The Human Brain. Although men are not the only creatures God has possessed a brain. But the human brain by its shape, composition, size, functioning, and many other specificities is a subject of wonder for the man himself. Do you know that you have a prodigious brain? In this article, we will inform you more about some interesting facts about the human brain.
The brain is an organ located in the skull and composed of neurons, but also other types of cells. It is part of the central nervous system and is in direct contact with the spinal cord.
The brain is the conductor of voluntary movements; it is the center of the treatment of the senses, as is the seat of thought and memory. The brain is a vital organ, indispensable for living. The brain is a great organ and indispensable for the proper functioning of the body. It monopolizes about 20% of the blood so much its nutrient need is great.
The Brain Is the Center of Control
The brain is the center of control of the human body, it manages everything we do. Whether one is thinking, dreaming, playing sports, or even sleeping, the brain takes part in one way or another. This is an example of engineering organized in different parts connected to each other in a very specific way. Each part of the brain has particular tasks to perform, making it an ultimate processor. The brain provides, with the spinal cord, many functions in the body. It performs unconscious functions, such as the control of heart rhythm but also the secretion of hormones, the coordination of voluntary movements, and all intellectual functions and consciousness. Working in tandem with the rest of the nervous system, the brain receives and sends messages, allowing uninterrupted communication between the outside world and the self.
Spinal Cord and the Nervous System
We cannot talk about the human brain without mentioning the spinal cord and the nervous system. Briefly, how do you define the nervous system and the spinal cord?
The nervous system is an animal biological system responsible for coordinating actions with the external environment and for rapid communication between different parts of the body. It exercises control over the whole body which results in voluntary or involuntary acts and sensations that are conscious or unconscious. The nervous system manages the sensory information, coordinates the muscular movements, and regulates the functioning of the other organs.
The spinal cord is part of the central nervous system and is an extension of the brain. The spinal cord is an extension of the brain of the cranial box, from the medulla oblongata and all along the vertebral column in which it is contained. Its role is to distribute the nerves between the brain and the different parts of the body. It is involved in reflexes, for example when one removes one’s hand from a hot cooking plate, directly without passing the nervous information to the brain.
I – First of the Interesting Facts About the Human Brain is its Organization and Structure
The brain is composed of two symmetrical parts: the right hemisphere and the left hemisphere, which are connected to each other by a channel. Some functions, such as speech, take place in the left hemisphere in a right-handed person; others in the right hemisphere.
It should be known that the right brain controls the left part of the body, while the left brain controls the right part because the motor fibers intersect at the lower part of the brain.
The Brain of an Adult Man Weighs About 1.5 KG
Regarding its structure, remember that the brain of an adult man weighs about 1.5 kg on average (usually 1.3 to 1.4 kg, which represents about 2% of the bodyweight for a person 60 kg). It has a volume of about 1,130 cm3 in women and 1,290 cm3 in men, although there are significant individual variations. Compared to an identical body size and surface area, men have an average brain of 100 grams heavier than women. But these differences are not correlated with IQ or other measures of cognitive performance.
The human brain (the most prominent part of the brain) is located above the cerebellum and brainstem. It comprises two cerebral hemispheres (forming with associated structures the telencephalon) and the diencephalon consisting of the thalamus, hypothalamus, epithalamus, and subthalamus.
The human brain has the same structure as that of vertebrates. Neuroanatomy divides it into six main regions defined on the basis of the development of the nervous system from the neural tube: the telencephalon, the diencephalon, the midbrain, the cerebellum, the bridge, and the medulla oblongata. Each of these regions has a complex internal structure. Certain regions of the brain, such as the cerebral cortex or the cerebellum, are formed by layers forming sinuous folds, the cerebral convolutions, which make it possible to increase the cortical surface while lodging in the cranial box. Other regions of the brain represent groups of many nuclei. While clear distinctions can be made from the neural structure, chemistry, and connectivity, thousands of distinct regions can be identified in the brain.
II – Specificity of the Human Brain
The main difference between the brains of man and animals is the presence, in humans, of a highly developed cortex. Indeed, the human brain is, for example, able to make equations, while animals are judged unable to achieve. Mathematics, among others, is a good way to develop your brain to reason because it uses logic. The human brain is capable of very elaborate abstractions: we can imagine stories, sounds, forms, etc., without the fruit of our imagination necessarily being real.
To use one’s brain is to use one’s imagination as well as one’s body because it is the brain that controls our movements. Learning things that require an active presence, such as learning lessons, playing chess, or juggling helps the brain. This neural gymnastics will get them used to make stronger and more numerous electrical connections. This is how we limit the aging of the brain.
III – Anatomy of the Brain and the Nervous System
What is the composition of the brain and the nervous system? What are the main functions of the component parts of the brain? The following lines will tell us more.
1 – Brain Mapping
What did you know about the encephalon? Cerebral cortex and its lobes? From the forebrain? Midbrain? Rhombencephalon? From the cerebellum? Read the rest of this article to learn more.
*** The Encephalon
The brain represents the major part of the human brain and is associated with higher functions such as the control of voluntary behaviors. Thinking, perceiving, planning, and understanding a language, all these functions are under the control of the cerebral hemispheres. The telencephalon is divided into two hemispheres: the right hemisphere and the left hemisphere. The latter communicate with each other by a bundle of nerve fibers called the corpus callosum.
*** The Cerebral Cortex
“In humans, the brain is made up almost exclusively of the [cerebral] cortex. […] Our cortex allows us to think, remember, imagine, it is essentially our cortex that makes us human beings. (Edoardo Boncinelli, Director of Research in Molecular Biology).
On the surface of the brain is a layer of brain tissue called the cerebral cortex. This structure is more commonly called gray matter because of its gray color. The bumpy appearance of the human brain is also due to the characteristics of the cerebral cortex. Indeed, more than two-thirds of the cortex is folded in convolutions, which allows increasing the surface and the number of nerve cells.
The function of the cerebral cortex can be analyzed by dividing the cortex more or less arbitrarily into zones, much like the geographical arrangement in countries and continents. It should also be noted that the cerebral cortex is divided into functional areas, called areas (the three main types of areas being sensory areas, motor areas, and areas of association), each of which assures a precise cognitive function.
There would be an obvious difficulty to house all this surface in the cranial box. In fact, the cortex is creased by furrows (sulcus in scientific Latin) or fissures, of variable depth, delimiting ridges called gyrus or cerebral convolutions. The deepest fissures divide the cortex into lobes. Depending on their situation, we speak of the frontal, parietal, occipital, and temporal lobes.
– The Frontal Lobe
The frontal lobe is involved in the initiation and coordination of movements, in higher cognitive tasks such as problem-solving, thinking, planning, many other aspects of personality, and the formation of emotions. In short, the main functions are the elaboration of thought – the seat of emotions – the place of production of language – and the control of complex movements.
– The Parietal Lobe
The parietal lobe intervenes in sensory processes, attention, and language. A lesion on the right side of the parietal lobe can lead to disturbances of spatial orientation, even in familiar places. If the left side is harmed, the ability to understand spoken or written language can be impaired. In other words, the parietal lobe is the place of the sensitivity and all that concerns the pain, the detection of the temperature, the cutaneous sensitivity…
– The Occipital Lobe
The occipital lobe takes part in visual information including the recognition of shapes and colors. Let’s say, the main functions of the occipital lobe are the detection of visual images and the interpretation of these same faces.
– The Temporal Lobe
As for the temporal lobe, its main functions are the recognition of sounds and phenomena of interpretation – and the place of storage of information, i.e. of memory.
Indeed, the temporal lobe plays a role in the encoding of auditory information and in the integration of information from other sensory modalities. Neurobiologists also believe that the temporal lobe intervenes in short-term memory through the hippocampus and in the memory of emotional responses via the amygdala.
Important Notes on the Cerebral Cortex:
Most neurons in the outer layer of the brain, the cerebral cortex, are not directly related to the muscles or sensory organs. This is the case, for example, billions of neurons of the frontal lobe. Observations of the brain by MRI show that the frontal lobe is activated when one thinks of a word or that one makes operate his memory. If you are what you are, it is especially in the anterior part of your brain that you owe it.
” The prefrontal cortex […] plays an important role in the elaboration of thought, intelligence, motivation, and personality.” It relates the elements of the lived experience necessary to the production of abstract ideas, judgment, perseverance, planning, caring for others and conscience … This is what is developed in this region that distinguishes human beings from other animals “(Human Anatomy and Physiology, from Elaine Marieb).
*** The Forebrain
All these structures form the forebrain. This structure also includes brain nuclei deeply buried under the cortex: the basal ganglia; the thalamus and the hypothalamus.
The basal ganglia help coordinate movement and reward behaviors.
The thalamus plays a coordinating role in sensory information going to the cortex. In other words, it plays an intermediary role of the decoder of the sensory messages between the spinal cord and the midbrain, on the one hand, the hemispheric brain, on the other hand.
The hypothalamus, meanwhile, is the center of control of appetite, defense, and reproduction behaviors, the sleep watch cycle.
*** The Midbrain
The midbrain consists of two pairs of small bulges called colliculi. These groups of neurons play a prominent role in the visual and auditory reflexes and in the transfer of this information to the thalamus. The midbrain also includes scattered islets of neurons in the central nervous system that play an important role in reward mechanisms and mood.
*** The Rhombencephalon
The rhombencephalon includes the pons and the medulla oblongata. This structure allows the control of the respiratory rate, cardiac activity, and the level of glucose in the blood.
*** The Cerebellum
Another part of the rhombencephalon, called the cerebellum, also contains two hemispheres. This structure is involved in the control of movements and in cognitive processes that require coordination. He plays an important role in Pavlovian learning.
In other words, the cerebellum is essential in the control of balance and posture, it also allows the realization of precise movements.
2 – The Spinal Cord
The spinal cord is an extension of the brain in the spine. She receives sensory information from all parts of the body below the head. It uses this information to generate reflexes, for example, in response to pain, and it also transmits sensory information to the brain especially in the cerebral cortex. In addition, the spinal cord generates nerve impulses in the nerves that control the muscles and viscera through reflex activities or voluntary commands from the brain.
3 – The Different Types of Nervous System
The forebrain, midbrain, and spinal cord form the Central Nervous System (CNS). The brain is protected by the cranial box while the spinal cord which is about 43 cm long is protected by the spine.
The central nervous system consists of nerves and small concentrations of gray matter called ganglia. Thus, the nervous system represents a biological system formed by a network of gray matter zones interconnected by bundles of white matter.
The Peripheral Nervous system is the part of the nervous system consisting of ganglia and nerves outside the brain and spinal cord. Its main function is to circulate information between organs and the central nervous system.
The brain sends messages to the peripheral nerves via the spinal cord through the body to control the muscles and internal organs.
The Somatic Nervous System is composed of neurons connecting the CNS with parts of the body that interact with the outside world. The somatic nerves in the cervical region are associated with the neck and arms whereas those in the thoracic region are associated with the thorax and those located in the lumbar and sacral regions interact with the legs.
The Autonomic Nervous System is made up of neurons connecting the CNS with the internal organs. It is divided into two parts. The sympathetic nervous system, which harnesses the energy and resources of the body during stress or excitement, while the parasympatic nervous system conserves energy and resources during a relaxed state or during sleep.
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