Search results
Results From The WOW.Com Content Network
In neuroanatomy, the primary somatosensory cortex is located in the postcentral gyrus of the brain's parietal lobe, 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 [citation needed].
The term primary comes from the fact that these cortical areas are the first level in a hierarchy of sensory information processing in the brain. This should not be confused with the function of the primary motor cortex, which is the last site in the cortex for processing motor commands. [1]
Primary somatosensory cortex (S1) Secondary somatosensory cortex (S2) Posterior parietal cortex; Gyri. Postcentral gyrus (Primary somesthetic area) Other Precuneus; Brodmann areas 1, 2, 3 (Primary somesthetic area); 5, 7, 23, 26, 29, 31, 39, 40; Occipital lobe. Cortex Primary visual cortex (V1) V2; V3; V4; Gyri. Lateral occipital gyrus; Other ...
The postcentral gyrus is in the parietal lobe and its cortex is the primary somatosensory cortex (Brodmann areas 3, 2 and 1) collectively referred to as S1. BA3 receives the densest projections from the thalamus. BA3a is involved with the sense of relative position of neighboring body parts and amount of effort being used during movement.
The sensory cortex can refer sometimes to the primary somatosensory cortex, or it can be used as a term for the primary and secondary cortices of the different senses (two cortices each, on left and right hemisphere): the visual cortex on the occipital lobes, the auditory cortex on the temporal lobes, the primary olfactory cortex on the uncus of the piriform region of the temporal lobes, the ...
This cortex is typically represented as a sensory homunculus which orients the specific body parts and their respective locations upon the homunculus. Areas such as the appendages, digits, penis, [2] and face can draw their sensory locations upon the somatosensory cortex. The areas which are finely controlled (e.g., the digits) have larger ...
However, connections to the somatosensory cortex suggest that the pyramidal tracts are also responsible for modulating sensory information from the body. [ 1 ] Because most (75-80%) of the connections cross the midline at the level of the medulla and others at the level of the spinal cord, each side of the brain is responsible for controlling ...