1. Touch, Taste, Smell

2. Touch is essential to development
Premature babies gain weight faster when given massages
Infant rats deprived of mothers’ grooming touch have stunted growth
Monkeys deprived of mothers touch are traumatized

3. Sense of Touch
Combination of four skin senses: pressure, warmth, cold and pain
Controlled by somatosensory cortex in parietal lobes
Sensitivity varies between body parts

4. How do we sense pain? Gate-Control Theory
There are pain gates in the spinal cord (open=pain, closed=no pain)
Different types of stimulation cannot be sent through the gates simultaneously
Conflicting stimulation closes the gate
Acupuncture, ice, rubbing

5. Pain Control Pain can be treated both physically and psychologically
-relaxation, distraction
-Lamaze, hospital study (Ulrich 1984)

6. Sense of Smell Olfaction
Receptor cells in the olfactory membrane transduce chemicals from the air
Olfactory bulb has a direct link to limbic system (memory and emotion) through olfactory nerve
Pheromones chemical messengers processed through smell

8. Sense of Taste Gustation: transducing chemicals from food
Gustatory (taste) receptor cells found in taste buds
taste buds embedded in papilla (bumps) across the tongue sense all flavors
5 types of taste buds (sweet, sour, salt, bitter, umami (savory)
Flavor=smell+taste
Why did we develop a sense of taste?

9. Each bud contains elongated taste cells that respond to sweet, salty, sour, bitter or umami (savory).

10. Kinesthetic Sense
Tells the brain where the parts of the body are relative to one another
Controlled by sense receptors on the joints and muscles
damage=apraxia: inability to manipulate objects

11. Vestibular Sense
Tells the brain about the position of the head relative to the body and ground/aids in balance
Controlled by fluid-filled sacs in the semicircular canals of the inner ear
Connects to cerebellum and eyes