High sensitivity is a term used to refer to highly sensitive areas of the body. Development of the peripheral nervous system will produce a pattern of skin innervated by cutaneous neurons of a certain spinal or cranial nerves. These are called dermatomes and represent specific regions of nerve reception of sensory impulses. The pattern of the dermatome is of major clinical significance when a physicianmycontentbreak desires to anesthetize a particular portion of the body. As certain areas of the body are much more sensitive than others, it is sometimes necessary to block more than one dermatome to produce a desired result. Because adjacent dermatomes overlap in the arms, legs, groin and buttocks areas, at least three spinal nerves must be blocked to achieve a loss of feeling in these regions.