Callous body: what is it and what is it for?

You have just entered medical school and are faced with the most anticipated (and also the most feared) subject in the entire basic cycle: anatomy! In the 1st period, you felt a little difficulty in decorating that infinity of names and structures of the skeletal, muscular and also the articular apparatus. But now you have started the 2nd period and with it came neuroanatomy. That infinite number of names that you had to memorize in the 1st period multiplied by 100. In addition, the physiology of those studied structures was added and, together, they made a knot in all the grooves and turns of your brain.

In the midst of so much study on human anatomy and physiology, there comes a time when, for sure, you ask yourself: what do I have to know that for? Certainly, most medical students, upon entering college and starting to study the first subjects of the basic cycle, have already questioned themselves about this. These first two years are called the basic cycle precisely for the reason that they are the initial periods of a course, in which the student learns all the content that is recognized as fundamental for the understanding of the other cycles of the college. It is he who will provide the basis for learning the subjects to come. Therefore, it is a fundamental period in your academic life, when you cannot miss any details. At the end of this article,


Within our cranial box, we have some structures, including the telencephalon. The telencephalon comprises two main hemispheres, the right, the left and, between them, there is a central part. These two hemispheres (right and left) are not completely separated by a fissure called the longitudinal fissure of the brain. The floor of the longitudinal fissure is composed of a bundle of fibers, also called the corpus callosum, which is the only form of connection between these two hemispheres that constitute the telencephalon.

The corpus callosum, as already commented in the article, is a structure formed by the union of several myelinated fibers, which will intersect in the sagittal plane of the brain and penetrate the medullary white center of the brain, thus making the union of the two cerebral hemispheres. It is estimated that the corpus callosum is formed by about 200 to 250 million axon projections.

We can divide the corpus callosum into trunk , knee, splenium and rostrumof the corpus callosum. The trunk of the corpus callosum, also known as the body, corresponds to the upper face of the structure. In it, we were able to observe a longitudinal groove. The knee of the corpus callosum is nothing more than the anterior end of the corpus callosum. It is your most finely tuned region. The corpus callosum splenium is a posterior dilation of the corpus callosum trunk. This structure will undergo a flexion in its most anterior part (going towards the brain base) and will form the knee of the corpus callosum. The fornix is ​​another important structure, which is associated with the corpus callosum. It is a set of fibers, organized in the form of a bundle and composed of two halves: one lateral and one medial. These bundles are arranged symmetrically and the halves are joined together by means of a septum called a pellucid septum.

Embryology and histology:

The formation of the corpus callosum begins, first, around the twelfth week of gestation, and is fully developed when the fetus reaches the eighteenth week of gestation, and may even evolve until the twenty-second week. The tissue that originates the corpus callosum is the embryonic leaflet ectoderm, tissue, which you are probably familiar with, due to its important function within embryology. Its basic composition is axons of neurons, which are covered by myelin, and form fimbrias that will cross the entire median sagittal plane.

Functions of the corpus callosum:

This anatomical structure plays an important role in the functioning of our organism and in the organization of information that reaches the cerebral hemispheres. Among the most important functions, we can highlight as the main one the fact that the corpus callosum will facilitate the communication between these two hemispheres of the telencephalon, as previously discussed.

In addition to these functions, it is important to remember that the brain has a contralateral organization. But what is this? As already mentioned, we have two cerebral hemispheres. The nervous system of human beings cross-connects with brain tissue. This means that the right side of the cerebral hemisphere is responsible for controlling the left side of our body, while the left side of the cerebral hemisphere is responsible for controlling the right side of the human body, and this we call contralateral control. Scientists have also shown that both brain hemispheres have somewhat distinct and independent activities and functions. As for example, the right side manifests itself through emotion and expresses it through that individual’s visual language,


The corpus callosum, like any structure of the human body, can undergo important genetic changes, which almost completely impairs its functioning. Individuals who come to present this type of congenital anomaly, will have intense difficulty in communicating, and with that we will find aphasias, dyslalia or dysphasias in the physical examination of the patient. The most common and known genetic alteration of the corpus callosum is corpus callosum agenesis. It can be classified into 3 main types: in type 1, we classify changes where the corpus callosum is absent in the brain of these patients. Type 2 is a partial alteration of this corpus callosum, and is also popularly known as corpus callosum hypogenesis. In type 3, the patient has his corpus callosum properly formed,


The corpus callosum is an anatomical structure extremely important for the proper functioning of our body and the organization of our senses, such as hearing, speech and even vision. Individuals who have genetic abnormalities in this segment have difficulties in the functioning of these areas, and may have flaws in speech and vision. Therefore, the corpus callosum is not just a structure that exists to confuse our understanding. It has an essential function, therefore, it must be very well studied and understood, so that we can identify, during our medical practice, which individuals have symptoms suggestive of pathologies in this structure, and may then be able to treat them correctly.


by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

Leave a Comment