7.3 Taste and Smell

Chemoreceptors respond to the presence of specific _____________ in the environment

molecules

In vertebrates, chemoreceptors form parts of receptor organs for ___________ and _____________

gustation and olfaction

The _________ are specialized regions on the tongue

papillae

Filiform (papillae) is ________-shaped and provides a ____________ surface for food ____________

filament; rough; manipulation

Vallate is the ___________ and least numerous papillae. there are __-__ in a V shape along border between anterior and posterior parts of the tongue.

largest; 8-12

Fungiform is ___________-shaped and scattered irregularly over the ___________ surface of the tongue

mushroom; superior

Foliate is ______-shaped and is located in folds on the __________ sides of the tongue. Foliates contain the most __________ taste buds and decrease with ____

leaf; outer; sensitive; age

insert tongue pic

Taste buds are supporting cells surrounding ______________ cells and they detect __________

gustatory; taste

Taste cells have microvilli that are replaced about every ____ days

10

Taste receptors detect __________ from food that come into contact with the receptor

molecules

What are the five taste types?

sweet, salty, bitter, sour, umami

Substances called "_________" which are dissolved in ______ enter the taste ________

tastants; saliva; pores

By varying mechanisms depending on __________, tastants cause the taste cells to __________

taste; depolarize

Sour tastes have the most _____________ receptors on _________ aspects of the tongue. The ____ ions of acids cause depolarization

sensitive; lateral; H+

Salty tastes have the most sensitive receptors on the _____ of the tongue. Anything with ____ ion causes depolarization

tip; Na+

Bitter tastes have the most sensitive receptors on the ___________ aspect of the tongue. ____________ which are toxic, produce the bitter sensation

posterior; alkaloids

Sweet tastes have the most sensitive receptors on the _______ of the tongue. __________ and some _________ give the sweet flavor

tip; sugars; proteins

Umami has _________ sensitivity and it caused by ________ ______ binding to receptors

scattered; amino acids

Which tastes are the least sensitive?

sweet and salty

Which taste is the most sensitive?

bitter

insert actions of major tastes

_____, ________, and ______ use a G protein mechanism for depolarization

sweet, bitter, umami

Sour has _____ different mechanisms for depolarization

3

Salty uses _____ channels for depolarization

Na+

____________, __________ and __________ affect the perception of taste

texture, temperature, smell

Axons of sensory neurons which synapse with ________ receptors pass through cranial nerves ___, ___ and ___ and the ________ of each nerve

taste; 7, 9, 10; ganglion

Axons of sensory neurons enter the brainstem and synapse in the nucleus of the _________ _______, then travel to the ___________ and then travel to the _______ area of cortex

tractus solitarius; thalamus; taste

The olfactory receptive neurons are _________ neurons that have dendrites with ______ that protrude into the mucus covering olfactory epithelium and have axons synapse with _________ cells in olfactory ______

bipolar; cilia; mitral; bulb

The olfactory bulb has axons from olfactory neurons organized in ________ and functions to filter ________

clusters; odors

The olfactory tract has axons of afferent neurons of olfactory _____ that connect to several regions of the brain including the __________

bulb; amygdala

Each olfactory receptor cell expresses _____ type of olfactory ________ that can respond to a set of _________ odorants

one; receptor; different

Axons of olfactory receptor cells with the ______ type of receptor ________ and form synapses with ________ cells in structures called ___________ which are located in the olfactory bulb

same; converge; mitral; glomeruli

_______ axons synapse with a ______ mitral cell

multiple; single

Mitral cell _______ comprise the olfactory ______ and send AP to various spots in the brain

axons; tract

The avg person can recognize more than ________ diff odors

4000

Dendrites of olfactory neurons have enlarged ends called __________ _________

olfactory vesicles

Olfactory bulbs also connect to ________ system, and the signals can elicit __________ response

limbic; emotional

Smell information goes to the olfactory ________ without going through __________

cortex; thalamus

The three regions in the frontal lobe that affect smell and interact with the _______ system are the _________, ___________, and __________ olfactory areas

limbic; lateral, medial, intermediate

The lateral olfactory area controls the ___________ perception of smell

conscious

The medial olfactory area controls the _________ and ________ reactions to odor

visceral and emotional

The intermediate olfactory area effects ___________ of ____________ information

modification; incoming

Vaporized molecules from ________ are transmitted from the throat to ___________ receptors in __________ cavity

food; olfactory; nasal

Thermoreceptors have ______ nerve endings at the bodies __________

free; surface

Nociceptors detect stimuli that can _________ body tissue and are located on the surface and interiorly. info from these result in sensation of _______

damage; pain

Glutamate releasing axons are used if pain is ______ or __________

sharp or localized

Substance P releasing axons are used if pain is _____, _________, or not well localized

dull, aching

Released endorphins bind to receptors on ____________ __ releasing neurons and decreased amount of ___________ __ are released to suppress pain

Substance P; Substance P