In the human body, the brain is probably one of the most mysterious and incomprehensible organs. So, scientists still argue about the mechanism of mental activity. Today we will try to systematize their conclusions. We also consider what the brain consists of, what are its functions and what are the most common diseases of this organ.
General structure
A reliable skull box protects the brain around. In it, the organ occupies more than 90% of the place. At the same time, the brain weight is different for men and women. On average, this is 1375 grams for the stronger sex, 1275 grams for the weak. In newborns, brain weight is 10% of the whole body, and in adults - only 2-2.5%. The structure of the organ includes the cerebral hemispheres, trunk and cerebellum.
What does the brain consist of? Science distinguishes the following departments of this body:
- front;
- rear;
- oblong;
- middle;
- intermediate.
Let's consider these sites in more detail. The oblong originates from the spinal cord. It includes white matter (conduction channels) and gray (nerve nuclei). Behind it is the Varoliev bridge. This is a roller of transverse fibers of nerves and gray matter. The main artery passes here. It begins at a point located above the oblong. Gradually, it passes into the cerebellum, which consists of two hemispheres. It is paired with an elongated bridge, midbrain and cerebellum.
In the middle compartment is a pair of visual and auditory tubercles. Nerve fibers that connect the brain and spinal cord depart from them. Between the large hemispheres, a deep gap is visible, inside of which there is a corpus callosum. It connects these two large departments. Hemispheres are covered with bark. This is where mental activity takes place.
What else does the brain consist of? It has three shells:
- Solid is the periosteum of the inner surface, where most pain receptors are located.
- Spider web - closely adjacent to the cortex, but not lining the gyrus. Between it and the hard shell is a serous fluid. Next comes the spinal cord, and then the cortex itself.
- Soft - consists of a system of blood vessels and connective tissue that feeds the brain and is in contact with the entire surface.
Tasks
The brain processes the information that comes from each of the receptors, regulates movements, and engages in the thought process. Each of the departments has its own work. For example, in the medulla oblongata there are nerve centers that ensure the normal functioning of protective reflex mechanisms, such as coughing, blinking, sneezing and vomiting. Its functions also include breathing, swallowing, secretion of saliva and gastric juice.
Varoliev bridge provides the movement of the eyeballs and the muscles of facial expressions. The cerebellum regulates the coordination and coordination of movements. And in the middle brain, regulatory activity is carried out with respect to visual acuity and vision. Thanks to his work, the pupils, for example, can expand and contract. That is, the tone of the eye muscles depends on it. It also includes the nerve centers responsible for orientation in space.
But what does the intermediate brain consist of? There are several of its compartments:
- Thalamus It is also called a switch, since sensations based on pain, temperature, muscle, auditory and other receptors are processed and formed here. Thanks to this center, the states of wakefulness and sleep are changing.
- Hypothalamus. It controls heart rate, blood pressure and body thermoregulation. It is responsible for the emotional state, since it affects the endocrine system to produce hormones to overcome stress. Regulates the feeling of thirst, hunger and satiety, pleasure and sexuality.
- Pituitary. It produces hormones during puberty, development and activity.
- Epithalamus. It consists of the pineal gland, through which circadian rhythms are regulated, healthy sleep and normal activity during the day, adaptability to various conditions are ensured. He has the ability to feel the fluctuations of light waves even through the box of the skull, secreting for this one or another amount of hormones.
What are the cerebral hemispheres responsible for?
The law stores all information about the world and all-round human interactions. It is responsible for the activity of his right limbs. In the left, the work of the speech organs is controlled. This is where analytical, abstract thinking and various calculations take place. On this side, monitoring of the left limbs is provided.
Separately, it is worth mentioning such formations as the ventricles of the brain. They are voids that are lined with ependyma. They are created from the cavity of the neural tube in the form of bubbles, which are transformed into the ventricles of the brain. Their main function is the production and circulation of cerebrospinal fluid. Departments consist of a pair of lateral, third and fourth. The hemispheres are divided into 4 lobes: frontal, temporal, parietal and occipital.
Frontal lobe
This part is like a navigator on a ship. It is she who is responsible for the stay of the human body in an upright position. Here activity, independence, initiative and curiosity are formed. Critical self-esteem can also be created. In a word, the slightest disturbances that occur in the frontal lobe lead to inappropriate human behavior, senseless actions, depression and various mood swings. Behavior control happens through it. Therefore, the work of the control center, also located here, prevents inadequate and asocial actions. The frontal lobe is important for intellectual development. Thanks to her, certain skills are acquired, skills that can be brought to automatism.
Temporal lobes
Here is a repository of long-term memory. Concrete names, objects, events, and connections accumulate in the left, and visual images in the right. Temporal lobes recognize speech. At the same time, the left part deciphers the meaning of what was said, and the right part forms understanding and, in accordance with this, a mimic pattern, showing the mood and perception of others.
Parietal lobes
They perceive pain, cold or heat. The parietal lobe consists of two parts: right and left. Like other organ compartments, they are functionally different. So, the left synthesizes individual fragments, combines them, so that a person is able to read and write. Here, certain algorithms are acquired to achieve a particular result. The right parietal lobe converts all the information that comes from the back of the head and creates a three-dimensional picture. It provides spatial orientation, determines the distance and the like.
Occipital lobe
She perceives visual information. We see objects around as irritants that reflect light from the retina. Through light signals, information about color and movement of objects is converted. Three-dimensional images appear.
Diseases
The zone is subject to a considerable number of diseases. Among the most dangerous are the following:
- tumors;
- viruses;
- vascular disease;
- neurodegenerative ailments.
Let's consider them in more detail. Brain tumors can be very diverse. Moreover, as in other parts of the body, they are both benign and malignant. These formations appear due to a malfunction in the reproductive function of cells. Control is broken. And they begin to multiply greatly. Symptoms include nausea, pain, cramps, loss of consciousness, hallucinations, and blurred vision.
Viral diseases include the following ailments:
- Encephalitis. In humans, consciousness is confused. He feels sleepy all the time, there is a risk of falling into a coma.
- Viral meningitis. I feel a headache. There is fever, vomiting, and general weakness.
- Encephalomyelitis. The patient is dizzy, motility is disturbed, the temperature rises, vomiting may occur.
When a number of diseases occur, the vessels of the brain narrow. There is a protrusion of their walls, destruction and so on. Because of this, memory may be impaired, dizziness, pain can be felt. The blood circulation of the brain does not function well with high blood pressure, rupture of the aneurysm, heart attack, and so on. And due to neurodegenerative diseases, for example , Fahr, Huntington or Alzheimer's disease, memory is impaired, reason is lost, tremors in the limbs, pain are felt, convulsions and cramps occur.
Conclusion
This is the structure of our mysterious organ. It is known that a person uses only a tiny fraction of the possibilities that can be realized through this body. Perhaps someday humanity will be able to reveal its potential much wider than today. In the meantime, scientists are trying to find out more interesting facts about his activities. Although, by the way, these attempts are still not very successful.