The brain is one of the most complex organs in our body and the one responsible for making everything else function correctly. Despite this, it is also one of the most unknown by the majority of the population. There are many structures that make it up and the neural pathways that pass through it, and there are also many implications that this has in our daily lives.
The midbrain, for example, is one of these structures that make it up, but if I gave you a brain map, would you know how to locate it? Well, depending on the map that was given to you, this would be impossible because, you can’t see it! Did you know this information? If you want to learn this and other things about the midbrain: what it is, parts and functions, as well as why it is so important and its location. Keep reading! In this Psychology-Online article we explain it to you.
What is the midbrain
The midbrain or, also known as the midbrain, is a brain structure very important since it participates in some of the actions controlled by the central nervous system. Which leads us to ensure that an alteration in it will lead to a considerable deterioration in people’s quality of life.
Location of the midbrain
The midbrain is located in the most rostral part of the brainstem and it is very difficult to see with the naked eye when we look at a complete brain, since it is hidden by the .
Importance of the midbrain
Below, we list the reasons why the midbrain is considered to be of utmost importance in terms of the functions it performs in our body and, therefore, the main characteristics of the midbrain:
- The red nucleus and the nucleus, found in the midbrain, are both important components of the motor system. A bundle of axons that arises in the red nucleus constitutes one of the two main fiber systems that transmit information motorboat from the cerebral cortex and cerebellum to the spinal cord.
- Furthermore, the substantia nigra contains neurons whose axons project to the caudate nucleus and the putamen, components of the basal nuclei. Degeneration of these neurons causes Parkinson’s disease.
- As a curiosity, also in the midbrain includes Lewy bodies, although they have a diffuse distribution throughout the cortex, appear to be found in greater quantities here along with other subcortical structures. Provoking, in case of accumulation of these, dementia due to Lewy bodies, which normally begins after having suffered an acute confusional syndrome or after the appearance of serious perceptual alterations such as visual hallucinations.
Parts of the midbrain
Different distinctions can be made when studying the components of the midbrain or midbrain. First we will do it taking into account its two faces (the ventral and the dorsal) and, then, according to its different components:
- ventral face of the midbrain: we find the cerebral peduncles, formed by a set of axons that conduct motor information, we distinguish them because they look like two slightly inclined columns.
- Most dorsal aspect of the midbrain: We find the ventral tegmental area (with the origin of the mesocorticolimbic pathway, formed by dopaminergic neurons), the substantia nigra (with its origin in the nigrostriatal pathway and also formed by dopaminergic neurons), the colliculi and the quadrigeminal tubercles or the tegmentum.
Although mainly, we could divide the parts of the midbrain or midbrain into:
1. Tectum. Located in the dorsal position of the midbrain and formed by protuberances on the dorsal surface of the brain stem:
- Superior quadrigeminal tubercleswhich are a part of the visual system.
- Inferior quadrigeminal tubercleswhich belong to the auditory system.
2. Tegmentum. It is composed of the portion of the midbrain located under the tectum. Understands:
- The rostral end of the reticular formation. It receives sensory information through several pathways, and projects axons to: the cerebral cortex, the thalamus, and the spinal cord.
- The cores that control eye movements.
- The periaquaductal gray matter. Mesencephalic region that surrounds the cerebral aqueduct and contains neuronal circuits involved in typical behaviors of the species.
- The ventral tegmental area.
- The black substance. Dark-colored region of the tegmentum whose neurons communicate with the caudate nucleus and the putamen in the basal nuclei.
3. red core. Large mesencephalic nucleus that receives afferents from the motor cortex and sends axons to motor neurons in the spinal cord.
Functions of the midbrain
The general function of the brain stem is to collect and send both sensory and motor information from the head and face, unlike the spinal cord, which transmits and receives information from the trunk and extremities. Therefore, we could say that brainstem functions are:
- Collects and sends sensory information from head and face.
- It receives information from the brain and distributes motor and vegetative information from the head and face to the periphery.
- Organize reflex responses of head and face.
- Furthermore, it has a special function, which is to control cortical activation, related to the nuclei of the reticular formation.
Some specific vegetative functions are related to controlling the acceptance or rejection of sweet or bitter foods, and can even be modulated by satiety or by physiological signals of hunger, such as a decrease in glucose metabolism, or having food in the digestive system.
Specific, the functions of the midbrain or midbrain would be the following:
- The reticular formation, as it passes through the midbrain, participates in sleep and arousal (or activation), attention, muscle tone, movement and various vital reflexes.
- Interoceptive representation of emotions and homeostatic regulation.
- The quadrigeminal tubercles are involved, in mammals, in the visual reflexes and reactions to mobile stimuli.
- Control of consecutive sequences of typical movements of the species.
If you liked this article about the Midbrain: what it is, parts and functions, we recommend you read this other post about it so that you can expand your knowledge.
This article is merely informative, at Psychology-Online we do not have the power to make a diagnosis or recommend a treatment. We invite you to go to a psychologist to treat your particular case.
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Bibliography
- Carlson, N. R. (2014). Physiology of behavior. Madrid. Pearson Education, S.A.
- Mira, C., (2014). Segmentation of midbrain magnetic resonance images using an active shape model. doctoral thesis. National Autonomous University of Mexico. Mexico DC
- Portell, I. (2015). Brain stem. Autonomous University of Barcelona.