medial cord of the plexus and through it from the eighth cervical and first thoracic The Pectoralis major (popularly known as pecs) is a thick fan-shaped muscle situated at the upper front ( Anterior) of the Chest wall The Pectoralis minor is a thin triangular muscle situated at the upper part of the Chest, beneath the Pectoralis major. The median nerve is a Nerve that runs down the Arm and Forearm. The medial brachial cutaneous nerve ( lesser internal cutaneous nerve; nerve of Wrisberg, medial cutaneous nerve of arm) is distributed to the skin on the In Anatomy, an arm is one of the Upper limbs of an animal The term arm can also be used for analogous structures such as one of the paired upper limbs The Medial Antebrachial Cutaneous Nerve ( internal cutaneous nerve, medial cutaneous nerve of forearm, also sometimes misspelled "antibrachial" arises from In Human anatomy, the ulnar nerve is a nerve which runs near the Ulna bone The flexor carpi ulnaris muscle (FCU is a muscle of the human forearm that acts to flex and adduct the hand In Human anatomy, the flexor digitorum profundus is a Muscle in the Forearm that flexes the Fingers It is considered to be an Extrinsic The hands ( med / lat: manus pl manūs are the two intricate prehensile multi- Fingered body parts normally located at the end of each arm of a

Superficial dissection of the right side of the neck, showing the carotid and subclavian arteries.	The axillary artery and its branches.	Cutaneous nerves of right upper extremity.	Diagram of segmental distribution of the cutaneous nerves of the right upper extremity.
The right sympathetic chain and its connections with the thoracic, abdominal, and pelvic plexuses.	Side of neck, showing chief surface markings.

See also

• Brachial plexus lesion
• Anesthesia of the brachial plexus

References

1. ^ Mnemonic at medicalmnemonics.com 18 2741
2. ^ t_20/12826113 at Dorland's Medical Dictionary
3. ^ t_20/12826075 at Dorland's Medical Dictionary
4. ^ t_20/12826025 at Dorland's Medical Dictionary
5. ^ d_26/12310223 at Dorland's Medical Dictionary
6. ^ d_26/12310244 at Dorland's Medical Dictionary

External links

• Norman/Georgetown lesson3brachialplexus
• Tutorial at Newcastle University