Spinal Cord: Structure, Function & Diseases

The significance of the spinal cord becomes clear to most people predominantly when it comes to specific diseases or paralysis symptoms. Otherwise, the spinal cord is a very complex and intricately structured system, which, however, is hardly noticeable in a healthy state.

What is spinal cord?

When defining the spinal cord, various terms are used such as the medulla spinalis or the myelon. Basically, the colloquial term spinal cord refers to a part of the nervous system. In contrast to other regions of the central nervous system, the spinal cord, which is about 40 cm long, is concentrated in an elongated cavity within the spinal column. The individual openings in the vertebral bodies, when combined, provide a passageway for the spinal cord.

Antomy and structure

The morphology of the spinal cord is exceedingly fine and is based on a collection of nerve fibers and so-called perikarya. The perikarya are anatomical components of the ascending and descending nerve cells. The spinal cord comprises several sections, which include the cervical, thoracic, lumbar and sacral, depending on their location. In contrast to the spinal cord in the cervical and lumbar regions, the spinal cord is much narrower at the level of the lungs and neck. In the lower regions toward the buttocks, there is a greater density of neurons. When viewing the spinal cord, an anterior medullary cord, a lateral medullary cord, and a posterior medullary cord can be seen. In addition, a double covering of hard and soft media protects the spinal cord. These layers are called the spinal cord cuticle. The morphology of these cuticles is similar to that of the meninges. When the spinal cord is cut transversely, the white and gray medullary substances are conspicuous, which are composed of different physiologically relevant structures. In an overview diagram, the cross-section of a spinal cord is compared to a butterfly with its wings spread.

Functions and tasks

The spinal cord works closely with the brain and provides the link between this “control center” and all organs. The skin and muscles are also subject to control by the brain via the spinal cord. In addition, the most diverse stimuli can be received via the spinal cord through the peripheral nervous system (this runs along the outer areas of the body) and fed to the brain. The spinal cord is also responsible for tasks such as monitoring motor functions and body movements, coordinating all functional processes in the organism and processing environmental stimuli. More extensive functions of the spinal cord also have to do with feeling, speech and thinking. Through the spinal nerves, stimuli received from the outside are both absorbed by the spinal cord through the gray and white medullary substance and transmitted to the brain and vice versa. In the spinal cord, in addition to the aforementioned nerve cells, there are also the neurotransmitters that are essential for the transmission of stimuli, which work on a biochemical basis between the processes of the nerve cells.

Diseases

A large number of diseases relate exclusively to the spinal cord. More diseases involve the spinal cord to some degree. This fact applies, for example, to multiple sclerosis, meningitis and epilepsy. If the spinal cord suffers from spondylolysis or Paget’s disease, or if other destruction of the spinal cord occurs, the consequences may be catastrophic. In all diseases in which the spinal cord is affected in some way, disturbances of the ability to perceive, of speech, of the ability to move, of the execution of simple involuntary reflexes, and of thinking occur in varying degrees of severity. A plethora of diseases of the spinal cord are caused by mechanical effects due to injuries. These are impairments such as paraplegia in varying degrees of severity such as tetraparesis, paraparesis, and paraparalysis. Other disease-specific deficits in the spinal cord include myelopathy, blood supply disorders, inflammation of the spinal cord, and constriction of this system by a herniated disc. Myelopathy involves damage that has occurred to the spinal cord in the cervical spine. The spinal cord is compressed by an increase in the volume of bony substances.Myelitis is an inflammatory process in the spinal cord, which is primarily triggered by microorganisms. If the spinal cord membranes are affected by these inflammatory processes, the term meningomyelitis is used.

Typical and common diseases

  • Syringomyelia
  • Spinal injury (spinal trauma)
  • Amyotrophic lateral sclerosis
  • Paraplegia
  • Multiple sclerosis
  • Leukemia