Neuroscience in Occupational Therapy: Somatosensory System

Vocabulary flashcards covering the somatosensory system, cutaneous and proprioceptive receptors, ascending pathways, dermatomes, sensory assessment procedures, and OT clinical reasoning.

Somatosensation

The nervous system's detection of touch, pressure, vibration, pain, temperature, and proprioception.

Sensory Processing

How the central nervous system organizes, modulates, integrates, and responds to sensory information.

The OT Sensory Reasoning Model

A four-step clinical reasoning framework: Sensory function $\rightarrow$ Sensory finding $\rightarrow$ Occupational consequence $\rightarrow$ OT assessment + intervention.

Meissner's corpuscles

Cutaneous mechanoreceptors that detect light touch.

Merkel's disks

Cutaneous mechanoreceptors that detect sustained pressure and tactile discrimination.

Pacinian corpuscles

Cutaneous receptors that detect deep pressure and vibration.

Ruffini endings

Cutaneous receptors that detect skin stretch.

Cutaneous Receptors

Specialized sensory nerve endings located across the epidermal and dermal layers—including Meissner's corpuscles, Merkel's disks, Ruffini endings, Pacinian corpuscles, Krause end bulbs, and free nerve endings—that detect tactile, thermal, and painful stimuli.

Muscle spindles

Proprioceptive receptors that detect muscle stretch and the rate of change in length.

Golgi tendon organs

Proprioceptive receptors that detect muscle tension.

Joint receptors

Proprioceptive receptors that detect joint position and movement extremes.

Nociceptors

Sensory receptors that detect potentially damaging mechanical, thermal, or chemical stimuli.

A-delta fibers

Myelinated sensory fibers that transmit fast, sharp, and localized pain.

C fibers

Unmyelinated sensory fibers that transmit slow, burning, and diffuse pain.

Thermoreceptors

Sensory receptors that detect changes in skin temperature, providing essential protective sensation during tasks like cooking and bathing.

DCML Pathway

The Dorsal Column-Medial Lemniscal pathway carries fine touch, vibration, and conscious proprioception; it decussates in the medulla and projects through the thalamus to the somatosensory cortex.

Spinothalamic Pathway

The ascending sensory pathway that carries pain and temperature sensation; it decussates in the spinal cord and projects through the thalamus to the somatosensory cortex.

Spinocerebellar Pathways

Ascending neural tracts that carry unconscious proprioceptive information to support coordination, postural control, and motor learning.

Sensory Homunculus

A neurological map of the somatosensory cortex where body parts with greater receptor density and sensitivity—such as the hands and lips—have disproportionately larger cortical representations.

Dermatome

A specific cutaneous skin region innervated by a single spinal nerve or root (e.g., C6 supplies the thumb, T4 supplies the nipple line, and L5 supplies the great toe).

Stereognosis

The ability to identify and recognize familiar objects through touch and manual manipulation without the use of vision.

Sensory Detection

The ability to recognize the presence of a sensory stimulus, answering the fundamental question: 'Can I feel something?'

Sensory Discrimination

The ability to discern, interpret, and locate the characteristics of a sensation, answering: 'What is it? Where is it? What does it feel like?'

Documenting Sensory Findings

The standardized four-part formula for clinical recording of sensory function: Modality + Location + Response + Comparison.

Sensory Re-education

A restorative intervention approach that uses graded sensory stimulation and practice to improve or retrain sensory function.

Sensory Compensatory Strategies

Interventions used when sensory recovery is limited, focusing on visual compensation, environmental/task modifications, and safety education to prevent injury.