A&P 2 Flashcards: Taste and Smell

What are the 3 main cell types in the olfactory epithelium?

1. Olfactory receptors

2. Supporting cells

3. Basal cells

What is the function of olfactory receptor neurons?

Detect odorant molecules and convert them into nerve signals

What structure on olfactory receptor neurons bind odorants?

Cilia that extend into the mucus layer

Why are basal cells important?

They are cells that replace damaged olfactory receptor neurons

What produces the mucus covering the olfactory epithelium?

Olfactory glands (Bowman’s glands)

Which cranial nerve carries signals from the olfactory epithelium to the brain?

Cranial nerve 1

What happens after an odorant binds to a receptor on olfactory cilia?

A G-Protein pathway causes depolarization of the olfactory neuron

Where do olfactory receptor neuron axons go after leaving the epithelium?

Through the cribriform plate to the olfactory bulb

Why does olfaction bypass the thalamus initially?

It has direct connection to the limbic system, links smell to emotion and memory

What 2nd messenger is used in olfactory signal transduction?

cAMP (via a g-protein coupled receptor)

Low threshold

Only a few molecules needed to detect smell

Outline the basic olfactory pathway

1. Olfactory nerves.

2. Olfactory bulbs.

3. Olfactory tracts.

What is gestation?

Sense of taste

What are the 3 type of papillae that contain taste buds?

Vallate, Fungiform, foliate

Does filiform papillae contain taste buds?

No

What cells make up a taste bud?

1. Gustatory cells

2. Supporting cells

3. Basal cells

What are the 5 taste modalities?

Sweet, salty, sour, bitter, umami.

Salty foods use what type of ion

NA+ (sodium)

Sour taste use what type of ion?

H+ ions enter H+ channels (Hydrogen)

Which taste modalities use g-protein mediated receptors?

Bitter, sweet and umami

Which cranial nerves carries taste from the anterior 2/3rd of the tounge?

CN VII(Facial nerve)

Which cranial nerve carries taste from the posterior 1/3rd of the tounge?

CN IX (glossoparyngeal nerve)

Which cranial nerve carries taste from the epiglottis?

CN X (vagus nerve)

Outline basic gustatory pathway.

1. Taste receptor

2. 2. Cranial nerves (VII, IX, X)

3. Brainstem

4. Thalamus

5. Gustatory cortex in the cerebral cortex

What is vallate papillae

Large v-shaped row of taste buds in the back of the mouth