Spinal reticular process

At a glance

English

Spinal reticular process

Latin (TA2)

Processus reticularis spinalis

System

Nerve

Region

Whole body

Side

Single, on the midline

About the spinal reticular process

In a cross-section of the spinal cord, the lateral edge of the grey matter is usually sharp. Next to the base, or neck, of the posterior horn, however, the boundary breaks up: thin bands of grey matter reach out into the lateral funiculus and enclose small bundles of white matter between them. This lattice is the reticular process, also called the reticular formation of the spinal cord.

It is best developed in the cervical segments and becomes much less obvious in the thoracic and lumbar cord. It lies in the angle between the posterior horn and the lateral horn or intermediate zone, immediately medial to the long tracts of the lateral funiculus. Upwards it is continuous with the reticular formation of the medulla, of which it can be seen as the lowest part.

The nerve cells scattered among its strands are mostly interneurons and projection neurons that take part in reflex and autonomic circuits and pass information towards the brainstem. In sections stained for myelin it gives the outer border of the posterior horn neck a frayed look, which helps in recognising cervical levels. Disease affecting the central grey matter or the adjacent lateral funiculus, such as a widening central cavity in syringomyelia, may involve it, but it does not produce a recognisable clinical sign on its own.

Course and supply

Supplies

Holds scattered interneurons and projection neurons linking spinal reflex and autonomic circuits with the brainstem reticular formation.

Blood supply

Lies in the deep part of the cord near the border between the territory of the sulcal branches of the anterior spinal artery and the penetrating branches from the arterial vasocorona.