Our body, as well as its individual systems and organs, perform dozens of different functions. It is difficult to talk about all of them briefly, so now we will talk about only one - locomotor. It refers to the musculoskeletal system. Bones, being a kind of "levers", are set in motion by muscles through the central nervous system, thereby causing a variety of movements. This is the locomotor function. And now about everything that concerns her, it is worth telling a little more in detail.
The concept of locomotion
He should be considered first. Locomotion is the movement of a person in space, due to his active actions. By the way, this term also applies to animals.
In medicine, under this concept, a type of motor activity is perceived, which is associated with the movement of a person in space. Its result, respectively, are motor acts.
It should also be noted that locomotion is one of two categories of behavior. The second is manipulation. locomotionreferred to as instinctive movements. What does this fact mean? That locomotor function is a feature related to a rigid musculoskeletal system that allows only minimal movement variability.
But that's not all. It is also worth knowing that locomotor problem solving, which manifests itself, for example, in choosing the right path in a maze, often leads to the formation of complex skills. In other words, it becomes an element of intellectual action.
Movement as a phenomenon
It was briefly described above that this is a locomotor function. The concept of movement should also be studied separately.
This is, firstly, one of the key manifestations of vital activity, which ensures the active interaction of man with the environment. And movement comes in many different forms. It appears as a result of many processes occurring at the tissue, cellular, systemic and organ levels.
The movements that the human locomotor function performs are the result of skeletal muscle contraction. After all, it is due to them that one or another posture is maintained, individual links or the entire body move.
It is worth mentioning the protective and support functions. Absolutely everything in the body is interconnected, so these concepts are directly related to locomotion.
So, for example, the protective function of the skeleton is manifested in the presence of various cavities (thoracic, pelvic, cranial, vertebral). All this is a reliable protection for vital organs,in them.
Description of the support function is elementary. The skeleton is the real support for the internal organs and muscles. They are fixed to the bones, thereby being held in a given position.
Classification of movements
Talking about the locomotor function, this topic also needs to be touched upon with attention. When classifying movements, the following nuances are taken into account:
- The nature of the achieved position of body parts. For example, extension and flexion.
- Mechanical properties. In particular, ballistic and rotational.
- Functional values. Here we mean protective and indicative.
All human movements are controlled by brain activity. It is always aimed at the implementation of a certain task, which, in turn, is modeled in a sequence of muscle contractions. This form of activity is called voluntary or conscious.
There is also the concept of the coordinated activity of several muscle groups. This is already called coordination. It is very important in the manifestation of endurance, speed, strength and agility.
Reflexes
They are directly related to the locomotor function. Reflexes are the same motor reactions. They are caused by irritation of sensitive nerve endings and direct excitation of the central nervous system, which spreads to the muscles (effectors) along the centrifugal fibers.
As you know, there are conditioned and unconditioned reflexes. Otherwise, they are called acquired and congenital motorreactions. What is the difference? Congenital reactions are realized through reflex arcs. And the acquired ones appear on the basis of unconditioned reflexes in the course of individual training. It is for this reason that they are considered more plastic.
In both cases, there is a universal classification, which includes:
- Modality (sensory character) of the stimulus that affects the afferent nerve ending. It can be tactile, sound and light.
- The level of nerve structures involved in the organization of the notorious motor reflex. They are cortical, stem and segmental.
- Characteristic of the medium that stimulates receptors. By the way, they are extero-, intero- and proprioceptive.
- Motor activity. There are both simple reflexes (for example, knee) and complex ones (the same provision of movement in space).
- Biological significance. This refers to sexual, indicative, exploratory, defensive and food reflexes.
Physiological characteristics
Should return directly to the locomotor function. It is provided by the interaction of two systems:
- Central. The cerebral cortex, subcortical formations, motor zones, pyramidal bundle, as well as the brain stem, cerebellum and spinal cord columns are involved.
- Peripheral. Only afferent nerve fibers and proprioceptors are involved. However, they are concentrated everywhere - in the articular surfaces,muscles, tendons and ligaments.
When receptors are irritated, impulses occur. Through the nerve conductors, it is transmitted to the spinal cord, and then to the central nervous system. The locomotor function is controlled by the motor analyzer, and those impulses that come from the neurons are then transmitted to the muscles. This is how this process is carried out, in simple terms.
Disorders
It is impossible not to mention the violation of static-locomotor functions. Disorders occur when any of the following occur:
- Injury to the central nerve formations.
- Transmission from the nerve to the muscle of the impulse through the end plate.
- Violation of the conduction of excitation along the nerve pathways.
Disorders of the locomotor function of muscles are divided into ataxia, hypokinesia, astasia, asthenia and hyperkinesia. Each phenomenon should be told separately.
Hypokinesia
It is characterized either by a weakening of the ability to voluntary movements, or by its complete loss. In other words, hypokinesia is a state of insufficient physical activity.
As a rule, it occurs against the background of mental or neurological disorders. A provoking factor can be stupor (apathetic, depressive or catatonic), depressive syndrome, parkinsonism. A simpler reason is a sedentary lifestyle and a sedentary job.
In hypokinesia, muscle innervation is disturbed. If the function does not fall out completely, the person is overcome by paresis. itthe best layout. Because a complete prolapse is fraught with paralysis. But be that as it may, in both cases motor neurons are affected.
In fact, anything can provoke hypokinesia. Risk factors include mechanical damage, intoxication, inflammation, tumor growth, invasive and infectious irritants, internal hemorrhage, etc.
Hyperkinesia
Continuing the theme of locomotor and static function, this phenomenon also needs to be addressed. Hyperkinesia is a disorder that is accompanied by convulsive, uncontrollable muscle contractions. The reason also lies in the defeat of the central nervous system.
The reasons are divided into two categories:
- Exogenous. These are burns, anaphylaxis, inflammation and infectious diseases (in particular tetanus and rabies).
- Endogenous. This category includes pathologies of hereditary origin, tumors, diabetes, uremia and atherosclerosis.
Often hyperkinesia becomes an "accompany" of alkalosis, hypocalcemia, hypoglycemia and hypomagnesemia. Manifested by convulsions, tremors, chorea, tics.
Ataxia
This disorder of static-locomotor function is quite common. It manifests itself in slightly reduced strength indicators of one or another limb. Due to ataxia, movements become awkward and inaccurate, their sequence and continuity are disturbed. The balance is often disturbed.
There are static and dynamic ataxia. ATthe first case, the balance is disturbed in a standing position. In the second, there is a lack of coordination directly during movement.
If a person does not have any type of ataxia, this means that all departments of his central nervous system carry out friendly, highly automated activities.
Asthenia
This violation does not concern any specific locomotor function (for example, feet or hands). Asthenia is a general weakness of the body, manifested in a weakening of muscle tone and rapid fatigue.
The reason is damage to the cerebellum. It is its dysfunction that leads to the fact that the inhibitory effect on a variety of arbitrary acts is weakened. Movements become angular, abrupt, falls may occur. Almost any physical stress causes instant fatigue and the state of oppression that replaces it.
Provoking factors can be very different. The list includes:
- Diseases of the cardiovascular system.
- Problems with the gastrointestinal tract.
- Pathologies of the genitourinary system.
- Hematological ailments.
- Endocrine diseases.
- Systemic pathologies (from allergies to oncological neoplasms).
- Congenital anomalies.
- Infectious diseases.
- Different types of dementias.
But more often the causes of asthenia are metabolic problems, lack of trace elements, poor nutrition and nervous strain.
Astasia
Complete the topic concerning the supporting protective and locomotor function of the skeleton, followed by a discussion of this disorder. Astasia is a rather atypical pathology. This is called a violation of the ability to stand. The reason is a violation of the coordination of the muscles of the body with rather impressive lesions of the corpus callosum and frontal lobes.
Very often, astasia affects people suffering from conversion (dissociative) disorders. They used to be called hysteria. Also, astasia is often combined with abasia (this is the loss of the ability to walk).
The symptoms are specific. In the most severe cases, people cannot even stand on their own. The best scenario is just gait disturbance, loss of balance and tremors in the limbs.
