Which nerves provide innervation to the longissimus muscle?

The longissimus muscle is a part of the erector spinae group of muscles and plays a crucial role in the extension and lateral flexion of the vertebral column as well as in head and neck movements. It spans a significant portion of the spine, running from the lower back to the upper thoracic region and into the neck.

The correct innervation of the longissimus muscle is provided by lower cervical, thoracic, and lumbar spinal nerves. These spinal nerves arise from the spinal cord at different levels and correspond to the segments of the longissimus muscle. Specifically, the lower cervical nerves innervate the portions of the longissimus that are more superior, as these nerves supply the upper regions of the muscle located near the neck. The thoracic and lumbar spinal nerves innervate the middle and lower sections of the longissimus, which are located throughout the thoracic and lumbar regions.

This comprehensive range of spinal nerve innervation allows the longissimus muscle to effectively perform its functions across a wide area of the back and neck, highlighting the importance of both lower cervical and thoracic as well as lumbar spinal nerves in ensuring the muscle's operational integrity.