TheOther Senses

Taste, Smell, Touch, and Others

Taste

• Taste cells are chemical-sensitive receptors located in taste bud clusters– Located on tongue, in

throat, and on soft palate

• For a stimulus to be tasted, it must be dissolved

• Receptors are sensitive to five basic taste qualities:– Sweetness– Saltiness– Sourness– Bitterness– Umami• Discovered in 2009

Taste

Taste

• Other influences on taste:– Smell– Touch– Temperature

• It is possible to demonstrate how the flavor of food can be changed by the food’s texture or smell– Jellybean experiment

Taste Map?

• Appears in high school textbooks

• Science shows map is incorrect

• Receptors for basic tastes are found in distinct cells not confined to any specific region

http://www.nytimes.com/2008/11/11/health/11real.html?_r=0

Smell• Receptors for smell located

on a thin membrane found in the upper nasal cavity.– Stimulated by gasses

dissolved in the fluid covering the membrane

– For a stimulus to be smelled, it must be dissolved

– Carry information to the prefrontal cortex

Smell• Odors can evoke highly

emotional memories.• On average, women detect

odors more readily than men.– Brain responses to odor are

also stronger• Humans capable of

discriminating the gender of sweaty shirts and even breath odor.– Commercial fragrances?

Not so much.

Pheromones• Airborne molecules

that elicit a reaction in the same species

Sneezing• Your body’s way of removing

irritation from the nose.• Nose gets a “tickle” sends

message to special part of brain called the sneeze center.

• Sneeze center sends message to multiple muscles to work together to remove irritation.– Abs, pecs, diaphragm, vocal

cord, throat muscles, eyelid muscles.

• Particles leave nose at ~100mph

http://kidshealth.org/kid/talk/qa/sneeze.html

Sneeze in the sun?• You’re a photic

sneezer!

• 1 out of every 3 people sneeze when exposed to bright light

• Inherited trait

Achoo.

Gesundheit.

Somosthesis—The Mechanical Senses