Somatosensory System: Neural Basis of Touch Perception

The somatosensory system mediates tactile perception. It comprises:

• Peripheral receptors in skin – detect touch, pressure, vibration, temperature, pain.
• Afferent nerves – transmit signals via dorsal root ganglia to spinal cord.
• Ascending pathways – dorsal column-medial lemniscus (fine touch, proprioception) and spinothalamic (pain, temperature).
• Thalamus – relays to primary somatosensory cortex (postcentral gyrus).
• Cortical processing – generates conscious tactile experience.

This integrated pathway enables discrimination of texture, shape, temperature, and noxious stimuli.