Primary somatosensory cortex (postcentral gyrus)

The primary somatosensory cortex or postcentral gurus is a prominent gyrus in the lateral parietal lobe of the human brain. It is the location of the primary somatosensory cortex, the main sensory receptive area for the sense of touch. Like other sensory areas, there is a map of sensory space in this location, called the sensory homunculus. It is composed of Brodmann areas 1, 2, 3.

Structure
The lateral postcentral gurus is bounded by: The postcentral gyrus includes Brodmann areas 1, 2, and 3. Brodmann area 1 occupies the apex of the postcentral gyrus.
 * medial longitudinal fissure medially (to the middle)
 * central sulcus rostrally (in front)
 * postcentral sulcus caudally (in back)
 * lateral sulcus inferiorly (underneath)

Brodmann area 3 is divided into 2 areas : area 3a and area 3b.

Connection and functions of the subdivisions also mechanism
Brodmann area 3 receive most of the somatosensory input from the thalamus, area 3b is primarily concerned with basic processing of touch sensations, and area 3a responds to the inputs form proprioceptors.

Area 3b is densely connected to areas 1 and 2, and when area 3b receives touch information, that information is then send to areas 1 and 2 for more complex processing. Area 2 is also involved with proprioception.

Function
The primary somatosensory cortex processes information of :
 * Touch
 * Proprioception
 * Pain
 * Temperature

Somatotopic arrangement
The primary somatosensory cortex is arranged such that specific area correspond to specific regions in the human body. More sensitive regions in the body have larger brain area.