Olfaction Flashcards

1
Q

anosmia

A

total loss of smell

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2
Q

What is the sense of smell called?

A

Olfaction

Olfaction is a critical sensory system involved in detecting airborne chemicals.

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3
Q

What are the two ways the sense of olfaction can be stimulated?

A
  • O_____- nasal: odours inhaled through the nose
  • R_____-nasal: occurs when odorants travel from the mouth to the olfactory receptors

O_____-nasal refers to the direct inhalation of scents, while R_____-nasal relates to the retro-nasal perception during eating.

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4
Q

What is the first step in the olfactory pathway?

A

Odor molecules enter the nasal cavity and dissolve in the mucus layer of the nasal epithelium

This step is crucial for the detection of smells.

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5
Q

What happens when an odorant binds to an olfactory receptor?

A

It triggers a biochemical reaction that generates an electrical signal in the receptor cell

This process is essential for transmitting olfactory information to the brain.

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6
Q

What is the role of the olfactory bulb?

A

Processes electrical signals and relays them to the glomeruli

The olfactory bulb is a key structure for organizing scent information.

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7
Q

Which brain areas receive processed olfactory signals?

A
  • Olfactory cortex
  • Amygdala
  • Hippocampus
  • Thalamus
  • Insula

These areas are involved in various aspects of smell processing, emotion, and memory.

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8
Q

What is the olfactory epithelium?

A

Part of the mucosa that lines the nasal cavity, responsible for detecting odours

The olfactory epithelium contains sensory receptors for smell.

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9
Q

How long is the lifespan of olfactory receptor cells?

A

1 month

These cells are continuously replaced in the nasal cavity.

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10
Q

What is the primary olfactory cortex called?

A

Piriform cortex (PC)

The PC plays a key role in processing olfactory information.

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11
Q

What is olfactory acuity?

A

A person’s ability to discriminate between odours

This ability varies across different types of smells.

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12
Q

What is short term adaptation in olfaction?

A

Decrease in responsiveness under conditions of constant stimulation

It leads to a rapid loss of odour intensity.

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13
Q

What is anosmia?

A

Total loss of smell

It is diagnosed when an individual deviates significantly from the population mean.

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14
Q

What is parosmia?

A

A change in normal perception of smell

It can cause good smells to be perceived as unpleasant.

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15
Q

What does the term ‘olfactory liking’ refer to?

A

Individual differences in the preference for certain smells

For example, some people find coriander unpleasant due to specific olfactory receptors.

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16
Q

What is the Proustian effect?

A

Odour memories evoke emotional, autobiographical memories

This phenomenon illustrates the strong link between smell and memory.

17
Q

What is the olfactory threshold?

A

Lowest concentration of a chemical in air that people can detect

This varies among individuals and substances.

18
Q

What does the term ‘population coding’ refer to in olfaction?

A

Odour detection is represented by the overall activity across a population of neurons

This suggests that multiple neurons work together to identify smells.

19
Q

What are pheromones thought to involve?

A

The vomeronasal organ (VNO)

located just above the roof of the mouth

In humans, the VNO is considered vestigial and likely has lost its functional role.

20
Q

True or False: Humans have a larger olfactory bulb compared to dogs.

A

False

Humans have a smaller olfactory bulb compared to many mammals.

21
Q

What is the role of the hippocampus in olfaction?

A

Helps in forming odour-associated memories

The hippocampus is crucial for memory processing related to smells.

22
Q

Fill in the blank: The _______ is a structure in the brain that links odour to emotion and memories.

A

Amygdala

The amygdala plays a significant role in emotional responses to smells.

23
Q

hyposmia

A

reduced sense of smell

24
Q

parosmia

A

unpleasant sense of smell - change in perception

25
Q

phantosmia

A

presence of smell when smell isn’t there

26
Q

specific anosmia

A

some people unable to detect families of similar smell compounds