Reflexes And Reflex Arcs

Reflexes and reflex arcs: how our nervous system works

Reflexes are automatic reactions to a stimulus that occur without the participation of higher centers of the nervous system. Each reflex depends on the anatomical relationships between neurons that form a reflex arc. The simplest reflex arc includes sensory, intercalary and motor neurons.

Reflexes are the functional units of the nervous system and play an important role in regulating many vital functions such as heart rate, blood pressure, breathing, salivation, digestive tract movements and many others. Much of our activity is also the result of reflexes.

Reflexes can be congenital or acquired. Congenital reflexes are called unconditioned, and acquired ones are called conditioned. Reflexes are also classified according to the number of nerve pathways involved.

An example of a simple reflex is the knee reflex. If you hit the tendon near the kneecap, the tendon receptors will be irritated. The reflex arc will travel to the spinal cord and back, causing the muscle attached to the tendon to contract, causing the leg to suddenly straighten.

There are also more complex reflexes, such as the limb withdrawal reflex when the skin of an arm or leg is severely irritated, which causes the flexor muscles to be stimulated and the injured limb to be withdrawn before further damage occurs.

One of the features of all reflexes is accurate and trouble-free repeatability. This can be demonstrated by the example of a frog, which, possessing only a spinal cord, will invariably raise one of its legs in response to stimulation, even if this occurs repeatedly.

Although most reflexes are useful from the point of view of the animal's survival, they do not require the participation of higher brain centers and are purely reflexive. However, if the reflex is too strong or inadequate, this may indicate the presence of pathology in the nervous system.

Overall, reflexes and reflex arcs are an important part of our nervous system that allows us to respond quickly and effectively to various stimuli in the environment.