Anatomy & Organs

Central Canal – Structure, Function & Diseases

Central channel

The central canal, or canalis centralis , is a tubular structure that runs through the spinal cord and extends into the medulla oblongata . Errors in embryonic development can result in neural tube defects ; an example of this is anencephaly . In addition, tumors can form from the ependyma of the central canal .

What is the central channel?

The central canal (canalis centralis) is an anatomical structure that is part of the spinal cord and extends into the elongated spinal cord (medulla oblongata). There the central canal is clearly visible as a protruding tube. It belongs to the inner liquor space, which also includes the cerebral ventricles .

The central canal is located in the gray matter of the spinal cord. It owes its name to its greyish colour, which separates the gray matter from the white matter . The latter mainly contains isolated nerve fibers, while the gray matter consists mainly of nerve cell bodies. These tissue designations apply to both the spinal cord and the brain . Together, these two anatomical structures form the central nervous system ; the medulla oblongata, which contains the uppermost part of the central canal, belongs to the brain and represents the transition from the spinal cord to the brainstem .

Anatomy & Structure

The interior of the central canal is filled with a fluid known as cerebrospinal fluid . The substance is also found in the inner and outer cerebrospinal fluid spaces of the brain and consists mainly of water. There are only a few cells and proteins in the liquor cerebrospinalis.

Proteins found in CSF include albumin (human albumin) and beta trace protein. Most of the cells in the cerebrospinal fluid are white blood cells or leukocytes , which are part of the human immune system and are also found in the blood . Glial cells are responsible for the production of the cerebrospinal fluid and combine in clusters to form the choroid plexus .

At the head there is a connection between the central canal and the cerebral ventricles, which are among the inner cerebrospinal fluid spaces of the brain . In some people, the central canal merges into the terminal ventricle at the lower end , but this thickening of the canal is of no functional importance and usually regresses during embryonic development. The Ventriculus terminalis is merely an evolutionary remnant (rudiment).

Function & Tasks

Inside, a single layer of ependyma, which consists of glial cells, stretches over the walls of the central canal. In biology, they belong to the subtype of neuroglial cells. On the outside of the central canal is the substantia gelatinosa centralis, which contains numerous glial cells.

On the outside of their membrane, the ependymal cells carry two functionally important structures: the microvilli and the kinocilia. The microvilli are protrusions from the cell and reach a length of 1-4 µm and an average width of 0.08 µm. They serve to increase the surface area of ​​the ependymal cells. The kinocilia are also protuberances from the cell, but they are slightly larger and can be 10 µm long and 0.25 µm wide. With the help of the kinocilia, the glial cells can move the cerebrospinal fluid and thus actively contribute to its transport. The ependyma also contains glycoproteins that are important for long-term memory function.

The central canal arises from the hollow interior (lumen) of the neural tube, which forms during the first four weeks of human embryonic development. The two openings of the neural tube at the top and bottom then close, and disruption can lead to the development of neural tube defects .

Diseases

Neural tube defects are pathological conditions that form during embryonic development when the neural tube does not close properly. A severe form of neural tube defects is anencephaly ; even in the case of children who are born alive, the survival time is usually only a few hours, even if intensive medical care is ensured.

The reason for this lies in the missing parts of the brain that do not develop in the context of anencephaly. Anencephaly is therefore an indication for termination of pregnancy , but the mother of the child may choose to carry the child to term. Psychological support for the mother is often useful in order to process the process emotionally. Physically, anencephaly in the unborn child does not usually pose a physical threat to the pregnant woman.

In addition, tumors known as ependymomas can develop from the ependyma . The neoplasms arise from uncontrolled cell growth in the tissue layer and often appear as elongated structures resembling the shape of a pencil. The ependymoma is surrounded by a capsule. Which treatment options are possible depends on the individual case; In principle, surgical interventions and radiation therapy are the main options to combat the tumour.

Inflammation of the ependyma is also possible. Such ependymitis can occur as a result of an infectious disease; possible causes include syphilis , a sexually transmitted disease with possible neurological disorders, and toxoplasmosis . The latter is an infectious disease that goes back to the parasite infestation with Toxoplasma gondii. The disease mainly affects cats, but can also spread to humans. In a healthy person, the majority of those affected will not manifest any visible or noticeable symptoms. However, other inflammations can also occur, for example in the meninges or in thelungs.

Website | + posts

Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.