Where is the medulla oblongata located in humans? Functions of the human medulla oblongata: what are they? Human medulla oblongata and its most important functions

The brain is the most important organ that regulates absolutely all aspects of human life. It is rather complex anatomical structure. One of its significant departments is the medulla oblongata, the structure and functions of which will be discussed in detail in our article.

In contact with

Classmates

They are divided into several groups:

1. Protective - hiccups, sneezing, coughing, vomiting, etc.
2. Cardiac and vascular reflexes.
3. Regulating the vestibular apparatus.
4. Digestive.
5. Reflexes of ventilation of the lungs.
6. Adjusting reflexes responsible for maintaining posture and muscle tone.

Anatomy

This part of the central nervous system directly involved in information processing, which comes to it from all receptors human body.

The nuclei of five pairs are located in this part of the nervous system. cranial nerves. They are grouped in the caudal region below the floor of the 4th ventricle:

Conducting paths

Pass through the medulla oblongata several conductive sensory pathways from the spinal region to the overlying parts of the central nervous system:

1. Thin.
2. wedge-shaped.
3. Spinothalamic.
4. Spinocerebellar.

The localization of these pathways in the medulla oblongata and spinal cord is identical.

AT lateral department white matter are located efferent pathways:

1. Rubrospinal.
2. Olivospinal.
3. Tectospinal.
4. Reticulospinal.
5. Vestibulospinal.

In the ventral part are the fibers of the corticospinal motor pathway. Its fibers in the medulla oblongata are formed into special formations, which are called pyramids. At the level of the pyramids, 80% of the fibers of the descending pathways form a cross between them. The remaining 20% ​​of the fibers form a cross and go to the opposite side below - at the level spinal cord.

Main functions

There are a large number of tasks that the medulla oblongata is designed to solve. Functions of this part of the nervous system are divided into the following groups:

1. Touch.
2. Reflex.
3. Integrative.
4. Conductor.

Below they will be considered in more detail.

Touch

This kind of function is in the acceptance by neurons of signals from sensory receptors in response to environmental influences or changes in the internal environment of the body. These receptors are formed from sensory epithelial cells or from the nerve endings of sensory neurons. The bodies of sensory neurons are located in the peripheral nodes or in the brainstem itself.

In the neurons of the brain stem, the analysis of signals sent by the respiratory system takes place. This may be a change in the gas composition of the blood or stretching of the pulmonary alveoli. According to these indicators, not only hemodynamics is analyzed, but also the state of metabolic processes. In addition, the activity of the respiratory system is analyzed in the nuclei. Based on the results of such an assessment, there is a reflex regulation of the functions of respiration, blood circulation, and the digestive system.

In addition to internal signals, the centers of the medulla oblongata regulate and process signals about changes in external environment - from temperature receptors, taste, auditory, tactile or pain.

From the centers, the signals are sent along the conductive fibers to the brain regions located above. There, a more subtle analysis and identification of these signals is carried out. As a result of processing these data, certain emotional-volitional and behavioral reactions are formed in the cerebral cortex. Some of them are carried out in the same way with the help of the structures of the medulla oblongata. In particular, a decrease in the content of oxygen in the blood and the accumulation of carbon dioxide can lead to the development in humans discomfort and negative emotional state. As behavioral therapy, a person begins to seek access to fresh air.

Conductor

Conduction functions consist in the fact that nerve impulses are conducted from sensory components through this area to other parts of the nervous system.

Nerve impulses of an afferent nature come to the centers from sensory receptors located:

All these impulses are carried along the fibers of the cranial nerves to the corresponding nuclei, where they are analyzed and, in response to stimuli, an appropriate reflex reaction is formed. From the centers of this department, efferent nerve impulses can be sent to other parts of the trunk or cortex in order to carry out more complex behavioral reactions in response to stimuli.

Integrative

This type of function may appear in the formation of complex reactions, which cannot be limited to the simplest reflex actions. Neurons carry information about some regulatory processes, the implementation of which requires joint participation with other parts of the nervous system, including the cerebral cortex. The algorithm of such complex actions is programmed in the neurons of this part of the brain.

An example of such an effect can be a compensatory change in position eyeballs during a change in the position of the head - nodding, swinging, etc. In this case, there is a well-coordinated interaction of the nuclei oculomotor nerves and vestibular apparatus with the participation of the components of the medial longitudinal bundle.

Some of the neurons of the mesh structure have autonomy and automatism of functions. Its task is to coordinate the nerve centers in various departments central nervous system and their toning.

reflex

The most important reflex functions are - is the regulation of tone skeletal muscles and maintaining posture in space. In addition, the reflex functions include the protective actions of the body, as well as the organization and maintenance of balance. respiratory system and blood circulation.

The medulla oblongata is located in the posterior part of the brain, is a continuation of the spinal cord. This part of the brain regulates vital functions, namely blood circulation and respiration. Damage to this part of the brain leads to death.

Structure

The medulla oblongata consists of and substance, like the entire brain as a whole. The structure of the medulla oblongata can be divided into internal and external. Bottom line (dorsal) is considered the place of exit of the roots of the first cervical spinal nerve, and the upper- bridge of the brain.

External structure

Outwardly, an important part of the brain looks like an onion. It measures 2-3cm. Because this part is a continuation of the spinal cord, then this part of the brain includes anatomical features and spinal cord and brain.

Outwardly, one can distinguish the anterior median line, which separates pyramids(continuation of the anterior funiculi of the spinal cord). Pyramids are a feature of the development of the human brain, tk. they appeared in the course of development. In younger primates, pyramids are also observed, but they are less developed. On the sides of the pyramids there is an oval extension "olive", which contains the nuclei of the same name. Each nucleus contains the olivocerebellar tract.

Internal structure

The nuclei of gray matter are responsible for vital functions:

• Olive nucleus - associated with the dentate nucleus of the cerebellum
• Reticular formation - regulates contact with all the senses and the spinal cord
• Nuclei of 9-12 pairs of cranial nerves, accessory nerve, glossopharyngeal nerve, nervus vagus
• Centers of blood circulation and respiration, which are associated with the nuclei vagus nerve

For communication with the spinal cord and neighboring departments, long conducting paths are responsible: pyramidal and paths of the wedge-shaped and thin bundles.

Functions of the centers of the medulla oblongata:

• Blue spot - the axons of this center can release norepinephrine into the intercellular space, which in turn changes the excitability of neurons
• Dorsal nucleus of the trapezius body - works with hearing aids
• Nuclei reticular formation- affects the nuclei of the cerebral cortex and spinal cord through excitation or inhibition. Forms vegetative centers
• The core of the olive is an intermediate center of balance
• Nuclei of 5-12 pairs of cranial nerves - motor, sensory and autonomic functions
• The nuclei of the wedge-shaped and thin bundle - are associative nuclei of proprioceptive and tactile sensitivity

Functions

The medulla oblongata is responsible for the following main functions:

Touch functions

From sensory receptors, afferent signals are sent to the nuclei of neurons in the medulla oblongata. Then the signal analysis is carried out:

• Respiratory systems - blood gases, pH, Current state stretching of lung tissue
• Circulation - heart rate, blood pressure
• signals from the digestive system

The result of the analysis is the subsequent reaction in the form reflex regulation, which is realized by the centers of the medulla oblongata.

For example, the accumulation of CO 2 in the blood and the decrease in O 2 is causal for the following behavioral reactions, negative emotions, suffocation, and so on. that make a person seek clean air.

Conductor function

This function consists in conducting nerve impulses both in the medulla itself and to neurons in other parts of the brain. Afferent nerve impulses come along the same fibers of 8-12 pairs of cranial nerves to the medulla oblongata. Also, pathways from the spinal cord to the cerebellum, thalamus, and brainstem nuclei pass through this section.

Reflex functions

The main reflex functions include the regulation of muscle tone, protective reflexes and the regulation of vital functions.

The pathways originate in the nuclei of the brainstem, except for the corticospinal pathway. The pathways end in y-motor neurons and interneurons of the spinal cord. With the help of such neurons, it is possible to control the state of the muscles of antagonists, antagonists and synergists. Allows you to connect to a simple movement of additional muscles.

• Rectifying reflexes - restores the position of the body and head. Reflexes work with the help of the vestibular apparatus, muscle stretch receptors. Sometimes the work of reflexes is so fast that we eventually become aware of their action. For example, the action of muscles during slipping.
• Postural reflexes - needed to maintain a certain posture of the body in space, including the necessary muscles
• Labyrinth reflexes - provide a constant position of the head. They are divided into tonic and physical. Physical - maintain the posture of the head in case of imbalance. Tonic - maintain the posture of the head for a long time due to the distribution of control in different muscle groups

defensive reflexes:

• Sneeze reflex - due to chemical or mechanical irritation of the receptors of the nasal mucosa, forced exhalation of air occurs through the nose and mouth. This reflex is divided into 2 phases: respiratory and nasal. Nasal phase - occurs when exposed to the olfactory and lattice nerves. Then the afferent and efferent signals are found in the "sneeze centers" along the conducting paths. The respiratory phase - occurs when a signal is received in the nuclei of the sneeze center and a critical mass of signals accumulates in order to send a signal to the respiratory and motor centers. The center of sneezing is located in the medulla oblongata at the ventromedial border of the descending tract and nucleus trigeminal nerve
• Vomiting is the emptying of the stomach (and, in severe cases, the intestines) through the esophagus and mouth.
• Swallowing is a complex act in which the muscles of the pharynx, oral cavity and esophagus take part.
• Blinking - with irritation of the cornea of ​​\u200b\u200bthe eye and its conjunctiva

• The structure and size of this area change with age.
• Responsible for crossing nerve fibers between the right and left hemispheres
• Damage to the medulla oblongata can lead to instant death (in most cases)

Medulla ( medulla oblongata) is a continuation of the spinal cord. Its structural and functional organization is more complex than that of the spinal cord. Unlike the spinal cord, it does not have a metameric, repeatable structure; the gray matter in it is located not in the center, but with nuclei to the periphery.

In the medulla oblongata there are olives associated with the spinal cord, the extrapyramidal system and the cerebellum - this is a thin and wedge-shaped nucleus of proprioceptive sensitivity (the nucleus of Gaulle and Burdach). Here are the intersections of the descending pyramidal paths and the ascending paths formed by the thin and wedge-shaped bundles (Gaulle and Burdakh), the reticular formation.

The medulla oblongata is involved in the implementation of vegetative, somatic, gustatory, auditory, vestibular reflexes, ensures the implementation of complex reflexes that require the sequential inclusion of different muscle groups, which is observed, for example, when swallowing.

In the medulla oblongata are the nuclei of some cranial nerves (VIII, XIX, X, XI, XII).

Touch functions. The medulla oblongata regulates a number of sensory functions: the reception of skin sensitivity of the face - in the sensory nucleus of the trigeminal nerve; primary analysis of taste - in the nucleus of the glossopharyngeal nerve; auditory irritations - in the nucleus of the cochlear nerve; vestibular irritations - in the upper vestibular nucleus. In the posterior superior sections of the medulla oblongata, there are paths of skin, deep, visceral sensitivity, some of which switch here to the second neuron (thin and sphenoid nuclei). At the level of the medulla oblongata, the enumerated sensory functions implement the primary analysis of the strength and quality of the stimulation, then the processed information is transmitted to the subcortical structures to determine the biological significance of this stimulation.

conductor functions. All ascending and descending pathways of the spinal cord pass through the medulla oblongata: spinal-thalamic, corticospinal, rubrospinal. The vestibulospinal, olivospinal and reticulospinal tracts originate in it, providing tone and coordination of muscle reactions, the paths from the cortex end. big brain- corticoreticular pathways.

Brain structures such as the bridge, midbrain, cerebellum, thalamus, hypothalamus and cerebral cortex, have bilateral connections with the medulla oblongata. The presence of these connections indicates the participation of the medulla oblongata in the regulation of skeletal muscle tone, autonomic and higher integrative functions, and the analysis of sensory stimuli.

reflex functions. In the medulla oblongata are vital centers - respiratory and vasomotor. It organizes and implements a number of protective reflexes: vomiting, sneezing, coughing, lacrimation, closing of the eyelids, reflexes of eating behavior are organized: sucking, chewing, swallowing.

In addition, the medulla oblongata is involved in the formation of postural reflexes. These reflexes are formed by afferentation from the receptors of the vestibule of the cochlea and the semicircular canals to the superior vestibular nucleus; from here, the processed information for assessing the need for a change in posture is sent to the lateral and medial vestibular nuclei. These nuclei are involved in determining which muscle systems, segments of the spinal cord should take part in a change in posture, therefore, from the neurons of the medial and lateral nuclei, along the vestibulospinal pathway, the signal arrives at the anterior horns of the corresponding segments of the spinal cord, innervating the muscles, whose participation in changing the posture in necessary at the moment.

Changes in posture, position, movement are provided by static and statokinetic reflexes. Static reflexes regulate tone skeletal muscle in order to maintain a certain position of the body. Statokinetic reflexes cause a redistribution of the tone of the muscles of the body to maintain posture and position during accelerated rectilinear or rotational movements.

Most of the autonomic reflexes of the medulla oblongata are realized through the nuclei of the vagus nerve located in it, which receive information about the state of activity of the heart, blood vessels, digestive tract, lungs, etc. In response to this information, motor and secretory reactions of these organs arise. Excitation of the nuclei of the vagus nerve causes an increase in the contraction of the smooth muscles of the stomach, intestines, gallbladder and, at the same time, relaxation of the sphincters of these organs. At the same time, the work of the heart slows down and weakens, the lumen of the bronchi narrows.

The center of salivation is localized in the medulla oblongata, the parasympathetic part of which provides an increase in general secretion, and the sympathetic part - protein secretion of the salivary glands.

The respiratory and vasomotor centers are located in the structure of the reticular formation of the medulla oblongata. The peculiarity of these centers is that their neurons are able to be excited reflexively and under the influence of chemical stimuli.

The respiratory center is localized in the medial part of the reticular formation of each symmetrical half of the medulla oblongata and is divided into two parts, inhalation and exhalation.

In the reticular formation of the medulla oblongata, another vital center is represented - the vasomotor center (regulation of vascular tone). It functions in conjunction with the overlying structures of the brain and, above all, with the hypothalamus. Excitation of the vasomotor center always changes the rhythm of breathing, the tone of the bronchi, the muscles of the intestines, the bladder, etc. This is due to the fact that the reticular formation of the medulla oblongata has synaptic connections with the hypothalamus and other centers.

In the middle sections of the reticular formation there are neurons that form the reticulospinal pathway, which has an inhibitory effect on the motor neurons of the spinal cord. At the bottom of the IV ventricle, the neurons of the "blue spot" are located. Their mediator is norepinephrine. These neurons cause activation of the reticulospinal pathway during REM sleep, which leads to inhibition of spinal reflexes and a decrease in muscle tone.

Damage to the medulla oblongata most often leads to lethal outcome. Partial damage to the left or right half of the medulla oblongata above the intersection of the ascending pathways of proprioceptive sensitivity causes disturbances in the sensitivity and work of the muscles of the face and head on the side of the damage. At the same time, on the opposite side relative to the side of the injury, there are violations of skin sensitivity and motor paralysis of the trunk and limbs. This is due to the fact that the ascending and descending pathways from the spinal cord and into the spinal cord intersect, and the nuclei of the cranial nerves innervate their half of the head, i.e. cranial nerves do not cross.

The reticular formation of the bridge is a continuation of the reticular formation of the medulla oblongata and the beginning of the same midbrain system. The axons of the neurons of the reticular formation of the bridge go to the cerebellum, to the spinal cord (reticulospinal pathway). The latter activate the neurons of the spinal cord. The pontine reticular formation affects the cerebral cortex, causing it to activate or sleepy state. There are two groups of nuclei that belong to a common respiratory center. One center activates the inhalation center of the medulla oblongata, the other activates the exhalation center. The neurons of the respiratory center, located in the pons, adapt the work of the respiratory cells of the medulla oblongata in accordance with the changing state of the body.

The human brain is one of the most important organs, which controls and regulates all vital processes of the body. This body stands out the most complex structure, as it consists of many sections (departments), each of which is responsible for a number of functions that it performs.

In this article, we will consider one of these departments - oblong, and also highlight its main functions.

The medulla oblongata acts as a continuation of the spinal cord, which subsequently passes into the brain. Consequently, this section includes some features of both the spinal cord and the initial section of the brain.

In its shape, this section somewhat resembles a truncated cone. The base of this brain cone is located at the top. Next to this department is the Varoliev bridge (above), and below it smoothly flows through the foramen magnum into the spinal cord. The size of the department itself does not exceed 25 ml, and a characteristic heterogeneity is observed in the structure.

Directly in the bulb is gray matter, which is surrounded by nuclei. At the top, superficial grooves are noted, which divide the surface. Before joining with the intermediate part of the brain, thickenings diverge to the right and left sides. These thickenings connect the oblong section with the cerebellum.

The medulla oblongata contains a number of cranial nerves:

• Glossopharyngeal;
• Additional;
• Wandering;
• Sublingual;
• Part of the vestibulocochlear nerve.

Also external and internal structure The human medulla oblongata includes a number of additional features. Note that the outer part of the department is covered with an epithelial smooth membrane, which consists of special satellite cells. Inner surface characterized by the presence a large number conductor paths.

The medulla oblongata is subdivided into a number of separate surfaces:

• Dorsal;
• Ventral;
• 2 side.

The dorsal surface is located in the occipital region, and then rushes inside the skull. The cords are localized on the sides. There is also a groove on the dorsal surface, which divides the surface into two parts.

The ventral surface of the medulla oblongata is located in front on the outer part, along the entire length. The surface is divided into 2 halves by a vertical fissure in the middle, which is connected with the fissure of the spinal cord. On the sides there are rollers, namely 2 pyramids with bundles of fibers connecting the cerebral cortex with the cranial nuclei of the cranial nerves.

Reflexes and centers

This part of the brain acts as a conductor for a large number of reflexes. These include:

• Protective reflexes (sneezing, hiccups, coughing, vomiting, etc.);
• Vascular and cardiac reflexes;
• Reflexes that regulate the vestibular apparatus;
• Digestive reflexes;
• Reflexes that carry out ventilation of the lungs;
• Muscle tone reflexes responsible for maintaining a posture (adjusting reflexes);

Also in the oblong section are the following regulatory centers:

• Center for the regulation of salivation. Responsible for the possibility of increasing the required volume and regulating the structure of saliva.
• Respiratory control center, in which excitation is carried out under the influence of external stimuli (usually chemical) nerve cells;
• The vasomotor center, which controls the work and condition of the vessels, as well as their indicators of interaction with the hypothalamus.

Therefore, it can be established that the oblong brain department takes a direct part in the processing of incoming information from all receptors of the human body. He also takes part in the activities of the musculoskeletal system, as well as thought processes.

Although the brain is divided into several of its departments, each of which is responsible for a certain number of functions, it is still considered a single organ.

Functions

The medulla oblongata performs a number of vital functions, and even a slight violation of them leads to serious consequences.

To date, there are 3 main groups of functions that the medulla oblongata performs. These include:

1. Touch

This group is responsible for facial sensitivity at the level of receptors, taste and auditory analysis.

The sensory function is carried out as follows: the area of ​​the medulla oblongata is processed and then redirects impulses to the subcortical areas coming from external stimuli (smells, tastes, etc.).

1. reflex

Specialists divide these functions of the human medulla oblongata into 2 types:

• paramount;
• Minor.

Regardless of what type the function being performed belongs to, their occurrence occurs due to the fact that information about the stimulus is transmitted via nerve fibers, which subsequently flow into the medulla oblongata, and which, in turn, is engaged in their processing and analysis.

The activity of autonomous reflexes occurs due to the structure of the nuclei of the vagus nerve. The work of the entire human body is almost completely transformed into a response motor and secretory reaction of a certain organ. For example, when accelerating or decelerating heart rate, there is an increase in the secretion of internal glands (salivation increases).

1. Conductor

The implementation of this function occurs due to the fact that numerous ascending and descending paths are localized in the medulla oblongata. It is with the help of them that this area transmits information to other parts of the brain.

Conclusion

The size and structure of this department changes as a person grows up. Consequently, in a newly born baby, this department is the largest in comparison with others than in an adult. The full formation of the medulla oblongata is noted by the age of 7.

Quite a lot of people know that different sides human body correspond to different hemispheres of the brain and that right side body controls left hemisphere, a left side- right. It is in the medulla oblongata that the nerve fibers cross, moving from the left side to the right and vice versa.

As we have already noted, the centers vital for human life (cardiovascular, respiratory) are located in the medulla oblongata. Consequently, various violations of this department, even the most insignificant, can lead to such consequences as:

• Stop breathing;
• Termination of the work of the cardiovascular system;
• Partial or complete paralysis.

Video

Role brain activity in a person's life is huge. The brain of a higher mammal regulates all important functions and consists of 2 parts - dorsal and head. The brain contains 5 compartments, one of which is the medulla oblongata. It controls the autonomic nervous system.

Structure

The human medulla oblongata (lat. Myelencephalon) is just a part of the brain. This department is located between the dorsal and middle, in the posterior cranial fossa. It is a thickened continuation of the spinal cord. It looks like the head of an onion, which is squeezed in the back and has a slight bulge in front. This department connects the cerebellar part and the bridge with the help of special processes.

Below, this area smoothly flows into the dorsal region. The lower boundary is determined by the place of output of the superior radicular thread of the 1st cervical nerve. From above, it borders on the pons. This part is separated from it by a perpendicular bulbar-bridge groove. The longitudinal size of this area is 2.5-3.2 cm, transverse - 1.5 cm, anteroposterior - 1 cm.

The structure of this department is heterogeneous, it consists of a gray and white substance. Inside is a grayish substance. It is surrounded by tiny nuclei. white matter located outside. It surrounds a grayish substance. The white part consists of short and long fibers.

Long fibers are pathways that pass through the spinal cord. They intersect in the area of ​​the pyramids. In the nuclei of the posterior cords there are bodies of neurons of upwardly reaching fibers. The processes of these neurons go from the medulla oblongata to the thalamus. The fibers form a medial loop that crosses in the medulla oblongata. In this department there are 2 crossroads of long conducting paths.

The short ones are bundles of fibers that connect the nuclei of the gray matter to each other. The nuclei of the medulla oblongata are connected to neighboring parts of the brain.

External structure

The outer anterior part of the medulla oblongata is the ventral surface. It consists of paired cone-shaped lateral lobes that expand upward. They are formed by pyramidal tracts and have a median fissure. Olives are located near the pyramids. They are separated from the pyramids by a sulcus, which is a direct continuation of the anterolateral sulcus of the spinal cord. The transition of the sulcus from the dorsal medulla to the oblong is smoothed out by the outer arcuate fibers.

The back outer part is the dorsal surface. It looks like two cylindrical thickenings, which are separated by a median sulcus. This part consists of fibrous bundles that are connected to the spinal cord.

On the dorsal side there are two bundles: thin and wedge-shaped. They end in tubercles of a thin and wedge-shaped nucleus. On the dorsal surface is the lower part of the rhomboid fossa and the lower cerebellar peduncles. Here is the posterior choroid plexus.

Between the ventral and dorsal surfaces are side surfaces. They have grooves originating in the spinal cord.

Internal structure

The internal structure coordinates such functions: metabolic processes, circulation, breathing, movement, balance. On the transverse section of the medulla oblongata, made at the level of the olives, furrows emerging from the spinal cord are visible. Between them are the pyramidal tracts.

Outside of the pyramids are small tubercles. These are olives. Inside them there are lower olive kernels. They are convoluted plates of a gray substance. The olive nuclei communicate with the nuclei of the cerebellum and are responsible for the balance and activity of the vestibular apparatus. Between them are fibers. Between the pyramid and the olive is the anterior furrow.

In the posterolateral sections, there are ascending pathways that connect the lower part of the brain with upper divisions. In the dorsal part of the medulla oblongata there are nuclei of the vagus, glossopharyngeal, accessory cranial nerve.

The ventral part of the medulla oblongata is a reticular formation. It is formed due to the interweaving of nerve fibers and the nerve cells between them. The motor part of the reticular formation contains centers that control breathing and blood circulation.

Tasks

The main task of the medulla oblongata, based on the features of its structure and functions performed, is to provide various reflexes. These include: protective, digestive, cardiovascular, tonic, as well as those responsible for lung ventilation and muscle tone.

How protective reflexes work:

• when poison or low-quality food enters the stomach, a gag reflex is triggered;
• when dust enters the nasopharynx, sneezing occurs;
• mucus secreted in the nose protects the body from bacteria and viruses;
• coughing attacks clear the bronchi of mucus;
• tearing and blinking protects the eyes from foreign objects, and the corneas - from drying out.

In this part of the brain there are nerve centers responsible for many reflexes: digestion, respiration, muscle tone, sucking, blinking, cardiovascular, thermoregulation. This department is involved in the processing of information from all receptors in the body. It also controls movement and thought processes.

The breath control center works like this: neurons are excited under the influence of chemical stimuli. The center itself consists of several groups of neurons, which belong to different areas medulla oblongata.

Vascular tone is controlled by the vasomotor center located in the medulla oblongata, which works together with the hypothalamus. Chewing occurs when the receptors of the oral cavity are irritated. Salivation is regulated in the medulla oblongata, which controls the volume and composition of saliva.

Functions

The functions that the medulla oblongata regulates are important for the human body. If this organ is affected by injuries or strokes, a person may stop breathing, heart, which will lead to death.

What are the functions of the medulla oblongata and what is its physiology?

The medulla oblongata performs the following main functions:

• reflex;
• conductive;
• sensory.

8 pairs of cranial nerves emerge from it (from 5 to 12). This department has a direct sensory and motor connection with the periphery. Impulses from receptors go to it along sensory fibers skin head, nose, taste buds, mucous membranes of the eyes, from the hearing organs, receptors of the larynx, trachea and lungs, from the vestibular apparatus, as well as from the perceiving interoreceptors of the digestive and cardiovascular systems.

Functions of the human medulla oblongata:

• regulation of complex unconditioned reflexes responsible for protecting the body (sneezing, coughing, vomiting, lacrimation);
• providing complex unconditioned reflexes associated with digestion (swallowing, sucking, salivation);
• regulation of protective and orienting reflexes of vision, speech, hearing and facial expressions;
• ensuring automatism of breathing and blood circulation;
• maintaining body balance and muscle tone.

Reflex arcs pass through the nuclei of the medulla oblongata, providing coughing, sneezing, and tearing reflexes. In the very nuclei of the medulla oblongata there are centers that are responsible for the act of swallowing, the activity digestive glands, heart, blood vessels, regulation of respiration.

The reflex functions of this organ are determined by the fact that the nuclei of the nerves are laid here and there are clusters of nerve cells. The nuclei are interconnected and form centers of various reflex acts.

The functions of reflexes are divided into 2 types: primary and secondary. The respiratory and vasomotor centers are vitally important primary centers, since a whole series of respiratory and cardiac reflexes closes in them.

This brain region contains important reflex centers. Each center regulates the activities of a particular body. Information from the stimulus is transmitted along the nerve fibers. They flow into the medulla oblongata. This is where signal processing and analysis takes place. From the centers, impulses are transmitted to the organs and cause changes in their activity, for example, increased activity or inhibition.

Through the medulla oblongata, the following reflexes are carried out:

• protective;
• muscle tone;
• digestive;
• cardiovascular;
• respiratory;
• vestibular;
• motor.

The reflex function of muscle tone and posture maintenance is performed not only by this brain region, but also by other nervous structures. This organ provides at the reflex level motor functions and also participates in arbitrary movements. Protective reflexes - sneezing, vomiting, swallowing - are carried out thanks to the centers located here. The main purpose of such centers is to coordinate the activity of neurons.

The conduction function is as follows: in the medulla oblongata there are ascending and descending fibers of the spinal cord: corticospinal, spinal-thalamic, rubrospinal. With the help of these pathways, information is transmitted to the parts of the brain and processed impulses back to the organs.

The olivospinal, vestibulospinal and reticulospinal tracts originate in this part. They provide tone and coordination of muscle reactions. In this organ, corticoreticular pathways from the cortex end, as well as upward fibers of proprioceptive sensitivity from the spinal cord.

Various parts of the brain - the pons, cerebellum, midbrain, hypothalamus, thalamus and cortex - have bilateral connections with the medulla oblongata. Thanks to such connections, this organ is involved in the regulation of skeletal muscle tone and the analysis of sensory stimuli.

The medulla oblongata regulates such sensory functions.