Neuroscience | Spinal Cord Structure

The spinal cord (medulla spinalis) is an important part of the central nervous system. The spinal cord conducts stimuli and establishes connections to the brain and the rest of the body. The spinal cord is a long, tubular structure that contains nerve cells in addition to nerve fibers.

31 pairs of spinal nerves originate from the spinal cord on both sides. These connect the different parts of the body to the spinal cord and the brain. The spinal cord and spinal nerves play a role in the body’s very rapid responses to changes in the environment through reflexes or involuntary responses. A circuit has then taken place from the body via the nerve fibers in the spinal cord itself. The stimuli did not go through the brain. When reactions become conscious, a circuit has taken place in the brain. Those reactions can therefore be influenced. Visit ‘CTSI‘  for more details about the spine.

Spinal cord location
The spinal cord runs from the base of the brain to the lower part of the back. It lies within the spine, which forms a sturdy shell. The spine is held in place by strong ligaments and muscles. The spinal cord is therefore usually very well protected. The growth of the spinal cord is completed earlier than that of the spine. As a result, the spinal cord does not completely fill the spinal canal. Low in the spinal canal is only cerebrospinal fluid with nerves, the so-called horsetail (cauda equina). The spinal cord in adults is about 40 to 45 centimeters long with a diameter of about 1 centimeter.

Spinal cord structure
The spinal cord is a long tube in the center of the vertebrae made up of nerve cells. The spinal cord is covered on the outside with three membranes, the spinal cord membranes. Below the three membranes are described from the outside to the inside.

  • The hard, tough dura mater.
  • The thin arachnoid (spider web).
  • The thin, transparent pia mater.

Relationship of the spinal cord to other parts of the nervous system
The spinal cord is closely related to many important structures of the nervous system. At the top, there is a connection with the extended marrow (medulla oblongata), the lower part of the brain. The spinal cord membranes line the entire length of the spinal cord, and cerebral fluid flows through channels around the spinal cord and brain. The spinal cord is also connected to brain cavities. 31 pairs of spinal nerves originate from the spinal cord. These nerves conduct information to and from the spinal cord to different parts of the body.

Spinal cord structure abnormalities
The structure of the spinal cord can show various abnormalities. These abnormalities are either present from birth or arise later in life. Examples of birth defects are spina bifida and meningo (myelo) kele. In the latter condition, the spinal cord membranes and/or spinal cord bulge, because the vertebrae are not completely closed. An abnormality that develops later in life is, for example, syringomyelia. It is a condition in which cavities in the spinal cord have altered the internal structure of the spinal cord. A change in the structure and functioning of the spinal cord can also be caused by (benign and malignant) tumors of the spinal cord.