olfalatory and gustation

whats olfaction?

sense of smell

what does olfaction detect?

detect of chemicals in the air (ordorants)

what do humans use olfaction for?

identify food and quality of food (should I approach or avoid something in the environment?)

what can odorants do?

volatile (be able to float in the air) & are very small

what is the sensory organ of smell?

olfactory epithelium

where is the olfactory epithelium located?

inside the nasal cavity

what is the olfactory epithelium lined with?

olfactory receptor neurons which detect odorants that reach into the nasal cavity

when do olfactory neurons die off after about so the epithelium creates new ones?

a month

what routes do odorants reach the olfactory epithelium by two routes?

orthonasal olfaction and retronasal olfaction

what is the orthonasal olfaction?

odorant goes through the nostril

what is the retronasal olfaction?

odorant goes through the mouth and then nasopharynx (top of the throat) and then the nostrils

what other areas of the brain do odorants pass by?

amygdala, entorhinal cortex & hippocampus, piriform cortex

olfaction is the only sense that isnt processed in the?

thalamus

by what does the anterior (front) piriform cortex organize odorants?

chemical structure

by what does the posterior (back) piriform cortex organize odorants?

perceptual similarity

top down olfactory perception says that expectation and experience influences?

odor perception (expecation) and perception (experience)

what is ansomia?

inability to perceive smell

what can failing to sense smell be a warning sign of?

alzheimer

what is hyperosmia?

when smelling is enhanced; increase in olfactory sensitivity

who is typically better at discriminating odors?

women

what is gustation?

sense of taste that detects chemicals dissolving on our tongue

what are the 5 basic tastes of gustation?

sweet, sour, salty, bitter, umami

what do humans use gustation for?

identify food and quality of food such as ions (salty), energy (sweet), building blocks for proteins; amino acids (umami), bacteria/spoiled food (sour), toxic chemicals (bitter)

do we have a taste map on our tongue?

no

what is the tongue covered in?

papillae

what is embedded in the papillae?

taste buds that contain taste receptor cells

what do the receptor cells react to?

sweet, umami, bitter

what is the presynaptic cells?

salty, sour

salty and sour tastants are?

positively charged ions

where do salty and sour tastants pass through?

ion channels and depolarize the taste cell cause an action potential

sweet and bitter tastants are?

sugars and other chemicals

what is activated from the sweet and bitter tastants?

G-protein coupled receptors that trigger events within the cell that eventually lead to depolarization and action potential

what do presynaptic (sour) cells react to as well?

carbonation and water

what are the pathways to the cortex?

Vagus Nerve (CN X), Glossopharyngeal Nerve (CN IX), Chorda Tympani Nerve (branch of facial nerve: CN VII)

the higher the concentration of a tastant means?

the more intense the taste

what is the quality of taste more likely coded by?

pattern of multiple neurons

what is the in the brain?

experience of taste

what influence taste perception?

adaptation, temperature, mouthfeel, visual, and auditory

gustation is carried to w here?

Carried to the brain via 3 cranial nerves

after gustation is carried to the brain via 3 cranial nerves, where does it go?

Nucleus of the solitary tract (medulla; midbrain)

where does the nucleus of the solitary tract carry gustation to?

 thalamus

where does the thalamus take gustation to finally?

insular cortex (primary gustatory cortex)

whats tip of the nose?

when you recognize an odor but cannot name it

what does the new taste receptor located in the foliate papillae react to?

fat

capsaicin binds what?

temperature detectors on our tongue to perceive heat

what is ma spicy lead to?

sensation of numbness and activates tactile receptors in the mouth