Sensation and Perception - Chapter 15

Ageusia

loss of the ability to taste

Amygdala

an area of the brain in the limbic system, associated with the experience of emotion, particularly fear

Anosmia (smell blindness)

the inability to smell, usually caused by cribriform plate damage

Anterior insular cortex (insula)

a part of the frontal lobe that serves as the primary taste cortex

Anterior piriform cortex

a structure located in the front portion of the piriform cortex that is associated with representing the chemical structures of odorants

Basal cells

cells that create olfactory receptor neurons

Circumvallate papillae

found along the very back of the tongue in a virtual row; they respond to all five basic tastes

Cribriform plate

a perforated section of skull bone that separates the nose from the brain; axons from olfactory receptor neurons pass through to allow olfactory information to enter regions in the brain

Entorhinal cortex

an area in the medial temporal lobe, associated with a number of memory functions

Filiform papillae

found all over the tongue; they contain somatosensory receptors rather than taste buds, so that they feel food rather than taste it

Flavor

the combined sensory experience of a food, which combines its taste, its odor, its effect on the trigeminal nerve, and even visual experience

Foliate papillae

found along the side of the tongue; they respond to all five basic tastes

Fungiform papillae

located mostly along the edges and top of the tongue; they respond to all five basic tastes

Glomeruli

spherical structures within the olfactory bulb where the olfactory tract forms synapses with mitral cells and tufted cells

Gustation

the sense of taste

Macrosmatic

species that are heavily dependent on their olfactory system

Microsmatic

species that are less dependent on their olfactory system

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

Nasal septum

the wall of cartilage that separates the nostrils

Nontasters

people who cannot detect bitter compounds except at very high concentrations

Odorants

molecules our olfactory system responds to when we detect them in the air

Odors

the perceptual experience of odorants, which are airborne chemical stimuli

Olfaction

the sense of smell

Olfactory bulb

a part of the brain just behind the nose; it is the first place in the brain where olfactory information is processed

Olfactory cleft

the channel at the back of the nasal cavity that funnels air up toward the olfactory epithelium

Olfactory epithelium

a mucous membrane inside each nostril of the nose that contains the receptor cells for the olfactory system

Olfactory nerve (first cranial nerve)

the axons of the olfactory receptor neurons that leave the nose and enter the olfactory bulb

Olfactory receptor neurons

receptor cells located in the olfactory epithelium that detect specific chemicals in the air and transduce them into a neural signal

Olfactory tract

the pathway leading from the olfactory bulb to other regions of the brain

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

Papillae

small structures that contain the taste buds

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

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

Presynaptic cells

taste receptor cells that transduce salty and sour tastes

Receptor cells

taste receptor cells that transduce sweet tastes, umami tastes, and bitter tastes

Supertasters

people who are extremely sensitive to bitter tastes; they usually do not like foods with many bitter compounds

Supporting cells

cells that provide metabolic supplies to the olfactory receptor neurons

Tastants

molecules recognized by taste receptors that induce responses in taste receptors on the tongue

Taste

the perception of the transduction of tastants along the surface of the tongue

Taste buds

small structures located along the surface of the tongue or mouth that contain the receptor cells

Taste receptor cells

cells within the taste buds that transduce tastants into a neural signal

Tasters

people who can detect bitter compounds

Tip of the nose phenomenon

a phenomenon that occurs when we are familiar with an odor but cannot recall its name, despite feeling as if we can

Trigeminal nerve

a nerve that is associated with the feel of odorants; also known as the fifth cranial nerve

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

Turbinates

bony knots of tissue that serve to disperse air within the nasal cavity