Cerebral peduncles: functions, structure and anatomy

the human brain It is such a complex organ that to function properly it must have the participation of a large number of parts and structures in its anatomy. Several of these parts of the brain are large and easy to distinguish with the naked eye, such as the frontal lobes, but others are very small and lie below these surface folds.

This is the case of the cerebral peduncles, small regions of the brain that, despite their size, are very important. Below you will be able to learn more about these anatomical structures.

What are the cerebral peduncles?

The human brain is roughly made up of two main types of “stuff”: Gray matter and the white matter. The first is the one that contains a higher concentration of neuronal somas "that is, of neuron" bodies, the area in which the nucleus of these cells is found), while In the areas with white matter, other anatomical areas of the neuron predominate: the axons, narrow and elongated elements that, when grouped in the form of bundles, form fibers. nervous.

The cerebral peduncles are two small cylindrical structures and white color They are made up of white matter. They are born from Brain stem, specifically above the pons, and reach the cerebral cortex projecting vertically.

Between the peduncles of the brain is the interpeduncular fossa, a space that acts as a physical separation between these two structures as if it were a kind of tunnel. Besides, the ventral and dorsal aspects of each peduncle are separated each other by a sheet of something that is not white matter, but something known as black substance.

They are not the same as the cerebellar peduncles

It is easy to believe that the cerebral peduncles are the same as the cerebellar peduncles, but this is not the case. These second structures have a similar function, since they also function as important neural pathways that collect information from various regions. However, both their location and the type of information that these neural signal pathways integrate are different.

Functions of the cerebral peduncles

The cerebral peduncles are fundamentally "highways" of nerve impulses that travel through the brain. Because they are made of white matter, this information passes through them quickly, as the myelin that covers the axons (and that gives these structures that white hue) makes these electrical signals go at great speed.

The main function of the cerebral peduncles, then, is to communicate two areas of the brain: he midbrain (located in the upper part of the brainstem) and the cerebral cortex. In fact, these nerve fiber ducts reach the division that is created between the two cerebral hemispheres.

In fact, the peduncles contain several pathways. One of them is the corticospinal, which, as its name indicates, communicates the cortex with the spinal cord, and the other is the corticopontine tract, which joins the crust with the Varolian bridge.

Since the brainstem is responsible for executing automatic and stereotypical actions that are useful or necessary for our survival, the role of the cerebral peduncles also has to do with this task.

Thus, the main functions of these bundles of nerve fibers are regulation of motor impulses and the transmission of reflex actions, two very useful mechanisms to keep us alive, since they allow you to react quickly to significant events (especially if they are dangerous or harmful).

Specifically, the peduncles have an important role in the reflex eye movements, necessary for them to function well, and in the coordination of these acts with other movements of the head and neck.

Specifically, these structures are involved in the reflex control of reflex movements. Normally this occurs when the orders from the motor cortex reach the cerebral peduncles, and from these they go to various nuclei of a structure known as the thalamus, located deep within the brain, in an area known as the diencephalon

Parts of this pair of structures

The cerebral peduncles receive connections from the cerebellum, the cerebral cortex, and the lower parts of the brainstem and spinal cord.

On the other hand, the cerebral peduncles are composed of several parts or sections. One of them is the tegmentum of the midbrain, which is followed by the cerebral crus, and the other region is called the pretectum. The tectum extends beyond the brainstem, reaching as far as the cortex of the brain.

The complexity of the different components of the peduncles has to do with the fact that they are located in an area of ​​the central nervous system in which all kinds of functions of control and coordination of specialized actions are carried out and created by millions of years of evolution and selection natural. In little space, the brainstem has tiny areas responsible for carrying out actions as vital as the regulation of the heartbeat or the control of body temperature.