Spinal Cord

The spinal cord is a cylindrical mass of nerve tissue that extends from the caudal medulla. The marrow of an adult is about 45 cm long and occupies the upper two thirds of the spinal canal. During the early stages of spinal cord development occupies almost the entire spinal canal, but the rapid growth experienced spine then leads to the provision that has the adult. The lower end of the bone is called the terminal cone. The spinal cord is divided into 31 segments: 8 cervical, 12 thoracic or dorsal, 5 lumbar, 5 sacral and one coccygeal. nerves leave the spinal cord along entire length, the number of a couple for each spinal segment. The bone has two nodes, the cervical and lumbar. The cervical enlargement corresponds to the origin of the nerves that go to the upper limb, the fatness cough lumbar nerves that go to the lower member. structure The spinal cord consists of gray matter and white matter that adopt a fairly regular distribution. The white substance occupies the outside surrounding the gray matter, and consists of ascending and descending fibers supported by glia. When examining a cross section of the bone can be seen that the gray matter has an H-shaped arrangement The horizontal part of the corner H is called gray, and each of the ends called mast. Accordingly, two shafts and two ventral or dorsal horns earlier or later.the white substance is arranged in three columns or fiber strands, anterior or ventral or dorsal side and rear, extending from a level of the nervous system to another. Fibers extending from one place to another are grouped in bundles or tracts called fascicles. Several cracks running along the spinal cord. In the figure shows two of these cracks, the anterior or posterior or ventral and dorsal. The anterior fissure is deeper and is used to identify the front of the spinal cord. Role The gray matter of the spinal cord reflex center serves and is part of a distribution center for sensory and motor pathways. acts like The white substance high pulse conductive path to the brain and from this.