Cervical part of spinal cord

The cervical part of spinal cord extends from the base of skull / foramen magnum. It continues downwards as the thoracic, lumbar and sacral regions; each having distinct morphological features.

Like all other regions, the cervical part of spinal cord consists of a central butterfly shaped gray matter with anterior (motor) and posterior (sensory) gray columns or horns. The cervical part of spinal cord is distinct from other regions, as it has more gray matter (hence, bigger anterior and posterior horns) due to additional neurons that are required to innervate the upper limb musculature.

Within the anterior gray horn, the cells can be grouped into medial, central and lateral groups. The medial group of cells innervates structures closer to midline including neck muscles, whereas the lateral group innervates structures further away from the midline, such as the upper limb musculature, via brachial plexus. The central group lies in the middle and comprises of spinal accessory nucleus (to innervate trapezius and sternocleidomastoid) and phrenic nucleus (to innervate diaphragm).

The posterior gray horn contains two distinct groups of nuclei, which extend throughout the length of the spinal cord. These include substantia gelatinosa group (receiving pain and temperature sensations) and nucleus proprius group (receiving sensory information of proprioception, vibration, and 2-point discrimination). In addition, the beginning of dorsal nucleus of Clarke can also be seen in the C8 segment as the nucleus extends down into the thoracic region of spinal cord. Clarke’s nucleus receives proprioceptive information that is relayed to the cerebellum.

There is no lateral gray horn in the cervical part of spinal cord.

The gray matter on both sides–right and left–are interconnected by a gray commissure that contains a central canal.

The gray matter is surrounded by bundles of white matter fibers or tracts. These include the anterior, posterior and lateral white columns (or funiculi).

The anterior white column (a.k.a. anterior funiculus) contains sensory and motor tracts, such as, anterior spinothalamic, anterior corticospinal, tectospinal, vestibulospinal and pontine reticulospinal tracts.

The lateral white column (a.k.a. lateral funiculus) also contains a mixture of sensory and motor tracts, including anterior and posterior spinocerebellar, lateral spinothalamic, lateral corticospinal, lateral reticulospinal and rubrospinal tracts.

The cervical part of spinal cord being the superior-most, contains both fasciculus gracilis and fasciculus cuneatus in the posterior or dorsal white column. The fasciculus gracilis carries information of vibration, proprioception and 2-point discrimination from the lower body (T6 spinal segment and below), while the fasciculus cuneatus carries the same information from the upper body (T6 spinal segment and above).