Nose and throat

Question 1

What is another name for the windpipe?

Answer 1

The trachea.

Question 2

What is the name for the voice box?

Answer 2

The larynx.

Question 3

What is the hard palate?

Answer 3

The front part of the roof of the mouth.

Question 4

What is the soft palate?

Answer 4

The back part of the roof of the mouth.

Question 5

How is sound produced?

Answer 5

There is a flow of air past the vocal cords that causes vibration, causing sounds.

Question 6

What are vocal cords comprised of?

Answer 6

1. Epithelium
2. mucous connective tissue
3. muscle.

Question 7

What does the supralaryngeal do?

Answer 7

Modify harmonics.

Question 8

How are different sounds produced?

Answer 8

1. Harmonics modified by supralaryngeal structures
2. Structures in the vocal tract form a series of valves that change the shape of the tract to produce different sounds.
3. The moveable articulators (lips, tongue and velum) act as valves to close or constrict the tube to produce speech sounds- their position modulates sound
   3.

Question 9

What are the functions of the nose?

Answer 9

1. Breathing
2. air conditioning (temperature and humidity)
3. protection (particulate and bacterial)
4. airway patency
5. vocal resonance
6. olfaction.

Question 10

What cells is the nasal lining composed of?

Answer 10

1. Stem cells
2. goblet cells
3. ciliated columnar epithelial cells
4. cilia
5. a mucus layer

Question 11

What is olfaction?

Answer 11

The sense of smell.

Question 12

Where is olfactory epithelium found?

Answer 12

1. In the roof of the nose.

2. It contains olfactory receptors.

Question 13

What happens to odorants that we inhale?
olfactory epithelium in roof of nose
odorants inhaled – dissolve in mucous
olfactory receptor cells excited

Answer 13

1. Odorants are inhaled

2. They are dissolved in the mucus that covers the epithelium.

Question 14

What happens to odorants after they are inhaled?
OR cells release glutamate from optic nerve terminals
mitral cells excited
mitral cells send action potentials to olfactory cortex

Answer 14

1. They bind to olfactory receptors and become excited.
2. Glutamate is released from optic nerve terminals
3. mitral cells are excited that then send action potentials to the olfactory cortex.

Question 15

What happens after action potentials are sent to the olfactory cortex after odorants are inhaled?

Answer 15

1. mitral cells project to olfactory (piriform) cortex and other areas
2. Specific neurone sets in the cortex respond to specific odors
3. Information is passed to other areas for association and integration.
4. e.g. visual cortex, amygdala and entorhinal cortex/hippocampus

Question 16

What cortex is involved in smell and sight?

Answer 16

The visual cortex.

Question 17

What cortex is involved in smell and fear?

Answer 17

Amygdala.

Question 18

What cortex is involved in smell and memory?

Answer 18

The entorhinal cortex/the hippocampus.

Question 19

What is glomeruli?

Answer 19

Mitral cells.

Question 20

How are odorants specific?

Answer 20

They have specific chemical groups to distinguish it so activates a different receptor type.

Question 21

How can we smell different things?

Answer 21

1. large numbers of different odorant receptors (>300)
2. each cell expresses only a few
3. olfactory receptor cells respond preferentially
4. different types of cell have different profiles of activity
5. but olfactory receptor cells converge onto specific mitral cells (glomeruli)
6. so activation patterns of glomeruli are important

Question 22

How does taste work?

Answer 22

1. Taste cells in the tongue respond to chemicals in food.

2. This information is relayed to brain gustatory centres and the body prepares for digestion.

Question 23

Where are taste cells located?

Answer 23

1. In papilla over the full surface of tongues.

Question 24

What benefit can taste provide?

Answer 24

Defense against harmful substances.

Question 25

How many taste buds are in the tongue and how many taste receptor cells (trc)

Answer 25

1. 2000-5000 taste buds

2. 50-100 trc

Question 26

What are the 5 basic tastes?

Answer 26

Bitter, sour, sweet, salty, umami.

Question 27

How does the distribution of taste receptor cells vary on the tongue?

Answer 27

There is preferential but overlapping locations on the tongue.

Question 28

Describe sensory transduction in taste cells?

Answer 28

1. tastants activate GPCRs or ion channels
2. intracellular pathways increase calcium levels
3. transmitters released by exocytosis or through ion channels
4. Neurotransmitters (ATP, serotonin) activate gustatory neurones
5. information sent to brain

Question 29

How can the interpretation of different tastes within one substance occur?

Answer 29

1. Taste cells can respond to more than one tastant
2. the strength of response differs for different tastes.
3. The output to the brain varies accordingly
4. allows for interpretation of different tastes within a single substance

Question 30

When the vocal cord is closed what else is closed

Answer 30

1. The glottis is closed

2. The glottis is open when the vocal cord is open

Question 31

What are tastants

Answer 31

1. most tastants non-volatile and soluble in saliva

2. 4 different types, only 3 gustatory (not filiform)

Question 32

How do taste buds work

Answer 32

1. modified epithelial cells
2. gustatory hairs or cilia sense tastants in taste pore
3. trc release transmitters to activate cranial nerves
4. basal cells are trc progenitors
5. taste cells respond preferentially to tastants

Question 33

Describe taste pathways to the brain

Answer 33

1. neurones project through cranial nerves
2. relays in brainstem and thalamus
3. connections to amygdala and other areas mediate emotional memory and aversion