It may be fixed by two ways
A. Prefixed: When C4 root joins with C5. Here C4 is large T2 is often absent.
B. Postfixed: When T2 root joins with T1. Here C4 root is absent. The contribution by T1 is large.
Situation: Roots of brachial plexus emerge between the scalenus anterior and scalenus medius muscles.
- Trunks appear in the lower part of Posterior triangle of neck
- Division lie behind the clavicle.
- Anterior divisions supply all the muscles present on the ventral part of thorax and upper limb.
Posterior divisions supply the muscles present on dorsal part of thorax and upper limb.
3. The cords are present in axilla. The names of the cords are in the relation with the second part of axillary artery. The cords give branches around 3rd part of axillary artery.
- Supra clavicular part: The roots and trunks of the brachial plexus lie above clavicle.
- Retroclavicular part: The divisions of brachial plexus lie behind the clavicle.
- Infra clavicular part: The cords and branches of cords lie below the clavicle.
Branches: A. The nerves arising from roots supply the muscles which bring protraction and retraction of shoulder girdle i.e
- Nerve to rhomboids ( dorsal scapular nerve C5)
- Nerve to serratus anterior ( long thoracic C5,C6 & C7)
B.Trunks: a. Suprascapular nerve(C5, C6) supplies
- Shoulder joint
- Acromioclavicular joint
b. Nerve to subclavius ( C5, C6) supplies subclavius muscle.
C. Cords: Following are the branches from respective cords.
a. Lateral : Laila love majnu ( 🗝keyword)
- Lateral pectoral nerve
- Lateral root of median nerve
- Musculo cutaneous nerve
- Medial pectoral
- Medial root of median nerve
- Medial cutaneous nerve of arm
- Medial cutaneous nerve of forearm
- Ulnar nerve
- Upper Subscapular
- Lower Subscapular
- Nerve to latissimus dorsi
- Axillary nerve
- Radial nerv
- Horner‘s syndorme: Its is due to involvement of sympathetic nerve, which is contributed by T1 through white rami communication. It usually occurs due to injury at the root of brachial plexus.
- Erbs paralysis: Injury to upper trunk usually at the Erb’s point causes Erb’s paralysis.
- Klumpke’s paralysis: Injury to the lower trunk of brachial plexus.
- Winging of scapula: Injury to the nerve to serratus anterior
- Claw hand: Injury to the ulnar nerve.
- What are the symptoms of brachial plexus injury?
ANS: The most common symptoms of brachial plexus include,
- Weakness or Numbness
- Loss of sensation
- Loss of movement