The brachial plexus is a major somatic nerve network supplying the upper limb. It is formed in the neck by the union of the anterior rami of spinal nerves C5-T1.
Description
The brachial plexus originates in the neck, with its roots passing through the gap between the anterior and middle scalene muscles with the subclavian artery. It then extends laterally and inferiorly over the first rib to enter the axilla.
It can be broken down into sections, similar to that of a tree.
- Roots
- Trunks
- Divisions
- Cords
- Terminal branches
The roots are formed from the anterior rami of C5-T1 and sympathetic fibers received from the gray rami of the middle and inferior cervical ganglia.
The roots then unite in the posterior triangle of the neck to form three trunks:
- Superior trunk: formed by the union of C5 and C6 roots
- Middle trunk: a continuation of C7 root
- Inferior trunk: formed by the union of C8 and T1 roots
Each of the three trunks then