Olfaction

Question 1

How do we sent smell?

How many different odors can we sense?

Answer 1

We can smell about 2000-4000 different odors

• by sensing different molecules, direct molecular mechanism is largerly unknown

Question 2

What are the types of olfactory cells in the olfactory epithelium?

What is their respective function?

Answer 2

Three types

1. bipolar olfactory neurons
   
   • receptor cells to sense smells and go to olfactory bulb
2. sustentacular cells
   
   • like glia cells (hold everything together)
3. Basal cells
   
   • recovery theoretically possible

Overall: progressive loss with age

Question 3

Explain the route of olfactory neurons

Answer 3

1. Bipolar Olfactory receptive cells
   
   • go through cirbiform plate
   • synapse in glumberulus in olfactory bulb
2. Second order olfactory neurons form the olfactory tract
3. Olfactory tract split into
   
   • lateral olfactory stria (going to piriform cortex)
   • medial olfactory stria (going to orbitofrontal cortex)
4. • Connection to brain stem promotes autonomic response (supermarket bakery)

Question 4

How do you call the loos of ability to smell?

Answer 4

Anosmia

Question 5

What is a prodromal aura?

Answer 5

Smell as prediction e.g. of a epilptic seizure:

• anatomical relation to temporal area (where many seizures are initiated)
• evoke smell before seizure

Question 6

Explain the relationship of anosmia and neurodegenerative disorders

Answer 6

Often, a loss of smell is associated with a neurodegenerative disorder

Answer 7

1. 1st order: olfactory receptor cells synapse onty glumerulos of
2. nd order olfactory neuron, cell bodies situated in the olfactory bulb and form the olfactory tract