the primary somatosensory area of the cerebral hemisphere is found at postcentral gyrus.
the primary somatosensory area of the cerebral hemisphere is found at postcentral gyrus.
where is the primary somatosensory area of the cerebral hemisphere found?
postcentral gyrus
primary somatosensory cortex









































the primary somatosensory cortex is located in the postcentral gyrus, and is part of the somatosensory system. it was initially defined from surface stimulation studies of wilder penfield, and parallel surface potential studies of bard, woolsey, and marshall. although initially defined to be roughly the same as brodmann areas 3, 1 and 2, more recent work by kaas has suggested that for homogeny with other sensory fields only area 3 should be referred to as "primary somatosensory cortex", as it receives the bulk of the thalamocortical projections from the sensory input fields.
primary somatosensory cortex
at the primary somatosensory cortex, tactile representation is orderly arranged (in an inverted fashion) from the toe (at the top of the cerebral hemisphere) to mouth (at the bottom). however, some body parts may be controlled by partially overlapping regions of cortex. each cerebral hemisphere of the primary somatosensory cortex only contains a tactile representation of the opposite (contralateral) side of the body. the amount of primary somatosensory cortex devoted to a body part is not proportional to the absolute size of the body surface, but, instead, to the relative density of cutaneous tactile receptors on that body part. the density of cutaneous tactile receptors on a body part is generally indicative of the degree of sensitivity of tactile stimulation experienced at said body part. for this reason, the human lips and hands have a larger representation than other body parts.
primary somatosensory cortex