Special Sensory Pathways (Quiz 3)

Question 1

What are the 4 types of receptors that detect chemicals and project this info to the CNS?

Answer 1

1) visceral chemoreceptors (pH, glucose, oxygen, hormones)
2) gustatory receptors (taste)
3) olfactory receptors (smell)
4) general chemical sensations (peppers, stings, cooling) + general tactile for gustation

Question 2

Where does the olfactory system begin?

Answer 2

at the olfactory epithelium (superior surface of the nasal cavity)

Question 3

What CN sensory endings is located in the olfactory epithelium?

Answer 3

CN V (noxious)

Question 4

What nerve classification do olfactory receptors have?

Answer 4

bipolar neurons

Question 5

What axonal classification do olfactory neurons have?

Answer 5

C fibers (these are the thinnest, and are unmyelinated axons)

Question 6

The olfactory nerve (CN 1) axons bundle and pass through cribriform plate to form…

Answer 6

olfactory bulb

Question 7

How many different types of receptors and genes are there for olfaction?

Answer 7

300 different receptors, 1000 different genes

she may ask this bc she kept repeating it in class

Question 8

Which cell is found within the olfactory bulb?

Answer 8

mitral/tufted cells

Question 9

What is the stem cell called that is found in olfactory epithelium?

Answer 9

basal cell

Question 10

Can you smell anything in super dry environments?

Answer 10

no the receptors are only capable of binding odors in moist environments, so anything super dry will result in no smell.

Question 11

define odor

Answer 11

anything that binds to the cilia in the nose

Question 12

What is the olfactory pathway?

Answer 12

1) olfactory receptor cells (dendrites)
2) olfactory nerves
3) olfactory bulb (mitral and tufted cells/neurons)
4) olfactory tract
5) olfactory striae (divides into medial and lateral stria)
6) olfactory cortex
7) output targets of the olfactory cortex

Question 13

What is the ONLY sensory pathway that foes not use the thalamus?

Answer 13

olfactory pathway

Question 14

The olfactory bulb is an outgrowth of the….

Answer 14

telencephalon

Question 15

The olfactory bulb sends axons in what directions?

Answer 15

caudally and laterally

Question 16

The lateral olfactory tract curves up into the _____________ lobe where the fibers disperse and terminate

Answer 16

temporal

Question 17

Where does the olfactory pathway terminate?

Answer 17

primary olfactory cortex and amygdala

Question 18

Different odorants activate different sets of _____________ in patterns

Answer 18

glomeruli

(there odors are compared to known saved patterns of smell (memory))

Question 19

What are the 2 olfactory cortexes called?

Answer 19

1) piriform cortex
2) entorhinal cortex

Question 20

What is known as the emotional system?

Answer 20

limbic system

Question 21

What is known as the memory area?

Answer 21

hippocampus

Question 22

The olfactory cortex is in which lobe?

Answer 22

temporal lobe

Question 23

T/F: gustation involves olfaction and vision

Answer 23

true

Question 24

Which CN sensory input is involved with gustation?

Answer 24

CN V

Question 25

Taste buds (neurons) are organized within and on ___________

Answer 25

papillae

Question 26

What CNs innervate taste buds?

Answer 26

facial, glossopharyngeal, and vagus n.

Question 27

Which nucleus do facial, glossopharyngeal, and vagus n. project to?

Answer 27

solitary nucleus

Question 28

Which CN transmits texture, temp, and pain in regards to gustation?

Answer 28

CN V

Question 29

Where are circumvallate (v shaped) papillae located?

Answer 29

back of the tongue (posterior 2/3 of tongue)

Question 30

Where are fungiform papillae located?

Answer 30

body of tongue (middle, anterior 2/3 of tongue)

Question 31

Where are filiform (hairlike) papillae located?

Answer 31

tip of tongue

Question 32

Which papillae does not transmit taste but does transmit texture and movement?

Answer 32

filiform papillae

Question 33

How many taste buds does each fungiform papilla have?

Answer 33

3-5 taste buds

Question 34

How many taste buds does each circumvallate papilla have?

Answer 34

250 taste buds

Question 35

Receptors within taste buds that perceive sweetness is located at tip of tongue. What CN is involved here?

Answer 35

facial n.

Question 36

Receptors within taste buds that perceive bitterness is located on the back of tongue. What CN is involved here?

Answer 36

glossopharyngeal n.

Question 37

Receptors within taste buds that perceive osmolarity (water) is located in the back of the tongue. What CN is involved here?

Answer 37

vagus n.

Question 38

Taste cells have epithelial origin but are very much like neurons. What are some of their functions?

Answer 38

-produce receptor potentials
-respond to chemicals (ingested stimuli)
-make typical synapses on cranial nerves
-some produce action potentials
-BUT they only 8-14 days then replaced (not neural)

Question 39

Which taste category is involved with the AA glutamate

Answer 39

umami (earthy, rich, aged taste)

Question 40

How many taste buds are on the average tongue?

Answer 40

5000

Question 41

For the olfactory system, from the nucleus of the solitary tract in the rostral medulla (input from CN VII, IX, and X). Axons project up the solitary tract through the pons joining the ______________________ and synapses in the thalamus

Answer 41

central tegmental tract

Question 42

Chemosensory info from the oral cavity is perceived as ___________

Answer 42

flavor

Question 43

The input to the solitary nucleus forms 2nd order neurons that do 2 things. What are they?

Answer 43

1) reflex activities (salvation, swallowing (coughing))
2) project- thalamic- cortex. Uncrossed, ipsilateral central tegmental tract

(other projections are to the amygdala, frontal lobe, limbic system, and hypothalamus