Puente de Varolio: structures, characteristics and functions

Puente de Varolio: structures

The Varoli bridge, also known as the ring bump or brain stem bridge, is one of the most important parts of the brain. In fact, a small injury to this structure could result in sudden death or entry into a coma.

The reason for the importance of the Varolio Bridge is that it is one of the largest portions of a structure known as the brain stem, which is responsible, among other things, for maintaining automatic mechanisms that keep us alive.

We will now look at the anatomy, parts and functions of the ring bump, as well as the health problems that can be triggered if alterations in behaviour occur due to injury or illness.

What is the Pont de Varolio?

The brainstem bridge is the largest part of the brain stem , which is why it is also called the ring bump. It is located between the two other major anatomical structures in this portion of the brain. The upper part of the brain borders the midbrain, while the lower edge of the brain is in contact with the spinal cord.

The boundary separating the ring-shaped bulb from the spinal bulb is the protruberancial sulcus, while its border with the midbrain is the pontomesoencephalic sulcus.

Anatomy of the Annular Lump

Like any other region of the central nervous system, the lump is composed primarily of neurons and glial cells. However, in this region of the brain , the bundles of axons that run vertically from the brain to the spinal cord to the brain and back again are particularly important. In other words, the ring bump acts partly as a communication pathway between two large portions of the central nervous system.

However, the pons also contain bundles of neurons that are distributed sideways, forming the beginnings of the medial cerebellar peduncles, which are two of the areas through which the brain stem connects to the cerebellum.

Another of the most remarkable anatomical features of the pons is that its front face, the one closest to our face, is convex, bulging outwards , which makes it stand out from the other two main structures of the brain stem.

Inside the Varolio bridge is the basilar groove , a small space through which it crosses the basilar artery, one of the main responsible for keeping cells in large areas of the brain alive.

In addition, the lump forms the beginning of the trigeminal nerve, one of the most important cranial pairs.

Parts of the trunk brain bridge

The ring bump is formed by a set of nuclei , consisting of groups of associated neurons that perform similar functions. They are as follows.

Somatic motor core abductor

A nucleus of neurons linked to the cranial nerve pair known as the abducens nerve, which is responsible for the movement of the abducted eye.

Special trigeminal motor core

The functions of this nucleus have to do with the trigeminal nerve, and basically consist of visceral movements.

Special facial motor core

Like the previous one, this one takes care of certain visceral movements.

Upper salivary core

The functions of this core are vegetative, and therefore automatic.

Its functions

The functions of the Varolio Bridge are diverse, although almost all are of great importance for survival.

1. Communication link

The ring bump bridges the gap between groups of neurons that would otherwise be cut off from each other. It allows information to flow from inside the skull to the outside and vice versa.

2. Motor coordination

The Varolio bridge works together with the cerebellum and other structures , such as the basal ganglia, to allow automatic and unconscious coordination of muscle groups. This makes it possible for us to keep our balance in an upright position, for example.

  • You may be interested in: “Human cerebellum: its parts and functions”

3. Homeostatic regulation

The ring bump plays an essential role in functions such as temperature regulation and other basic physiological processes , such as the heartbeat.

Regulation of consciousness

This region of the brain stem is crossed by reticular formation, and for that reason it plays a role in the regulation of states of consciousness. It intervenes in the circadian cycles of sleep and wakefulness, and also makes consciousness itself possible.

Injuries and associated diseases

The destruction or alteration of the normal functioning of the pons de Varolio has very serious consequences , as it affects very basic processes necessary to stay alive.

This is because a failure in this region of the brain can cause not enough blood or oxygen to reach the brain , leading to death by hypoxia.

The diseases that can affect this structure are several, but highlight Alzheimer’s disease and Parkinson’s disease , since both damage broad regions of the central nervous system and prevent the normal functioning of the networks of neurons.

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