DSA 1: Neuroanatomy of Taste and Olfaction

Question 1

What type of receptors are odorant receptors?

Answer 1

GPCRs - ligand binding

Question 2

What are the olfactory fila?

Answer 2

Axons from the olfactory receptor neuron passing through the lamina propria and cribiform plate to the olfactory bulb

Question 3

What is the specificity of the olfactory receptor neurons?

Answer 3

Only express one type of odorant receptor that is processed in the olfactory bulb in the matching zone (individual glomeruli are thought to process different types of odors)

Question 4

What is the first structure contacted by olfactory receptor neurons after passing through the cribiform plate?

Answer 4

Olfactory glomerulus

Question 5

What are the layers of the olfactory bulb from superficial to deep?

Answer 5

1. Olfactory nerve layer
2. Glomerular layer
3. External plexiform layer
4. Mitral cell layer
5. Granule cell layer

Question 6

What cells do the olfactory receptor neurons synapse with in the glomerular layer?

Answer 6

Mitral and tufted cells

Question 7

What cell layer contains the cell bodies of tufted cells?

Answer 7

External plexiform layer

Question 8

How do granule cells moderate olfactory bulb activity?

Answer 8

Inhibitory feedback loop, release GABA into synapses w/ mitral and tufted cells

Question 9

What is the hallmark of the olfactory bulb?

Answer 9

Projects directly to the cortex, skips the thalamus

Question 10

What structure do the axons of the lateral olfactory tract contact to communicate with the contralateral olfactory tract?

Answer 10

Anterior olfactory nucleus

Question 11

What embryological structure contains the olfactory cortex?

Answer 11

Telencephalon

Question 12

What are the areas of the olfactory cortex?

Answer 12

Anterior olfactory nucleus

Olfactory tubercle

Piriform cortex

Anterior cortical amygdaloid nucleus

Periamygdaloid cortex

Lateral entorhinal cortex

Question 13

What is the role of the orbitofrontal cortex?

Answer 13

Integrates olfactory with taste to produce flavors

Question 14

What part of the thalamus receives olfactory information from the cortex?

Answer 14

Dorsomedial nucleus of the thalamus

Question 15

What structures does the lateral hypothalamus receive olfactory input from? What behaviors does this influence?

Answer 15

Piriform cortex and anterior olfactory nucleus

Feeding behavior

Question 16

What structure sends olfactory information to the hippocampus?

Answer 16

Entorhinal cortex

Question 17

What does the Chorda Tympani innervate in the peripheral taste pathway?

Answer 17

CN VII innervates fungiform papillae on anterior 2/3 of tongue and anterior foliate papillae

Question 18

What is the innervation to the taste buds on the soft palate?

Answer 18

Greater superficial petrosal N.

Question 19

Where are the cell bodies for CN VII for taste?

Answer 19

Geniculate ganglion

Question 20

What is the innervation to the taste buds in the vallate papillae and posterior foliate papillae?

Answer 20

Lingual-tonsillar branch of CN IX

Question 21

What is the innervation to the taste buds of the epiglottis and esophagus?

Answer 21

Superior laryngeal N. of Vagus N.

Question 22

Where are the cell bodies for the taste fibers of CN IX and X?

Answer 22

Inferior ganglia (Petrosal and nodose)

Question 23

Where do the fibers of the peripheral taste pathways terminate?

Answer 23

Gustatory nucleus (modulate taste and swallowing)

General visceral afferents

Question 24

What side does the central taste pathway travel on?

Answer 24

Ipsilateral side

Question 25

What CN has been lesioned if pt has paralysis in ipsilateral facial muscles, as well as lost of taste perception to anterior 2/3 of tongue?

Answer 25

CN VII

Question 26

If there is damage distal to the geniculate ganglion, what can result?

Answer 26

Ipsilateral facial paralysis

May or may not have taste loss

Question 27

What is ageusia?

Answer 27

Completely loss of taste

Question 28

Distortion in perception of a taste due to drugs or medications is called ____.

Answer 28

Parageusia/dysgeusia