1. Aim: What factors influence our sensitivity
Aim: What factors influence our sensitivity? What role does the mind and body play in pain perception?
DO NOW:
HW:
Read “What You See is What You Have Learned” p. 7 – 10 and questions on p. 6

2. The Skin Senses skin – largest sensory system
cutaneous senses (3 types of receptors)
touch (mechanical energy / pressure against skin)
temperature
thermoreceptors – sensory nerve endings under the skin that respond to changes in temperature at or near the skin and provide input to keep the body’s temperature at 98.6 degrees Fahrenheit (heat = dominant)
pain (adaptive for survival; intense stimulation of any sense produces pain)
prostaglandin – stimulate receptors that cause the experience of pain (many painkiller reduce production)
fast pathway  thalamus (fast response required)
slow pathway  detour in limbic system (tells you to “slow down” your lifestyle – “nagging pain”)

3. Sense of Touch You will perform a 2 pt. threshold test on 1 partner.
Randomly use all 4 tips to test the sensitivity of THREE parts.
Record data on p.

4. Sensitivity Threshold
Receptors located on skin
Activated by energy
Various parts of body differ in sensitivity
Crucial features are more sensitive

5. What is the Gate Control Theory of Pain?
What other factors influence pain?

6. Factors which can impact pain reception?
endorphins – neurotransmitters (slow pathway)
factors: motivation, expectation, decision factors
women experience more pain

7. Gate Control Theory
Brain controls our gate and our thoughts and feelings can influence pain
some pain message receive higher priority than other messages
higher priority let in and lower priority shut out!
What was the old accepted view of the perception of pain?
What is the gate control theory? What influences pain according to this theory?
2 - minutes

8. Ramachandran’s Mirror Trick
Phantom Limb
Ramachandran’s Mirror Trick
Amputated body part but might still have feeling in the area
Theories
Brain is undergoing extensive sensory reorganization
Revised Gate Control

9. How can we apply this to pain management?

10. Taste
sweet, sour, bitter, salty + umami or yummy or savory (L-glutamate)
papillae – round bumps above the tongue's surface that contain the taste buds, the receptors for taste (replaced every two weeks)
10,000 taste buds (younger)
5,000 taste buds (older)
Role of culture on taste perception
20% of us are super tasters (more taste buds)!
Taste preferences begin in womb

11. Interaction of smell and taste
Work with partner.
6 trials with eyes closed & using nose– have them identify
6 trials eyes closed and NO NOSE – have them identify

12. Smell/ olfactory
olfactory epithelium – the lining of the roof of the nasal cavity, containing a sheet of receptor cells for smell
unique: neurons replace themselves after injury; don’t pass through thalamus
 temporal lobes  various brain regions (including limbic system – linked to emotion and memory (LOVE!)
Dog times lower levels

13. Kinesthetic Sense (MOP) – movement, orientation, posture
not in specific organ; receptors embedded in muscle fibers and joints
same pathways to brain as touch
Tells us where our body parts are.

14. Vestibular Sense (MB) – movement and balance
begins in auditory nerve, which contains both cochlear nerve and vestibular nerve for balance and movement
vision used in addition (when everything in visual field is moving… generally WE are moving
proprioceptive feedback – information about the position of our limbs and body parts in relation to other body parts
Receptors in semicircular canals of inner ear – three fluid-filled circular tubes that lie in the three planes of the body
right-left
front-back
up-down

15. Aim: How do we perceive the world through touch and taste?
Do Now:
What factors influence our perception of pain?
Homework:
Test Monday on Sensation and Perception ( Study Guide Due)