Ch 15: Olfaction
Olfactory bulb
a part of the brain just behind the nose that is the first place in the brain where olfactory information is processed
Orbitofrontal cortex
a part of the prefrontal cortex that appears to be critical in the emotional experience of odors and integrating olfaction and taste perception, among other functions
cribriform plate
a perforated section of skull bone that operates the nose from the brain; axons from olfactory receptor neurons pass through to allow olfactory information to enter regions in the brain
tip-of-the-nose phenomenon
a phenomenon that occurs when a person is familiar with an odor but cannot recall its name, despite feeling as if he or she can
Posterior piriform cortex
a structure located in the back portion of the piriform cortex that is associated with an odor's quality, regardless of its chemical composition
Anterior piriform cortex
a structure located in the front portion of the piriform cortex that is associated with representing the chemical structures of odorants
Piriform cortex
an area in the anterior region of the temporal lobe that receives input from the olfactory bulb and is involved in olfactory processing; often considered the primary olfactory cortex
Entorhinal cortex
an area in the medial temporal lobe, associated with a number of memory functions
amygdala
an area of the brain in the limbic system, associated with the experience of emotion, particularly fear
olfactory receptor neurons
receptor cells located in the olfactory epithelium that detect specific chemicals in the air and transduce them into a neural signal
anosmia
the inability to smell, usually caused by cribriform plate damage
Trigeminal nerve
a nerve that is associated with the feel of odorants: cranial nerve V
mitral cells
___ ___ are more likely to inhibit the olfactory process
verbal labeling, Stevenson
___ ___ can cause olfactory illusions and can affect whether the participant perceives a positive or negative smell and was demonstrated by _____ who found that the first label of a smell influenced the perception more
color
___ was found to influence smell even when there was no smell present in liquids
olfactory epithelium
a mucous membrane inside each nostril of the nose that contains the receptor cells for the olfactory system
turbinates
bony knots of tissue that serve to disperse air within the nasal cavity
basal cells
cells that create olfactory receptor neurons
supporting cells
cells that provide metabolic supplies to the olfactory receptor neurons
different
different odorants require ___ concentrations to be detected
discrimination
distinguishing between two stimuli
imagery
experiencing a sensory experience that is previously known but not presently experienced is known as olfactory ___
olfactory rivalry
in ___ ___ one odorant is presented to one nostril, and a different odor presented to the other. People reported smelling one and then the other but not both at the same time
Lawless
in ___'s illusion a chemical smelled woody when surrounded by citrus and citrusy when surrounded by woody
inactive
in humans we only use 350 of 1,000 genes coding for sense of smell, most are ____
odorants
molecules our olfactory system responds to when we detect them in the air
mitral cells
neurons that start in the glomeruli of the olfactory bulb and project to other areas of the brain; respond to different odorants than do tufted cells
Tufted cells
neurons that start in the glomeruli of the olfactory bulb and project to other areas of the brain; they respond to different odorants than do mitral cells
parts per million (ppm)
odor is measured in ___ ___ ___
28
olfactory receptor neurons are completely regenerated every ___ days
cilia
olfactory receptor neurons have ___ extending into the mucus covering of the olfactory epithelium where a chemical triggers the cilia causing a neural signal to begin
memory, emotion
smell is associated with ___ and ____
microsomatic
species (such as humans) that are more dependent on vision and audition are called ___
macrosomatic
species that depend heavily on smell are called ____
glomeruli
spherical structures within the olfactory bulb where the olfactory tract forms synapses with mitral cells and tufted cells
olfactory nerve
the axons of the olfactory receptor neurons that leave the nose and enter the olfactory bulb. Cranial nerve I
odorant map
the cells in the glomeruli form an ___ ___ that organizes chemicals with similar structures near one another
olfactory cleft
the channel at the back of the nasal cavity that funnels air up towards the olfactory epithelium
olfactory tract
the pathway leading from the olfactory bulb to other regions of the brain
odors
the perceptual experience airborne chemical stimuli
olfaction
the sense of smell
gustation
the sense of taste
nasal septum
the wall of cartilage that operates the nostrils
20 million
there are approximately ___ ____ olfactory receptor neurons in the human nose, more than any other sense
language
there seems to be a disconnect between olfaction and ___