1. Other Important Senses: Touch, Taste, and Smell
Chapter 5
Other Important Senses: Touch, Taste, and Smell

2. Touch Essential for development
Skin = the largest sense organ body — allows for touch; detects pressure
Most sensitive – fingers, lips, cheek, foot, & forehead
Least sensitive – belly, upper arm, shoulder, thigh, & calf
Sense of touch has 4 basic sensations:
1. Pressure
2. Pain
3. Warmth
4. Cold

3. Pain Pain experiences can be:
Tells you something is wrong – change behavior
Pain experiences can be:
Biological- Nerve fibers sending info to the brain
Psychological- Situation and our past experiences
Social-cultural- Cultural expectations/presence of others

4. Pain is in the brain
Lamaze classes teach women the technique of distraction during childbirth
7-10 amputees feel pain in their non-existent limb (phantom limb)
Occurs also with hearing, sight, taste & smell losses.

5. Gate Control Theory
Gate-Control Theory- spinal cord contains a “gate” that either blocks pain signals or allows them to pass to brain
Rub area around pain to stimulate “gateclosing” activity.
Release of endorphins (neurotransmitters)
natural painkiller

6. Body Position and Movement
Kinesthetic Sense (Kinesthesis) monitors and coordinates movement among body parts through information sent from sensory neurons (proprioceptors)
Allows to be aware of movement without actually seeing limb move.

7. Vestibular Sense - Sense of Balance
Vestibular Sense monitors head position and balance.
Fluids in the inner ear (vestibular sacs & semicircular canals) help to maintain your equilibrium.
Semicircular Canal - Pretzel like canals holding fluid which are connected to the cochlea.
Allows us to sense our body position and to maintain balance by moving when the head rotates or tilts.
MAIN CAUSE OF MOTION SICKNESS

8. Taste - Gustation Taste Buds - sensory receptors located on tongue
Taste is a chemical sense
As you grow older taste buds decrease (Smoking & alcohol use accelerate the decline)
Believed genetics predispose us to certain taste
Taste receptors reproduce every week or so

9. Taste - Gustation
Traditionally, taste sensations consisted of sweet, salty, sour, and bitter tastes. Recently, receptors for a fifth taste have been discovered called “Umami.” All other tastes are a mixture.
Preview Question 11: How do we experience taste?
Sweet
Sour
Salty
Bitter
Umami
(Fresh
Chicken)

10. Taste - Gustation All other tastes are mixtures
Taste buds contain a pore that catches food chemicals. Molecules are then sensed by taste receptor cells.
Taste receptor cells project antenna-like hairs into pores
Taste receptors reproduce themselves every week or two

11. Sensory Interaction
When one sense affects another sense, sensory interaction takes place.
Smell plus texture plus taste equals flavor
In interpreting the world, the brain blends the inputs of a senses.

12. Smell – Olfaction (Chemical Sense)
We smell something when molecules of a substance carried in the air reach a tiny cluster of million receptor cells at the top of each nasal cavity.
Olfactory receptor cells in nasal cavity wave around and respond selectively to alert the brain
Olfactory Bulb - smell is registered and converted into neural messages

13. Olfactory nerves
Olfactory Tract- takes information to different parts of brain
Limbic System emotional significance is associated
Temporal Lobe - recognition of smells
Smell does not go to the thalamus like the other senses.

14. A few last notes on smell
Attractiveness of smells depends on learned associations
Odors have the power to evoke memories and feelings