Other Senses

Touch, Proprioception, Taste, Smell

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

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

Pain

• Icky but necessary• Combination of bottom-

up and top-down• Varies from person to

person

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!

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.).

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

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

End of Sensation