The reflex arc is defined as the path a nerve impulse has to travel from the receptor to the effector. The receptor is responsible for receiving the stimulus and then transmitting it to the sensory neurons. The impulse then travels through the central nervous system, and from there it is fed back to motor neurons and effectors. The effector works on the basis of close agreement with the nervous center. The reflex arc should be associated with conditioned and unconditional reflexes.
Types of reflex arcs
There are two types reflex arcs. The classification is based on the number of neurons involved in transmitting the nerve impulse.
Reflex arc monosynaptic works by using 2 neurons at the level of the spinal cord. Accordingly, it is called simple a reflex arc. Characterized reflex arc it only functions while stretching. It occurs in the intestinal nervous system and belongs to the group unconditional reflexes.
Reflex arc polysynaptic affects some unconditional reflexes i conditional. In this arc, several neurons mediate the transmission of the nerve impulse from the receptor to the effector.
Construction of the reflex arc scheme
Reflex arc it always consists of five elements and they are:
- receptor – its role is to receive stimuli from the environment;
- sensory neuron – transmits an impulse from the nervous center to the effector;
- nerve center – located in the spinal cord;
- motor neuron – is responsible for transmitting the impulse from the nervous center to the effector;
- effector – a muscle or gland that carries out an action given to it by a nerve center.
Unconditional reflexes i conditional they consist of the same elements. So they function in the same way. Reflex arc occurs naturally in humans.
Reflex it ceases when damage occurs on any section of its road.
Types of reflexes
Unconditional reflexes to reflexes congenital. They are characterized by a very quick response to a stimulus. They do not require brain support and stimulus analysis. Unconditional reflexes it is primarily defensive reflexes. The reaction to such stimuli occurs before the information about their occurrence reaches the brain. Unconditional reflexes in utero expire. These include: reflex sucking, crying, grabs.
Among unconditional reflexes stands out:
- bending reflex and mutual inhibition – occurs when the pain stimulus appears. It consists in loosening the extensor in the place where the stimulus is received;
- crossed extension reflex – is related to the flexion and extension reflex. The reflex is that when one side of the body is injured, the other side of the body receives support from the nerve center to prevent the person from falling and the further consequences of the injury.
Replaced unconditional reflexes to polysynaptic reflexes.
Conditional reflexes is acquired in the course of life. They are characterized by the fact that they require repeatability in their training. The response to the stimulus is slower than it was unconditional reflexes.
Conditional reflexes are based on unconditional reflexes. They were researched by Ivan Pavlov at the beginning of the XNUMXth century. His experiment proved that it occurs in dogs conditioned reflex. It was salivation at the very thought of getting food. Giving food to your dog’s mouth causes saliva to flow. This reaction occurs without learning it. On the other hand, you can get a salivation reaction to any signal. Reflex such appears due to the multiple association of the stimulus with the serving of food. Pavlov called it a reinforcement conditional stimulus. Conditioning is most effective when the time is in between conditional stimulus a unconditional it’s not too big.
Currently for conditioning classical ones are considered to be carried out according to a specific scheme, namely stimulus-response. Occasionally there are annotations that it is about emotional or autonomic nervous system reactions. As already mentioned, unconditional reflexes they occur at the level of the spinal cord. This is not the case with conditioned reflexes. These require the involvement of the brain as well as consciously controlled muscles.
Conditional reflexes they are formed by the repetition of a certain situation, and certain phenomena are associated with each other.