Sensation: Touch and Kinesthesia

Sensation: Touch

• Touch allows us to feel pressure, pain, and temperature
• Touch signals are managed by neurons in the peripheral nervous system
• These neurons react to pressure, temperature, and chemical changes
• The brain interprets these signals as pressure, pain, or temperature
• Pain is triggered by nociceptors, which are activated by temperature, pressure, or chemicals
• Pain signals are managed by a "gate-control" system
• Small pain fibers constantly send signals to the brain, while large fibers block these signals
• Large fibers allow pain signals to reach the CNS (central nervous system) and brain when stimulated
• Phantom limb pain can occur due to large fibers failing to block constant pain signals, or errors in the brain's association areas

Sensation: Kinesthesia

• Kinesthesia is our sense of body position and body parts
• This allows coordinated movement without visually checking body parts
• Kinesthesia is related to our vestibular sense, which tracks head position and movement
• Balance is maintained by semicircular canals and vestibular sacs in the inner ear
• These structures contain fluid that shifts in response to head rotations or tilts
• Hair-like receptors within these structures detect the fluid shift
• This triggers signals to the cerebellum, which processes balance and stability