Lecture 23: The PNS- Somatic Sensation Flashcards
Four parts of somatic sensation
Touch, temperature, nociception (pain + itch), proprioception
What is the area of somatosensory cortex devoted to a specific body area associated with?
Sensitivity
Plasticity
Amount of area for a specific body part can change in size
Places with thermoreceptors with free nerve endings
Skin, organs, muscles, CNS
Nociceptors
Respond to strong noxious stimuli
chemicals, mechanical damage, thermal extremes
Nociceptors are localized throughout the body except for what nervous system?
CNS
What is nociception felt as?
Pain or itch
Fast Pain
Pricking, sharp pain
Small myelinated axons (make it fast)
Slow Pain
Dull, achy
Small unmeyelinated axons (make it slow)
Itch
Linked to pain in that scratching and itch can reduce the perception of pain
Associated with rashes, MS, and diabetes for example
When is nociception increased?
Emotional experience
When is nociception inhibited?
Higher order functioning
Gate Control Theory
Stimulating mechanoreceptor fibers (rubbing the skin) inhibits other pathways, decreasing the sensation of pain
Kinesthesia
Body movement
What do different neurons encode?
Limb/ joint velocity, load, muscle length