Vegetative reflexes: their types and significance for the human body
To present the structure of the nervous system to man,which is not related to medicine or biology, is not easy. But most people probably know that there is a central nervous system to which the brain and the peripheral nervous system belong. It consists of a spinal cord that, with the help of nerves, is connected to all tissues and parts of the body and coordinates their interaction.
Function of vegetative reflexes
Thanks to spinal nerves, the spinal cordtransmits information about the state of the internal and external environment to the brain and in the opposite direction. Between the central and peripheral nervous systems there is a close relationship that ensures the work of the whole organism as a whole.
The term "reflex" comes from the Latin wordreflexus - reflected - the reaction of any organism to a specific effect, with the involvement of the nervous system. Such somatic and vegetative reflexes are characteristic of multicellular organisms that have a nervous system.
Reflex arc
Special receptors - proprioceptors - are inmuscles, tendons, ligaments, periosteum. They continuously send information to the brain about the reduction, tension and movement of various parts of the musculoskeletal system. The central nervous system, continuously processing information, sends signals to the muscles, causing them to contract or relax, maintaining the right posture. Such a two-way flow of impulses is called a reflex arc. Reflexes of the autonomic nervous system occur automatically, that is, they are not controlled by consciousness.
In the peripheral nervous system recognize reflex arcs:
• vegetative reflexes - neural chains of internal organs: liver, kidneys, heart, stomach, intestines;
• somatic reflexes - neural chains covering skeletal muscles.
The most common reflex arc of somaticThe vegetative reflex is formed with the help of two neurons - motor and sensory. This includes, for example, knee-jerk reflex. Often more than 3 neurons participate in the reflex arc - motor, sensory, and intercalary. It occurs if you prick a finger with a needle. This is an example of a spinal reflex, its arc passes through the spinal cord, without affecting the head. This arc of the vegetative reflex allows a person to respond automatically to external stimuli, for example, to withdraw his hand from the source of pain, to change the size of the pupil, as a reaction to the brightness of light. It also helps to regulate the processes that take place inside the body.
Involuntary movements
It is a question of normal spinal cordAutonomic reflexes without participation of the cortex of the cerebral hemispheres. An example is the hand touching a hot object and its sharp jerking. In this case, the impulses go along the sensory nerves to the spinal cord, and from there to the motoneurons immediately back to the muscles. An example of this is unconditioned reflexes: coughing, sneezing, blinking, flinching. The involuntary character is usually the movements associated with the manifestation of the senses: with severe anger, involuntary clenching of the teeth or clenching of the fists; a sincere laugh or smile.
How are reflexes subdivided?
There are the following classifications of reflexes:
- by the method of their origin;
- type of receptor;
- biological function;
- complexity of constructing a reflex arc.
There are a lot of them, they are classified as follows.
1. By origin distinguish: unconditional and conditional.
2. According to the receptor: exteroceptive, which includes all sensory organs; interoceptive, when receptors of internal organs are used; Proprioceptive with the use of receptors of muscles, joints and tendons.
3. On efferent links:
- somatic - the reaction of the muscles of the skeleton;
- vegetative reflexes - reactions of internal organs: secretory, digestive, cardiovascular.
4. In terms of their functions, the reflexes are:
- protective;
- sexual,
- indicative.
For the realization of autonomic reflexes,continuity of all links of the arc. Damage to each of them leads to the loss of the reflex. With the transformation of the surrounding world during life in the cortex of the human hemispheres, conditioned reflex connections are formed, the system of which is the basis of most habits and skills acquired during life.
Nervous system in children
If compared with other systems of the body,the nervous system of the child at the time of birth is the most imperfect, and the behavior of the baby is based on congenital reflexes. During the first months of life, most of the vegetative reflexes help the baby react to stimuli from the environment and adapt to new conditions of existence. During this period, the sucking and swallowing reflexes are the most important, since they satisfy the most important need of the newborn in nutrition. They occur already at the 18th week of intrauterine fetal development.
Reflexes of newborns
If the baby is given a pacifier or a cam, it will besuck, even if ungainly. If you touch the corner of the baby's lips, he will turn his head in this direction, and open his mouth in search of his mother's breast. This is a reflexive reflex. It does not need to be called specially: every time it is manifested, when the baby is hungry, and my mother is going to feed him. If the newborn is put on the tummy, it will necessarily turn the head to the side. This is a protective reflex. Parents are well aware of how the baby grasps and holds the object placed in his hand. This reflexive grasp of the object is the manifestation of a grasping reflex. A real, conscious capture of objects will appear in him a little later - in 3-4 months.
There is an interesting reflex, called the palm-oral, or the reflex of Babkin. It consists in the fact that if you press your finger with your finger the palm of the baby in the area of the thumb, it opens the mouth.
Automatic crawling and walking of babies is a type of reflexes
The child of the first three months is able tounconsciously creep. If you put it on your tummy and touch the soles of your palm, he will try to creep forward. This is a reflex of automatic creeping. It persists for up to 2-3 months, and the ability to crawl consciously from the baby will appear later. If the baby takes the armpits from behind, supporting his head with index fingers, and touching his feet against the surface of the table, he straightens the legs and stands with his feet on the table. If you tilt slightly forward, he will try to walk, while the hands remain motionless. It is a reflex of support and automatic walking, which disappears at the age of three months.
Acquaintance with some vegetative reflexes,which the baby owns from birth, will help parents notice abnormalities in neuropsychological development and consult a doctor. Especially it concerns premature babies, their unconditioned reflexes can be weakened. If parents want to check some of their child's reflexes, remember that this can be done when he is awake and in a good mood, some time after the feeding. It should also be remembered that the nervous system of the baby is characterized by increased fatigue, so it will not be many times in a row at the request of the parents to open the mouth, crawl or walk.
Reflexology
Many methods of alternative medicine nowThey are used by doctors as a useful supplement to official treatment. One such method is reflexotherapy. This ancient method of foot massage consists in the fact that on them, as well as on the hands, there are reflex points associated with the systems of internal organs. According to reflexologists, the directed pressure on these points can relieve tension, improve blood flow and unblock energy along some or other piercing nerve rays associated, for example, with back pain.
