Anesthetic drugs serve to block the pain and other somatic sensations by inactivating the central nervous system. For example, procaine is used to block the pain sensation in the skin during the suturing of a gash or during dental work. These drugs target the voltage-gated Na+ channels and do not allow them to open. As a result, action potentials cannot propagate and pain signals do not reach the CNS. Some of these drugs also lower the speed of propagation of action potential.
A person instinctively curls over his abdominal area in times of danger. Why? To prevent a smaller target and also to protect the internal organs and genitalia.
