Olfaction Flashcards
What are organic molecules suspended in the air, that can be recognized by the olfactory system and produce a signal of smell
odorants
What is another way to say a signal of smell?
odor (e.g. cinnamaldehyde)
A recognizable mixture of odorants is called an ______________.
aroma (e.g. roses, coffee)
_________________ are suspended in the air, and are inhaled when we breathe.
Odorants
Odorants are inhaled in the nasal and oral cavities, where they find the _______________ and activate the olfactory system
olfactory mucosa
Orthonasal smell =
inhalation
Retronasal smell =
aromatic fine taste
The ____________ are narrow, curled bones that protrude into the nasal cavity.
nasal conchae, or turbinates,
What are nasal conchae (turbinates) responsible for?
- majority of airflow direction,
- humidification
- heating and filtering of inhaled air
What protect the sinuses from pressurized nasal airflow and the olfactory bulb.
nasal conchae, or turbinates
What is the name of the brain region that mediates olfaction.
olfactory bulb
The olfactory epithelium is a thin ___________________ found at the roof of the nasal cavity around 7 cm (~2.5 in) behind the nostrils
sensory epithelium
What is formed by olfactory receptor cells?
olfactory epithelium
What detect the presence of odorants at low concentrations such as 10 parts per trillion!
olfactory receptor cells
The _______________ of olfactory info occurs in the olfactory epithelium.
transduction
TRUE OR FALSE:
Olfactory receptor cells are neurons.
TRUE
What bind the receptor cilia of olfactory neurons to elicit a signal transduction cascade?
Odorants
When an odorant binds the neurons, they send signals trough their olfactory axons to synapse in the _____________.
olfactory bulb
Olfactory receptor cells are one of the few neurons with _______________________ ___________________.
continuous regenerative capacity (neurogenesis!)
What is the order of the mucous membrane (olfactory epithelium)?
TOP
* olfactory filum
* basal cell
* olfactory receptor cell
* supporting cells
* olfactory knob
* receptor cilia
BOTTOM
Axons of olfactory neurons reach the olfactory bulb through __________________ in the ___________ plate and synapse with bulbar second order neurons in regions known as ______________. These neurons’ projections are known as ____________________.
foramina
cribiform
glomeruli
olfactory stria
Olfactory neurons expressing the same type of olfactory receptor innervate a ______________________.
single glomerulus
TRUE OR FALSE:
Odorants are able to be coded by the pattern of activity in the olfactory bulb.
TRUE
The majority of second order neurons from the olfactory bulb project to the _______________________ without synapsing in the _______________.
primary olfactory cortex
thalamus
TRUE OR FALSE:
There are also neurons that directly project to limbic structures.
TRUE
As part of the ________________, the olfactory bulb has extensive connections to other regions in this system. This allows for coding of olfactory information.
limbic system
From the olfactory bulb, what is the fastest route to olfactory memories?
Olfactory bulb -> primary olfactory cortex -> entorhinal area
From the olfactory bulb, what is the fastest route to emotional and motivated responses to odors?
Olfactory bulb -> primary olfactory cortex -> septal areas
From the olfactory bulb, what are the fastest routes to attentional behavior and responses to odors?
1.) Olfactory bulb -> amygdaloid complex -> orbitofrontal cortex
2.) Olfactory bulb -> primary olfactory cortex -> thalamus medial dorsal nucleus -> orbitofrontal cortex
