taste and olfaction Flashcards
what cranial nerve is near the epiglottis?
X
what cranial nerve is near the circumvallate papillae?
IX
what cranial nerve is near the fungiform papillae?
VII
what cranial nerve affects the posterior 1/3 of the tongue?
IXwh
what cranial nerve affects the anterior 2/3 of the tongue?
VII
what are the 5 tastes?
Sweet
Salty
Sour
Bitter
Umami
what do taste molecules dissolve in?
saliva
what kind of receptors are taste buds?
chemoreceptors
what chemical signals happen with the salt taste?
Na influx
what chemical signals happen with the sour taste?
H blocks K channel
what chemical signals happen with the sweet taste?
glucose activating Gprotein, the cAMP then phosphorylation and blockage of K
what chemical signals happen with the bitter taste?
G protein gustducin, inhibit phosphodiesterase and increase cAMP
what chemical signals happen with the umami taset?
triggered by amino acids
what is the taste pathway?
At the tongue = in the medulla = in the pons = in the ventral-posterior medial thalamus, hypothalamus and amygdala = insular and orbital cortex
what 3 types of smells can be used for medical detection?
Infection after surgery = wine
Diabetic coma = apple breath
Arsenic poisoning = garlic body
where is odor first detected?
cilia of olfactory receptor. if signal is strong enough it will generate action potential.
hwo does odor adaptation occur?
The Ca2 signal controls both excitation and adaptation
Ca2 -CAM binds to the CNG channel, reducing its affinity for CAMP
The extrusion of Ca2 through the activation of Na/Ca2 exchange proteins
what did Linda Buck and Richard Axel discover?
odorant receptors and organization of olfactory system
what type of neuron do olfactory bulbs contain?
first order
are seperate components of an odor seperated into different glomeruli?
yes
what cells do the neurons synapse on?
mitral cells
what do mitral cells do?
refine the small sense and relays it to the brain for further processing
what is the subcortical route?
regions of limbic system - medial sides of temporal lobe (primary olfactory cortex)
what is the thalamo-cortical route?
for conscious perception of smell and fine discrimination of smell
