Atlas of plant and animal histology

The main anatomical regions of the spinal cord can be observed in this figure, which is a transverse section of rat spinal cord after a general staining. The central canal is located in the medial and central within the spinal cord. The cerebrospinal fluid flows through this canal, which is limited by the ependyma. The gray matter surrounds the central canal. Most somata of the spinal cord neurons localize in the gray matter, which can be subdivided into further regions. The gray matter has a shape that resembles the open wings of a butterfly, although in other species it may have a more rounded shape or even be flattened, as observed in lampreys and hagfish (Figure 1). The white matter wraps the gray matter and is largely made of axons coming from the encephalon, sensory neurons of the peripheral nervous system, and intraspinal neurons known as propriospinal neurons. Axons originated in the same source are usually packaged in bundles or funiculi located in specific positions along the white matter.