Olfactory system

ajv09c's version from 2015-04-30 04:47

Section 1

Question Answer
five special sensesolfaction, gustation, vision, equilibrium, hearing
olfactory organs providesense of smell
olfactory organs located in nasal cavity on either side of nasal septum
olfactory organs made up oftwo layers; olfactory epithelium and lamina propria
olfactory epithelium containsolfactory receptor cells, supporting cells, basal (stem) cells
basal (stem) cells regenerate olfactory receptor cells
lamina propria containsareolar connective tissue, blood vessels, nerves, olfactory glands
olfactory glands producemucus

Section 2

Question Answer
olfactory glands secretions coat surfaces of olfactory organs
olfactory receptorshighly modified neurons; involves detecting dissolved chemicals as they interact with odorant-binding proteins
odorant-binding proteins locatedon the cell membrane of olfactory receptor cell
olfactory pathways areaxons leaving olfactory epithelium, then collected into 20 or more bundles
axons penetratethe cribriform plate of ethmoid
after the cribriform axons reachthe olfactory bulbs of cerebrum where first synapse occurs
axons leaving the olfactory bulb travelalong olfactory tract to reach olfactory cortex, hypothalamus, and portions of limbic system
olfactory pathway info reaches information centers without first synapsing in thalamus

Section 3

Question Answer
olfactory discriminationcan distinguish thousands of chemical stimuli; cns interprets smells by the pattern of receptor activity
olfactory receptor populationconsiderable turnover- receptor cells replaced by basal cells
number of olfactory receptors (and sense of smell) declines withage
odorants aredissolved chemicals that stimulate olfactory receptors; small organic molecules
strongest smells are associated withmolecules of either high water or high lipid solubilities
smallest number of odorant molecules that activate an olfactory receptorfour
binding of odorant to its receptor protein leadsto the activation of adenylyl cyclades, the enzyme that converts atp to cyclic amp
the camp openssodium ion channels in the plasma membrane; leads to depolarization

Section 4

Question Answer
gustation providesinformation about the foods and liquids consumed
gustatory receptors akataste receptors
taste receptors are distributed on tongue and portions of pharynx and larynx
taste receptors are clustered intotaste buds