Sensory Neuroscience

Somatosensory System

The sensory system responsible for the perception of touch, pressure, pain, temperature, position, movement, and vibration, originating from muscles, joints, skin, and fascia.

Cutaneous Senses

The perception of touch and pain from stimulation of the skin.

Proprioception

The ability to sense the position of the body and limbs.

Kinesthesis

The ability to sense movement of the body and limbs.

Epidermis

The outer layer of the skin, composed of dead skin cells.

Dermis

The inner layer of the skin, containing mechanoreceptors that respond to stimuli such as pressure, stretching, and vibration.

Mechanoreceptors

Sensory receptors in the skin that respond to mechanical stimuli such as touch, pressure, and vibration.

Merkel Receptor

Disk-shaped receptor near the epidermis/dermis border, responsible for fine touch and pressure.

Meissner Corpuscle

Stack of flattened disks in the dermis, detecting light touch and vibration.

Ruffini Cylinder

Branched fibers inside a cylindrical capsule, responding to skin stretch.

Pacinian Corpuscle

Onion-like capsule deep in the skin, detecting high-frequency vibrations.

Rapidly Adapting (RA) Fibers

Found in Meissner and Pacinian corpuscles, firing at stimulus onset and offset.

Slowly Adapting (SA) Fibers

Found in Merkel and Ruffini receptors, firing continuously while pressure is applied.

Medial Lemniscal Pathway

Large fibers carrying proprioceptive and touch information.

Spinothalamic Pathway

Smaller fibers carrying temperature and pain information.

Somatosensory Cortex (S1 & S2)

Brain areas in the parietal lobe responsible for processing sensory information.

Homunculus

A cortical map showing the proportion of sensory representation for different body parts.

Cortical Plasticity

The brain’s ability to reorganize and adapt based on sensory experience, such as after amputation.

Phantom Limb Syndrome

The perception of a missing limb’s presence, often accompanied by pain due to cortical reorganization.

Gate Control Theory of Pain

A model suggesting that pain perception is regulated by a 'gate' in the spinal cord that modulates nociceptive signals.

Pain Matrix

A network of brain regions involved in processing pain, including the somatosensory cortex, insula, and anterior cingulate cortex.

Endorphins

Neurotransmitters that act as natural painkillers by binding to opiate receptors.

Placebo Effect

The phenomenon where a person experiences pain relief due to the belief that they received treatment.

Haptic Perception

Active touch used to explore objects, combining sensory, motor, and cognitive systems.

Five Basic Tastes

Salty, sour, sweet, bitter, and umami.

Chorda Tympani Nerve

Transmits taste information from the front and sides of the tongue.

Glossopharyngeal Nerve

Transmits taste information from the back of the tongue.

Vagus Nerve

Transmits taste signals from the mouth and throat.

Olfactory System

The sensory system for smell, involving olfactory mucosa, olfactory bulb, and piriform cortex.

Olfactory Mucosa

The area in the nasal cavity containing sensory neurons.

Olfactory Bulb

Processes smell signals before relaying them to the brain.

Piriform Cortex

The primary olfactory processing area in the temporal lobe.