Chapter 5 Part 3 Flashcards
Tactile
Meaning touch
First step of touch
Tactile receptors respond to touch and pressure and send information to the spinal cord
Second step of touch
The information is relayed to the thalamus
What types of tactile stimuli exist?
Rewarding and bad tactile stimuli
Like stroking a baby’s cheek
Ruffini’s End Organs
a type of sensory receptor that responds to heavy pressure and movement of joints
Merkel’s discs
Understand information of light to moderate pressure on the skin
Free Nerve Endings
Located on the surface of the skin
Primary function is to detect touch, pain, pressure, and temperature
Meisnner’s Corpuscles
Understand the information from sensitive touch in hairless regions of the body
Pacinian Corpuscles
located deep in the skin that responds to vibration and heavy pressure
Which area has more free nerve endings?
Areas of the skin that are more sensitive
What happens if you are touched or being touched?
The free nerve endings send tactile information to the spinal cord
Then the spinal cord sends the information to the brain
Next it goes to the thalamus, and finally sent to the soma sensory cortex located in the parietal lobe
How are painful sensations sent?
Through free nerve endings to the brain
How can pain information travel to the brain?
Two different systems
Fast Pathway
uses myelinated axons to transmit information quicker
Assists with using our reflexes after experiencing immediate pain
Slow Pathway
uses more unmyelinated axons to transmit information about processing emotions
Gate Control Theory of Pain
Created by Canadians, Ronald Melzack and Patrick Wall
Suggested that certain neural activity create a gate to block pain signals from being sent to certain parts of the brain
What do earlier versions of the Gate Control Theory suggest?
Suggested that pain signals were blocked from being sent to the spinal cord
Later studies show that individuals have differences in blocking out pain signals depending on their sensitivity to pain
Touching the affected area can automatically create a gate that can relieve the pain
What is the most common tactile sense disorder?
Chronic Pain or pain that lasts longer than 3 months
Results from abnormal adaptation in the somatosensory cortex
Which two chemicals have pain-relieving properties?
Endorphins and Enkephalins
Belong to a class of molecules called opiates
Opiates are released by neurons after an intense physical activity, stress, and sexual experience
Why is pain sensation important?
critical for physical survival
You would not be able to relieve the pressure on your skin, which can develop sores and bruises.
No pain (familial dysutonomia)
rare genetic condition associated with an inability to detect pain or temperature and produce tears
Phantom Limb Sensations
Tactile hallucinations of touch, pressure, vibration, and pain in the body part that no longer exists
Third Step of Touch
The thalamus sends the information to the somatosensory cortex
