1. Touch, Taste, Smell, Balance http://learn.genetics.utah.edu/c ontent/senses/touch/

2. Touch  Touch receptors are on the skin  Skin is the largest & heaviest organ (20 sq. ft. & 6 lbs.)  Organ: several types of tissues functioning together, so yes it’s an organ  All skin sensation if a combination of:  Pain, warmth, cold, and pressure

3. Why Can’t I Tickle Myself?  Brain is more sensitive to unexpected stimulation  Produces less sensory cortex activation when you do it to yourself

4. Taste  Bumps on your tongue are called papillae; CAN SEE  Tucked inside are tiny nerve endings (taste buds) CAN’T SEE  Each taste bud is sensitive to one flavor  Five different tastes:  Salty, sweet, sour, bitter & umami (meaty flavor)  Spicy is not a flavor, it triggers pain receptors in our mouth Spicy  Taste buds are replaced weekly  3 ways to permanently kill taste buds  Receptor sends info to thalamus  In order to taste, we must be able to smell!

5. Sensory Interaction  When one sense influences another sense!

6. Smell  5 million cells in each nasal cavity  Olfactory bulb gathers messages but DOES NOT SEND IT TO THE THALAMUS!!!!  Instead of thalamus  Nerve fibers from olfactory bulb connect to amygdala and then the hippocampus  That’s why odors evoke memories and feelings! Sensory adaptation Who is more sensitive? Men or women?

7. Kinesthetic Sense  Sensing the position & movement of individual body parts  muscles and joints  Balance  Semicircular canals.  Fluid movement=dizzy feeling Vestibular Sense

8. What purpose does pain serve?  Body’s way of telling you something is wrong. CHANGE YOUR BEHAVIOR IMMEDIATELY  Pain travels up your spine  You will not feel pain until it is processed by the brain (reflex)  Some people naturally have more endorphins than others  External stimulus  Internal stimulus

9. Sensation of pain depends on:  Physiology  Experiences  Attention  Why do we rub around the area?  Presence of others  Since pain is in the brain, diverting the brain’s attention brings relief