Chemical Senses - Smell

These flashcards cover concepts regarding the chemical senses, particularly focusing on how smell works, its importance, detection thresholds, identifying odors, the role of different brain structures, and the connection between smell and memories.

What is the difference between microsmatic and macrosmatic?

Microsomatic refers to having a weak sense of smell, while macrosomatic refers to having a keen sense of smell important for survival.

How many olfactory receptors do humans have?

Humans have about 350-400 different types of olfactory receptors.

What is the detection threshold in olfaction?

The detection threshold is the lowest concentration at which an odorant can be detected.

What method determines a person's detection threshold?

The Forced-Choice Method, where a subject identifies a trial with an odorant 75% of the time.

What is the significance of the Proust Effect?

It refers to the elicitation of memories through taste and olfaction, named after Marcel Proust.

What is an odor object?

An odor object is the source of an odor, such as coffee or roses.

How do we perceive groups of smells?

We perceive a mixture of many chemicals at once, rather than individually.

What role does the olfactory bulb play in smell?

The olfactory bulb receives signals directly from olfactory receptors and contains glomeruli for processing this information.

Why are odor objects difficult to describe?

There is a lack of specific language for odor quality, making it difficult to describe them universally.

What is the role of the amygdala in olfactory processing?

The amygdala is involved in emotional responding and processing olfactory signals.

What happens during the retronasal route?

Compounds from the mouth travel through the nasal pharynx to contribute to flavor perception.

How are memories associated with smells?

Olfactory cues can trigger autobiographical memories, especially from childhood.

What is anosmia?

Anosmia is the loss of the ability to smell due to injury or infection.

What occurs during oral capture?

Olfactory and taste sensations are perceived as being located in the mouth.

What influences our perception of flavor?

Expectations and prior experiences influence how we perceive flavors.

What is sensory-specific satiety?

It is the effect on odor perception associated with food eaten to satiety.

What are bimodal neurons?

Bimodal neurons respond to stimuli associated with more than one sense.

What is flavor?

Flavor is a combination of taste and olfaction, providing an overall impression of food.

What are chemotopic maps in olfactory processing?

Chemotopic maps represent the activation pattern in the olfactory system based on chemical properties.

What is the primary olfactory area?

The piriform cortex is the primary olfactory area that receives signals from the olfactory bulb.

How does the brain process different odors?

The brain creates a 'map' of the odorant's features through the firing patterns in the olfactory bulb.

What is the role of the hippocampus in olfactory memory?

The hippocampus is involved in storing and retrieving memories related to odors.

How does the olfactory mucosa contribute to smell?

The olfactory mucosa contains millions of olfactory receptor neurons that detect odor stimuli.

What is the function of glomeruli in the olfactory bulb?

Glomeruli collect information about small groups of similar odorants.

How does flavor perception occur in the cortex?

Flavor perception is created when taste and olfactory signals converge in the cortex.

What influences the reward value of food?

The orbitofrontal cortex determines the reward value, affecting food intake.

How can the sense of smell change in Alzheimer's disease?

Loss of smell can be an early sign, with abnormal olfactory functioning rising before clinical symptoms.

What does it mean for an odorant to have a recognition profile?

It indicates which olfactory receptor neurons are activated by the odorant, based on its chemical structure.

How can flavor be affected by what one expects?

Expectations can alter perception, where anticipated pleasantness can enhance the flavor experience.

What is isolated congenital anosmia?

A condition where a person is born without a sense of smell.

What are odor-evoked autobiographical memories (OEAMS)?

Memories about personal life events that are triggered by specific odors.

How does the olfactory system help differentiate between odors?

It relies on the activation patterns of olfactory receptors that respond differently to various odorants.