Health Sciences 2300A/B Lecture Notes - Lecture 6: Lumbar Plexus, Cervical Plexus, Median Nerve

• School: Western University
• Department: Health Sciences
• Course: Health Sciences 2300A/B
• Professor: Christopher William James Melling

Document Summary

Redundancy in the innervation of structures allows maintenance of innervation if there is damage to the plexus and to maintain multiple levels of control. Eg. multiple ways back to the spinal cord from the median nerve. Brachial plexus: median nerve innervates all the muscles in the finger that allow them to move back & forth. Muscle groups: muscles of the pectoral girdle/shoulder joint: affected by anterior. & posterior muscles: muscles that move the humerus, axial, scapular. Muscles that enforce the shoulder joint: rotator cuff muscles (google this, only one ligament supports the shoulder joint directly. Supraspinatus muscle: above the spine and comes off the supraspinous fossa, attaches to the humerus via the greater tubercle, causes abduction of the humerus (lifts the humerus, innervated by suprascapular nerve. Infraspinatus muscle: below the spine, cuffs arounds and attaches to the greater tubercle, innervated by suprascapular nerve.