Hindbrain, structure and functions

We divide the brain into different parts to try to better understand its functionality and development. One of them is the hindbrain, a region that comes from the caudal primary embryonic vesicle.

When we talk about rhombencephalon, we are referring to the hindbrain.. It is the structure that throughout its development will give rise to different substructures, responsible for carrying out different essential functions for the organism.

Through this text We will show you what the structure is, how the differentiation process occurs and the functions of this incredible respite center. Let’s begin the exploration!

Hindbrain differentiation

To begin, we must understand the origin of the hindbrain. And for this, it is important to clarify what differentiation is. According to Bears Connors and Paradiso, authors of the book Neuroscience. brain scan It is a process in which structures become more complex and functionally specialized.

The first step in brain differentiation is the development of three thickenings called primary vesicles of the neural tube. originating at the rostral end.

The most rostral part of the primary vesicles is the forebrain or forebrain; The vesicle located behind the forebrain is called the mesencephalon or midbrain, and The most caudal part of the vesicles would be the rhombencephalon or posterior brain, which in turn connects with the caudal part of the neural tube.

So, The hindbrain is formed during embryonic development. It does so through transverse segmentations called rhombomeres, compartments that allow the creation of cell groups that will develop differently; In addition, they will process different functions.

However, in the vesicle stage, the rostral hindbrain in cross section is tube-shaped. Subsequently, the rhombic lip or tissue of the dorsolateral wall of the tube grows in a rostral and medial direction until it fuses with the opposite side. Furthermore, the resulting fold grows forming the cerebellum. Additionally, the ventral wall of the tube dilates to form the bridge or bulge.

Besides, In the differentiation of the caudal half of the hindbrain in the medulla oblongata, changes occur, but less accentuated. On the one hand, the walls dilate and leave only the roof covered by non-neuronal ependymal cells. And on the other hand, white matter systems are present along the ventral surface of each side of the medulla oblongata or medulla oblongata.

Finally, As for the hole occupied by the cerebrospinal fluid, it will become the fourth ventricle, which will continue with the cerebral aqueduct of the midbrain.

Parts of the rhombencephalon

The hindbrain is differentiated into the following three essential structures:

1. Cerebellum

It joins the brain stem at the pons, and is a fundamental movement control center for our body. Derived from the rostral portion.

The cerebellum is essential for our life, since it is responsible for regulating movement and controlling balance. Thanks to it we can coordinate our march and maintain our posture. This structure controls muscle tone and voluntary muscle activity.

The evidence collected by different investigations has also indicated that this structure, specifically its posterior lobe, It can intervene in the control of cognitive and affective functions. Lesions of this lobe result in cerebellar cognitive affective syndrome, whose distinctive characteristics are: deficits in executive function, visual spatial processing, linguistic skills, and affect regulation.

2. Varoli Bridge

This is a part of the rostral hindbrain. It is located anteriorly with respect to the cerebellum and the fourth ventricle. This structure is strongly associated with many autonomic functions such as breathing, taste, sleep, and the circuits that generate respiratory rhythms. Additionally, it participates in the analysis of sensory data and is the site where auditory information enters the brain.

Within the pons there are four types of cranial nerves: These are nerves that help control the muscles of the head and receive sensory information from the head:

abducens nerve: These nerves coordinate eye movements.Facial nerve: These are responsible for coordinating movement and sensations in the face.Vestibulocochlear nerve: These process sounds reach the brain and help maintain balance.trigeminal nerve: They help coordinate the action of chewing and transmit sensory information from the face and head.

The pons also contains groups of cells that are responsible for transferring signals from the brain to the cerebellum.

3. Medulla oblongata or medulla oblongata

It is located caudal to the pons and cerebellum. Derived from the caudal portion. The medulla controls many functions outside of conscious control, such as breathing, blood flow, blood pressure, and heart rate. This makes the marrow a vital structure for survival. This structure is also involved in many involuntary reflexes such as coughing, sneezing, and swallowing.

The spinal cord contains four types of cranial nerves inside:

Glossopharyngeal nerve: These nerves coordinate some taste sensations, as well as mouth movements.Vagus nerve: These also control mouth movements, as well as our voice and gag reflexes.accessory nerve: These coordinate the movements of the head and neck.hypoglossal nerve: These nerves control the movements of the tongue and the muscles involved in speech.

The medulla transmits signals between the spinal cord and higher levels of the brain, as well as housing nuclei that are centers for automatic and involuntary behaviors.

Functions of the hindbrain

The hindbrain has various functions. Let’s see:

It’s a fundamental passage point for information, from the forebrain to the spinal cord and vice versa. For example, white matter systems. Their neurons collaborate in the sensory information processing.There is a contribution from hindbrain neurons to control of voluntary movement. In addition, they help regulate the autonomic system. The cerebellum, also called the small brain, regulates movement, as if it were a control center. It also receives massive axon inputs, coming from the spinal cord and pons. On the other hand, the cerebellum is responsible for comparing the information that arrives and calculates the sequences of muscle contractions, essential for carrying out movement. The medulla oblongata is responsible for carry somatic information from the spinal cord to the thalamus. In addition, to control the movements of the tongue. And, it is associated with sensory functions of touch and taste. The axons of the auditory nerves They are responsible for carrying information from the ears to the cochlear nuclei of the medulla. The nuclei are responsible for projecting axons to different structures. Among them, the tectum of the midbrain.

Now, the inputs coming from the spinal cord bring information about the spatial position of the body. In addition, the bridge inputs are responsible for carrying information from the cerebral cortex. And, they are responsible for specifying the purpose of the movement.

Possible conditions associated with the hindbrain

If brain development is not adequate, the hindbrain could be affected, as well as its functions, which are vital for our survival. Let’s look at his other conditions:

Injuries to the hindbrain can cause movement problems, such as uncoordinated and inaccurate movements, such as those typical of ataxia. Its damage could lead to deafness, for example, if there is an injury to the cochlear nuclei. Problems related to touch and taste.Dandy Walker syndrome, and Arnold Chiari, syndromes that derive from the abnormal development of the hindbrain. Its damage can cause vomiting, weakness, breathing and circulation problems.Rhombencephalitis, that is, inflammation of the hindbrain caused by different factors .

So, The hindbrain is a fundamental part of our body. Through its motor, sensory and visceral functions it helps regulate it. The consequences of it failing or not being present can seriously affect our survival.

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