Lecture on Anatomy and Neurology of the Cervical Spine

Introduction

• Importance of understanding cervical spine anatomy to appreciate spine pathologies.
• Cervical spine has a normal lordotic curve.
• Designed to handle extension and compression loads.

Cervical Spine Anatomy

• Vertebrae arranged in a way that favors extension and compression.
• Less able to handle straight axial loads.
• Possible injuries include catastrophic ones from axial loaded flexed spine.

Facet Joints

• Prone to overuse degeneration.
• Connected to conditions like spondylosis and instability.
• Nerve roots exit bilaterally from the spinal cord.
• Blood supply through vertebral foramina.

Nerve Root Exits

• In cervical spine, nerve root exits above the vertebra they're named after.
• Changes occur after the 7th cervical vertebra due to eight nerve roots and seven vertebrae.
• Discs start below C2.

Anatomy Specifics

• Occipital bone rests on C1.
• Atlanto-occipital joint allows limited flexion and extension.
• Atlanto-axial joint allows rotation.
• Important for facet joints to refer pain as they are synovial.

Neurology

• Injury above C4 can lead to respiratory issues.
• Myotomes and dermatomes are important for identifying spinal nerve issues.

Vertebral Anatomy

• Vertebral arch protects spinal cord.
• Spinous processes for muscle and ligament attachment.
• Longitudinal ligaments limit flexion and extension.

Brachial Plexus

• Network of nerves from cervical spine (C5 to T1).
• Composed of roots, trunks, cords, and branches.
• Supplies muscles of the upper extremity.

Structure

• Roots form trunks (superior, middle, inferior).
• Trunks form cords (lateral, posterior, medial).
• Cords lead to peripheral nerves supplying muscles.

Peripheral Nerves

• Musculocutaneous nerve for biceps.
• Median nerve for wrist flexors.
• Ulnar nerve for medial elbow and hand muscles.
• Posterior cord for axillary and radial nerves.

Additional Nerves

• Long thoracic nerve supplies serratus anterior.
• Suprascapular nerve affects supraspinatus and trapezius.

Nerve Root and Muscle Connections

• Focus on anterior and posterior divisions of brachial plexus.
• Musculocutaneous, median, and ulnar nerves supply anterior compartment muscles.
• Radial nerve for posterior compartment muscles (triceps, wrist extensors).

Dermatome and Myotome Overview

• C5-T1 dermatomes and myotomes detailed.
• Important for upper quarter screening.
• Quick methods for remembering key points.

Conclusion

• Important foundation for understanding pathologies and preparing for neurologic exams.

These notes provide a comprehensive overview of the cervical spine anatomy and neurology, with a focus on the brachial plexus and its implications for muscle and nerve function.