Anatomy of brain

What parts is our brain made of? The human brain is one of the most complex organs of our body. It consists of various parts or structures that perform different functions. The brain and its parts work in a coordinated and unitary way. To do this, different parts of the brain use the thousands of connections they establish between each other, and with the rest of the body. Here is a description of the structure of the brain, the different parts of the human brain and their functions.

Brain structure

The human brain is part of the Central Nervous System (CNS). In the CNS we distinguish two parts: the brain and the spinal cord.

  • The brainis the central part of the CNS that is enclosed and protected within the skull. The brain would be only part of the entire brain (although it could be said that it is the most representative part).
  • The spinal cordis a long whitish cord located in the vertebral canal and acts as a kind of highway responsible for transmitting all the information provided by the brain to the rest of the body.

Therefore, the brain and brain is not the same. To be able to differentiate well between what is brain and what is brain, we must know the division of embryonic development of the CNS. Broadly speaking, during its development, the brain of humans is divided into three different “brains” according to their level of phylogenetic development: Rhombencephalon (“caudal or posterior brain”), midbrain (“middle brain”) and proscencephalon (“brain previous”).

THE ROMBENCÉFALO, OR REAR BRAIN: It is the oldest and least evolved structure, present in all vertebrate species. The structuring and organization of the posterior brain is the simplest of the three. He is in charge of regulating the basic functions for survival and movement control. Injuries to these structures can lead to death, coma or serious disabilities. It is located just at the top of the spinal cord, and is formed by several structures:

  • Myncephalon: This structure will evolve in the medulla. It helps to control automatic functions such as breathing, blood pressure, heart rate, digestion … etc.
  • Metencephalon: This structure will involve two distinct parts: the brainstem bridge (also known as the Varolio bridge, annular or cerbral protuberance). and the cerebellum. For its part, the brainstem bridge is the portion of the brainstem that is located between the medulla and the midbrain. Its function is to connect the spinal cord and spinal bulb with the superior structures of the hemispheres of the cerebral cortex and / or with the cerebellum. It is involved in the control of automatic functions of the body and has an important role in the levels of excitement (alertness) and awareness, and in the regulation of sleep. Instead, the cerebellumIt is located below the cerebral hemispheres, being the second largest structure in the brain. In the cerebellum all the information that comes from the sensory and motor pathways of the brain is integrated, so its main function is that of movement control. It also helps to control posture and balance, as well as enables people to learn to move, walk, ride a bike… In addition, it is also involved in some cognitive activities related to language, visuospatial abilities, memory, executive functions, attention or even emotions. Damage to this structure can cause problems of movement, coordination and postural control, but also causes dysfunctions in higher cognitive processes with which it is connected.

THE MESENCÉFALO OR MEDIUM BRAIN: It is the structure that joins the posterior brain with the previous one, driving the motor and sensory impulses between them. Its correct functioning is a prerequisite for conscious experience. Lesions in this area of ​​the brain may be responsible, among other things, for some movement disorders such as tremor, stiffness, strange movements …

THE PROSENCEPHAL OR PREVIOUS BRAIN: It is the most developed, evolved brain structure with a higher organization and complexity. It consists of two main parts:

  • Diencephalon:It is hidden by the cerebral hemispheres, so it is located “” inside “” of the brain. It consists of structures as important as the thalamus and the hypothalamus. The Thalamus is like a relay station for the information handled by the brain: it transmits most of the perceived sensory signals (auditory, visual and touch) and allows them to be processed in other parts of the brain. It is also involved in motor control. The hypothalamus , on the other hand, is a gland located in the central area of ​​the base of the brain. It has a very important role in the regulation of emotions and many other bodily functions such as appetite, thirst and sleep.
  • Telencephalon or the “cerebrum”:It is what we know colloquially as “” brain “. It covers the entire cerebral cortex (the rough layer of gray matter, with grooves and folds that covers much of the structures mentioned above), the basal ganglia, the hippocampus … During embryological development, you can differentiate between “” neo-striated ” “,” “paleoestriado” “and” “arquiestriado” “.

Brain anatomy and its functions

In turn, in the brain or “cerebrum” (corresponding to the telencephalon) we can differentiate different areas. The different parts of the brain and their main functions are:

THE BASAL GANGLES: They are subcortical neuronal structures, that is, they are covered by the cerebral cortex (or hemispheres of the brain). Its main function is to start and integrate the movement. They receive information from the cerebral cortex and the brainstem, process it and project it back to the cortex, the spinal cord and the brainstem to allow coordination of the movement. It is formed of several structures:

  • Caudate nucleus: it is a “C” shaped nucleus, which is involved in the control of the voluntary movement, although it is also involved in learning and memory processes.
  • Putamen: is responsible for the preparation and execution of limb movements.
  • Pale balloon: its main function is to regulate automatic and non-conscious movements.
  • Tonsil: plays a key role in emotions, especially in fear. The tonsil helps to store and classify emotionally charged memories.

THE HIPOCAMPO: It is a small subcortical structure shaped like a seahorse that plays an important role in the formation of memory (Kosslyn, 1994), both in the classification of information and in long-term memory.

THE BRAIN CORTEX:The cerebral cortex is a layer formed by gray matter (neuronal nuclei). At a glance you can see many turns, bumps and convolutions, which gives it its characteristic appearance. This strange arrangement allows to increase the area of ​​cerebral cortex available within our skull. The convolutions are delimited by the furrows or cerebral fissures. In addition, those fissures that are especially deep, are called fissures. The cortex is divided into two hemispheres: the right hemisphere and the left hemisphere. They are separated by the interhemispheric (or longitudinal) fissure and joined by a structure called the corpus callosum. which allows the transmission of information between both hemispheres. In general terms, we can say that each hemisphere controls one side of the body, but the controls are reversed: the left hemisphere controls the right side of the body and the right hemisphere controls the left side. This phenomenon has been called lateralization of the brain.

EACH HEMISPHERE, IN turn, is divided into 4 lobes . These lobes are delimited by four cerebral fissures: central or Rolando fissure, lateral or Silvio fissure, parieto-occipital fissure and the cingular fissure. The areas of cerebral cortex that remain between these fissures are what we know as lobes:

  • Frontal lobe:It is the largest cerebral lobe of the cerebral cortex. It is located in the front, just behind the forehead. It extends from the most anterior part to the Rolando fissure. It is the command and control center of the human brain: “the great conductor.” It is closely related to executive functions (Miller, 2000; Miller & Cohen, 2001), so it is involved in planning, reasoning and problem solving, judgment and impulse control, and also in the regulation of emotions, such as empathy and generosity, and behavior.
  • Temporal lobe:It is separated from the frontal and parietal lobes by the fissure of Silvio and the limits of the occipital lobe. It is located on the right and left sides of the brain. It is involved in auditory and language processing. It is also involved in memory functions and emotion management.
  • Parietal lobe:Occupies the area between the rolando fissure and the upper part of the parietooccipital fissure. It is responsible for the integration of sensory information. It contributes to the processing of pain and touch among other important functions.
  • Occipital lobe:It is bounded by the posterior extremities of the parietal and temporal lobes (in the back of the brain). It mainly deals with vision (although it delegates the processing of some threads of the vision to other lobes) (Kosslyn, 1994). Analyze aspects such as shape, color and movement to interpret and draw conclusions from visual images.
  • Some authors speak of a fifth lobe, the limbic lobe: The limbic system is made up of several prosencephalic structures, including the amygdala, the thalamus, the hypothalamus, the hippocampus, the cingulate cortex and the corpus callosum, among others. The limbic system manages the physiological responses to emotional stimuli. It is related to memory, attention, emotions, sexual instincts, personality and behavior.

 

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