Chemical senses Flashcards Preview

Foundations of Neuroscience > Chemical senses > Flashcards

Flashcards in Chemical senses Deck (24):
1

What are the functions of chemical senses?

Finding food
Finding a mate
Avoiding dangerous substances
Homeostasis

2

What are the receptors of chemical senses?

Chemoreceptors

3

What are the human chemical senses?

Taste (gustation)
Smell (olfaction)

4

What are the 5 basic tastes?

Salt
Sour
Sweet
Bitter
Umami

5

Where are the taste cells?

Tongue
Palate
Pharynx

6

What is the structural organisation of taste cells?

Papilla
Taste buds
Pore
Basal cells
Taste cells

7

What is the lifespan of taste receptor cells?

2 weeks

8

What are the stages from stimulus to action potential in a taste cell?

Chemical behinds
Receptor potential
Depolarisation
Voltage gated Ca2+
Calcium entry
Neurotransmitter released
Excites sensory neurone
Action potential

9

How is salt detected?

Sodium entry via non-gated channels
Results in depolarisation

10

How are sour tastes detected?

H+ entry via TRP
Blocks the K+ channel
Results in depolarisation

11

How are sweet, umami, bitter tastes detected ?

G protein coupled receptors
T1R and T2R families

12

Which nerves transmit taste?

VII
IX
X

13

Where does the signal go after the cranial nerves?

To the gustatory nucleus
Then the gustatory cortex

14

What is ageusia?

Inability to taste

15

What is neural coding of taste?

Comparing all pathways

16

What are the secondary pathways of taste?

Swallowing and salivation

17

What is more sensitive taste or smell?

Smell

18

What is the combination of taste and smell?

Flavour

19

Where are smell receptors?

Olfactory epithelium

20

Describe olfactory cells?

Olfactory cells are neurones
Replaced every 4-8 weeks
Each cell is one type of receptor molecule
Each receptor molecule binds a range of odorants

21

What is population coding?

Co-ordinated firing of multiple neurones

22

How are action potentials triggered in olfactory cells?

Odorant binds to receptor
G protein mediated events
Intracellular cascade
Na+/Ca2+ channels open
Depolarisation
Receptor potential
Action potential

23

Which cranial nerve carries olfactory signals?

I

24

What is the olfactory pathway?

Olfactory neurons
Olfactory bulb
Olfactory cortex
Recognition/association in the orbitofrontal cortex