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

Internally, the medulla spinalis is made of substantia grisea et alba just like other parts of the systema nervosum centrale. Externally, it contains an anterolateral and posterolateral surface, which feature a number of grooves known as fissures and sulci.The fissura mediana anterior is a deep groove along the anterior length of the medulla spinalis that incompletely divides it into symmetrical halves. The a. spinalis anterior travels within this fissure and supplies the central spinal region. Lateral to the fissura mediana anterior is a bilateral shallow groove known as the sulcus anterolateralis. The radiculae radicis anterioris nervi spinales emerge at this point. The sulcus medianus posterior extends along the posterior midline of the medullary spinalis. On either side of the sulcus medianus posterior are the sulci posterolaterales, from which the radiculae radicis posterioris nervi spinales emerge on either side. The radiculae radicis posterioris join with the radiculae radicis anterioris to form the radix anterior and ganglion spinale. The union of these radix leads to the formation of the truncus nervi spinalis.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 sulcus intermedius posterior.