Reflexes: how the body reacts automatically

In short: Reflexes are involuntary, very fast reactions of the body to certain stimuli that occur without conscious control. They mainly serve to protect the body from harm.

In more detail: The so-called reflex arc often runs directly through the spinal cord without involving the brain, making the reaction especially fast.

In detail

• Reflex arc: A stimulus is picked up by a sense organ, carried along a nerve pathway to the spinal cord, and converted there directly into a motor response.
• Protective reflexes: Pulling a hand back from a hot stove is a classic example of a fast protective reflex.
• Monosynaptic reflexes: Reflexes like the knee-jerk reflex involve the same muscle that triggers the stimulus and carries out the response.
• Polysynaptic reflexes: With these, stimulus reception and reaction occur in different muscles or body regions.
• Innate reflexes in infants: Newborns show special reflexes like the grasp reflex, which normally recede as development progresses.
• Diagnostic significance: Doctors check reflexes to get clues about damage to the nervous system or spinal cord.
• Conditioned reflexes: Unlike innate reflexes, certain reactions can be learned through repeated training, as in Pavlov’s famous experiment (nervensystem-aufbau-und-funktion, knochen-muskeln-und-gelenke).