Other Senses

1. Other Senses Touch, Proprioception, Taste, Smell

2. Touch • Vital for development • Receptors located in our skin. • Sense of touch is actually mixed senses – pressure, warmth, cold or pain • Only pressure has identifiable receptors • Brain more sensitive to unexpected stimulation • This is why we cannot tickle ourselves • Top down and bottom up

3. Kinesthesis/Vestibular Sense • Kinesthesis is your sense of the position and movement of your body parts • Vestibular sense – monitors your body’s head • Sense of equilibrium • Vestibular sacs in ears connect the canals with the cochlea and contain fluid that moves when your head rotates or tilts. • Movement stimulates hair-like receptors that send messages to cerebellum • Enables us to sense body position and maintain balance

4. Pain • Icky but necessary • Combination of bottom-up and top-down • Varies from person to person

5. Gate Control Theory • No one stimulus that triggers pain nor one definable area of the brain • Different nociceptors that detect hurtful temperatures, pressure of chemicals • Spinal cord has a neurological “gate” • When a tissue is injured small fibers activate and open the gate and you feel pain • Large fiber activity shuts the gate and blocks signals from reaching the brain • Brain to spinal cord messages can also close the gate – distraction, release of endorphins • Pain is bio-psycho-social!

6. Taste • Evolutionary – protection purpose – aversive tastes deterred eating toxins- toddlers are fussy eaters • We have bumps on our tongue called papillae– taste buds • Each bum on tongue has 200 or more taste buds • Chemical sense • Specialized receptors for: sweet, salty, sour, bitter and umami. • Umami? • Savory! • Specifically receptors for glutamate • Fish, shellfish, cured meats, vegetables (e.g., mushrooms, ripe tomatoes, Chinese cabbage, spinach, celery, etc.) or green tea, and fermented and aged products (e.g., cheeses, shrimp pastes, soy sauce, etc.).

7. Sensory Interaction • Experiment time! • Need 2 BRAVE volunteers who have strong little tummies! • Sensory Interaction! • The principle that one sense may influence another as when smell if food influences its taste

8. Smell • Sense of smell is olfaction • Chemical sense • 5 million (or more) receptor cells at top of each nasal cavity • Receptors respond selectively • Alert brain through axon fibers • Bypass thalamus • Associate memories with smells • Smell is primitive

9. End of Sensation