CHEMICAL SENSES

Question 1

RECEPTOR TYPES: Bipolar cells embedded in the olfactory epithelium

Pathways to Connection:
Axons from the receptors synapse in the glomeruli of the olfactory bulbs. *

Axons from the olfactory bulbs form the olfactory tract and synapse in the olfactory cortex. *

The olfactory cortex sends information to the thalamus, limbic system, insula, and orbitofrontal cortex.

Answer 1

Olfaction

Question 2

RECEPTOR TYPES: Taste buds on the tongue and elsewhere in the mouth

PATHWAYS AND CONNECTION:
* Fibers serving the taste receptors join cranial nerves VII, IX, and X.

• These axons synapse in the gustatory nucleus of the medulla.
• Axons from the gustatory nucleus synapse in the ventral posterior medial (VPM) nucleus of the thalamus.
• VPM axons synapse in somatosensory cortex and in the orbitofrontal cortex.

Answer 2

Taste

Question 3

sense of smell.

Answer 3

Olfaction

Question 4

The layer in the nasal cavity containing olfactory receptors.

Answer 4

Olfactory Epithelium

Question 5

Structures found within the olfactory bulbs.

Answer 5

Glomeruli

Question 6

A fiber pathway connecting the olfactory bulbs to the olfactory cortex.

Answer 6

Olfactory Tract

Question 7

Cortex in the frontal lobe that responds to the sense of smell.

Answer 7

Olfactory Cortex

Question 8

One of the five basic taste groups, characteristic of tastes found in seaweed and other “meaty or savory” elements of Asian cuisine.

Answer 8

Umami

Question 9

Bumps on the tongue containing taste buds and taste receptors.

Answer 9

papillae

Question 10

Small fibers extending from taste receptors.

Answer 10

microvilli

Question 11

The nucleus of the thalamus that receives information regarding taste.

Answer 11

ventral posterior medial (VPM) nucleus of the thalamus

Question 12

Unlike many other types of neurons, olfactory receptor cells regularly die and are replaced in a cycle lasting approximately ____________

Answer 12

four to six weeks.

Question 13

In each glomerulus, approximately _______ olfactory receptor axons form synapses on about 100 olfactory neurons

Answer 13

25,000

Question 14

begins with the dissolving of molecules in the saliva of the mouth

Answer 14

Taste

Question 15

Four major categories of Taste

Answer 15

Sweet, Sour, Salty and Bitter

Question 16

Each bump on the surface of the tongue, known as a papilla, contains somewhere between _____ taste buds, which are too small to be
seen with the naked eye

Answer 16

1 and 100

Question 17

Most taste buds contain somewhere between ___________ taste receptor cells. The taste receptor cells are not technically considered to be neurons, although they do have the capability of forming synapses. Each taste receptor has a number of thin fibers known as microvilli that
extend into the saliva

Answer 17

50 and 150

Question 18

Taste Pathways

Answer 18

Taste Receptor Activation > Nerve Transmission > Central Processing

Question 19

Taste sensations begin when taste
buds on the tongue and other oral structures are activated by
various chemicals in food and drink. Taste receptors detect
sweet, sour, salty, bitter, and umami tastes.

Answer 19

Taste Receptor Activation

Question 20

Sensory nerves, primarily the facial (VII)
and glossopharyngeal (IX) cranial nerves, transmit taste signals
from the taste buds to the brainstem, where they synapse.

Answer 20

Nerve Transmission

Question 21

After synapsing in the brainstem, taste
signals travel to the thalamus and then to the gustatory cortex
in the brain’s insula and frontal operculum, where they are
processed and perceived as specific taste qualities.

Answer 21

Central Processing