somatosensorische

Somatosensorische perception, in English the somatosensory system, refers to the sensory processes that produce conscious awareness of body sensation. It encompasses tactile sensation, proprioception, nociception (pain), and thermoreception, integrating information from the skin, muscles, tendons, joints, and internal organs.

Peripheral reception and transmission: sensory receptors transduce mechanical, thermal, and chemical energy into electrical signals carried by primary afferent neurons that enter the central nervous system through dorsal roots or cranial nerves for the head and face. The signals reach the thalamus, primarily the ventral posterior nucleus (VPL for the body and VPM for the face), and then project to the cerebral cortex.

Cortical representation: the primary somatosensory cortex (S1) in the postcentral gyrus processes basic features such as touch, pressure, and positional sense, organized across a somatotopic map known as the sensory homunculus. Secondary somatosensory cortex (S2) and related association areas integrate with motor planning and multisensory perception, contributing to object recognition and tactile memory.

Pathways: discriminative touch and proprioception travel via the dorsal column–medial lemniscus pathway; pain and temperature travel via the spinothalamic tract and related routes. A parallel system, the trigeminal pathway, conveys somatosensation from the face to the thalamus and cortex.

Clinical relevance and development: the somatosensory system exhibits plasticity after injury, with recovery dependent on age and extent of damage. Lesions can cause sensory loss, paresthesias, agnosias, or central pain; rehabilitation may include sensory retraining and multisensory integration therapies.