Upper limb
Trunks of brachial plexus (Superior, middle, inferior)
Trunci plexus brachialis (superior, medius, inferior)
- Origin
- Formed in the neck: Superior (C5–C6), Middle (C7), and Inferior (C8–T1) trunks
- Insertion
- Traverse the interscalene triangle above the first rib and divide into anterior and posterior divisions behind the clavicle
- Function
- Primary conduit distributing all motor and sensory fibers to the upper extremity and shoulder girdle
- Innervation
- Complete sensorimotor supply to the upper limb
- Movement & chain
- Pass between anterior and middle scalene muscles, susceptible to stretch on lateral neck traction
- Palpation
- Palpable in the posterior triangle of the neck / greater supraclavicular fossa
- Clinical
- Erb-Duchenne palsy (upper trunk C5–C6: 'waiter's tip' posture), Klumpke palsy (lower trunk C8–T1: intrinsic claw hand, Horner syndrome), traction injuries in motorcycle accidents
- Segmental innervation
- C5–T1 spinal segments
- In clinical practice
- Target site for interscalene and supraclavicular regional anesthesia blocks in shoulder/arm orthopedics
- Region in the model
- Upper limb
Related structures
- Divisions of brachial plexus (Anterior and posterior)
- Cords of brachial plexus (Lateral, medial, posterior)
- Subclavian artery