neuroanatomy Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defi ...

, the postcentral gyrus is a prominent

gyrus In neuroanatomy, a gyrus (: gyri) is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci (depressions or furrows; : sulcus). Gyri and sulci create the folded appearance of the brain in humans and other mammals. ...

in the lateral

parietal lobe The parietal lobe is one of the four Lobes of the brain, major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus. The parietal lobe integra ...

of the

human brain The human brain is the central organ (anatomy), organ of the nervous system, and with the spinal cord, comprises the central nervous system. It consists of the cerebrum, the brainstem and the cerebellum. The brain controls most of the activi ...

. It is the location of the

primary somatosensory cortex 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 ...

, the main sensory receptive area for the

sense of touch The somatosensory system, or somatic sensory system is a subset of the sensory nervous system. The main functions of the somatosensory system are the perception of external stimuli, the perception of internal stimuli, and the regulation of bod ...

. Like other sensory areas, there is a map of sensory space in this location, called the ''

sensory homunculus A cortical homunculus () is a distorted representation of the human body, based on a neurological "map" of the areas and portions of the human brain dedicated to processing motor functions, and/or sensory functions, for different parts of the ...

''. The primary somatosensory cortex was initially defined from surface stimulation studies of

Wilder Penfield Wilder Graves Penfield (January 26, 1891April 5, 1976) was an American-Canadian neurosurgeon. He expanded brain surgery's methods and techniques, including mapping the functions of various regions of the brain such as the cortical homunculus. ...

, and parallel surface potential studies of Bard, Woolsey, and Marshall. Although initially defined to be roughly the same as

Brodmann area A Brodmann area is a region of the cerebral cortex, in the human or other primate brain, defined by its cytoarchitecture, or histological structure and organization of cells. The concept was first introduced by the German anatomist Korbinian B ...

s 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.

Structure

The lateral postcentral gyrus is bounded by: *

medial longitudinal fissure The longitudinal fissure (or cerebral fissure, great longitudinal fissure, median longitudinal fissure, interhemispheric fissure) is the deep groove that separates the two cerebral hemispheres of the vertebrate brain. Lying within it is a continu ...

medially (to the middle) *

central sulcus In neuroanatomy, the central sulcus (also central fissure, fissure of Rolando, or Rolandic fissure, after Luigi Rolando) is a sulcus, or groove, in the cerebral cortex in the brains of vertebrates. It is sometimes confused with the longitudinal ...

rostrally (in front) *

postcentral sulcus The postcentral sulcus of the parietal lobe lies parallel to, and behind, the central sulcus in the human brain. (A ''sulcus'' is one of the prominent grooves on the surface of the brain.) The postcentral sulcus divides the postcentral gyrus from ...

caudally Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

(in back) *

lateral sulcus The lateral sulcus (or lateral fissure, also called Sylvian fissure, after Franciscus Sylvius) is the most prominent sulcus (neuroanatomy), sulcus of each cerebral hemisphere in the human brain. The lateral sulcus (neuroanatomy), sulcus is a deep ...

inferiorly Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

(underneath) The postcentral gyrus includes

s 1, 2, and 3. Brodmann area 1 occupies the apex of the postcentral gyrus.

Additional images

File:Postcentral gyrus.gif, Postcentral gyrus (animation) File:Gray726 postcentral gyrus.png, Lateral surface of left cerebral hemisphere, viewed from the side. File:Blausen 0103 Brain Sensory&Motor.png, Primary cortices, including primary somatosensory cortex (labeled in purple) File:Postcentral_-_DK_ATLAS.png, Postcentral gyrus, showed on the right hemisphere. File:Postcentral gyrus coronal sections.gif, Postcentral gyrus highlighted in green on coronal T1 MRI images File:Postcentral gyrus sagittal sections.gif, Postcentral gyrus highlighted in green on sagittal T1 MRI images File:Postcentral gyrus transversal sections.gif, Postcentral gyrus highlighted in green on transversal T1 MRI images

External links

* - area 1 * - area 2 * - area 3 {{Authority control 01 Somatosensory system Gyri Parietal lobe

Structure

See also

Additional images

External links