Touch Receptors in the Skin

Touch Receptors

Touch receptors in the skin provide tactile information about:

• Position
• Shape
• Texture
• Pressure
• Movement

Receptor Adaptation

Touch receptors are classified by adaptation speed:

• Rapidly Adapting Receptors:
  • Activated upon initial stimulus encounter.
  • Fall silent if the stimulus persists.
  • Detect movement.
• Slowly Adapting Receptors:
  • Respond continuously to a persistent stimulus.
  • Detect size and shape of objects.

Receptive Field Size

Touch receptors also vary in the size of their receptive field. Smaller receptive fields allow for better tactile discrimination.

Types of Touch Receptors in Hairless Skin

Merkel's Discs

• Slowly adapting receptors.
• Small receptive fields.
• High spatial resolution.
• Dense in fingertips.
• Shape and texture processing.

Meissner's Corpuscles

• Rapidly adapting receptors.
• Relatively small receptive fields.
• Spatial resolution is inferior to that of Merkel's discs.
• Transmit information about movement between the skin and another surface.
• Sense texture.
• Detect the sliding of objects past the skin (important for maintaining grip).

Pacinian Corpuscles

• Rapidly adapting receptors.
• Large receptive fields.
• Transmit information about vibrations caused by contact or grasping.
• Important for tool use.

Ruffini's Endings

• Slowly adapting receptors.
• Large receptive fields.
• Poorly understood.
• Respond to skin stretching.
• Awareness of finger and hand position.