Chemosensation

Question 1

Ageusia:

Answer 1

loss of taste

Question 2

Anosmia

Answer 2

loss of smell

Question 3

test smell

Answer 3

scratch and sniff test

Question 4

taste test

Answer 4

Patients react to different chemical concentrations in taste testing; this may involve a simple “sip, spit, and rinse” test, or chemicals may be applied directly to specific areas of the tongue.

Question 5

Simple chemosensation test

Answer 5

In clinic, 2/3 of people will complain of loss of taste.

However, once you actually check for loss of taste, instead, 90% have actually lost or reduced their sense of smell.

Question 6

Smell: Receptor cell =

Answer 6

ciliated bipolar neuron innervated by CN I w/ olfactory bulb as primary sensory nucleus.

Question 7

Taste: Receptor cell =

Answer 7

1. modified epithelial cell that synapses onto nerve fiber from cranial ganaglion cell to CN VII, IX, X.
2. The primary CNS nucleus is the NST.

Question 8

Chemisthesis: Receptor cell:

Answer 8

1. free nerve ending of cranial ganglion cell innervated by CNV.
2. Detection of irritant chemicals by trigeminal nerve endings.
3. Primary sensory nucleus is Spinal Trigeminal Nucleus.

Question 9

Ortho-nasal =

Answer 9

actually through your nostrils.

Question 10

Retro-nasal =

Answer 10

through your mouth traveling through the concha to get to the olfactory epithelium.

Question 11

CN 3 exits midbrain at

Answer 11

interpeducular cistern

Question 12

CN 4 exits midbrain

Answer 12

dorsally, just below inferior colliculus (note it originates in contralateral midbrain and crosses before it exits the brainstem)

Question 13

CN 5 enters/exits

Answer 13

the lateral pons. fibers traverse middle cerebellar peduncle

Question 14

CN 6 exits

Answer 14

medially at the ponto-medullary junction

Question 15

CN 7/8 exit and enter respectively

Answer 15

at cerebello-pontine angle

Question 16

CN 9/10 exit

Answer 16

the lateral medulla (between olive and inferior cerebellar peduncle)

Question 17

CN 11 originates

Answer 17

From c1-c5 segments of spinal cord

Question 18

CN 11 exits

Answer 18

the spinal cord laterally–in between the dorsal and ventral rootlets.

Question 19

CN 12 exits

Answer 19

medulla between olive and pyramid.

Question 20

Secondary gustatory cortex is located

Answer 20

in the orbitofrtonal surface

areas.

Question 21

Secondary gustatory cortex receives projections from

Answer 21

1. the primary gustatory area located on the interior insula

2. olfactory insula

Question 22

Orbitofrontal cortex:

Answer 22

where integration of taste and smell leads to perception of FLAVOR!!!