cgs 2301 - chemical senses

chemical senses

taste and smell

mechanical senses

vision, audition, and touch

gustation (taste) function

not eating things that will kill you

order of structures

• bumps (papillae) contain taste buds

• taste buds house taste receptor cells

• microvilli react to tastant molecules

• top to bottom: taste pore, microvilli, taste receptor cell, nerve fibers

five categories of tastants

sweet, sour, salt, bitter, and umami

note: contrary to popular belief diff region of the tongue don’t correspond with diff tastants → all taste receptors can detect all five basic types of taste

anatomy of papillae

• front to back of mouth:

• circumvallate papillae: more sensitive to bitter

• foliate papillae: more sensitive to sour

• fungiform papillae

• fillform papillae: lot of them, don’t have any taste buds, detect texture not taste

olfaction function

smell

social behaviors and survival (if something is safe, like smell smoke or poison)

olfactory pathway

• odorants dissolved by olfactory epithelium (a structure)

• olfactory receptor neurons turn chemical info into info our brain can understand, then send info to glomeruli in olfactory bulb

• olfactory bulb transmits info to olfactory cortex

• info goes directly from nose to brain

• mnemonic: Every Red Nose Braves Cold

axons project to which areas?

long term memory

limbic system (memory, emotions)

this is why emotional memories can associate w smells

how does smell relate to social behavior?

PET scan study w hetero men, homo men, and hetero women presented with testosterone based odorant

significant activation in hypothalamus for hetero women and homo men