Spinal cord: Cross section (External morphology) (English)

Internally, the spinal cord is made of gray and white matter just like other parts of the central nervous system. Externally, it contains an anterolateral and posterolateral surface, which feature a number of grooves known as fissures and sulci.The anterior median fissure is a deep groove along the anterior length of the spinal cord that incompletely divides it into symmetrical halves. The anterior spinal artery travels within this fissure and supplies the central spinal region. Lateral to the anterior median fissure is a bilateral shallow groove known as the anterolateral sulcus. The anterior rootlets of the spinal nerves emerge at this point. The posterior median sulcus extends along the posterior midline of the spinal cord. On either side of the posterior median sulcus are the posterolateral sulci, from which the posterior rootlets of the spinal nerves emerge on either side. The posterior rootlets join with the anterior rootlets to form the anterior root and posterior root ganglion. The union of these roots leads to the formation of the spinal nerve trunk.In between the posterior median and posterlateral sulci is another bilateral sulcus which is only present at the cervical and upper thoracic levels, known as the posterior intermediate sulcus.