Perception: The Chemical Senses

Vocabulary flashcards covering key terms and concepts from the lecture on perception, specifically focusing on olfaction and gustation.

Olfaction

The sense of smell, the perception of odorants by olfactory receptor neurons.

Odor

The perceptual experience created by an odorant.

Olfaction

The sense of smell, the perception of odorants by olfactory receptor neurons.

Odor

The perceptual experience created by an odorant.

Odorants

Volatile molecules that trigger responses by olfactory receptor neurons.

Orthonasal pathway

The pathway through which odorant molecules enter the nose via the nostrils.

Retronasal pathway

The pathway through which odorant molecules enter the nose from the oral cavity via the pharynx.

Nasal septum

The structure that separates the two nasal cavities.

Turbinates

Bony knots of tissue in the nose that direct air towards the olfactory epithelium.

Olfactory epithelium

Tissue containing olfactory receptor neurons (ORNs) responsible for detecting odors.

Cilia

Hair-like structures on olfactory receptor neurons that extend into olfactory mucus.

Axons of ORNs

Fibers that form the olfactory nerve and transmit signals from the olfactory receptors to the brain.

Bowman's gland

Gland that produces olfactory mucus to dissolve odorants.

G-Protein Coupled Receptors

A class of receptors that, when activated by binding a ligand, trigger cellular responses.

Population coding

The mechanism by which ORNs respond to odorants, allowing for the discrimination of more odors than there are types of ORNs.

Mitral cells

Neurons in the olfactory bulb that receive input from olfactory receptor neurons.

Tufted cells

A type of neuron in the olfactory bulb that also receives input from olfactory receptor neurons.

Glomeruli

Structures in the olfactory bulb where axons of ORNs synapse with mitral and tufted cells.

Chemotopy

The spatial organization of neurons based on the types of molecules they respond to.

Olfactory tract

The pathway through which signals from the olfactory bulb are sent to other brain areas.

Limbic system

Part of the brain involved in emotion and memory, influenced by olfactory input.

Amygdala

A brain structure involved in emotion, notably the emotional response to odors.

Piriform cortex

Part of the brain responsible for processing olfactory information.

Entorhinal cortex

Region of the brain serving as a gateway to the hippocampus and involved in memory.

Hippocampus

Brain structure associated with memory formation, influenced by olfactory signals.

Concentration

Measured as the number of molecules of a substance per million molecules of air (ppm).

Detection threshold

The concentration level at which an odor can be identified 75% of the time.

Adaptation to odors

A decrease in sensitivity to an odor after prolonged exposure.

Flavor

The full sensory experience of ingesting food, including taste and odor.

Trigeminal sense

Sensory pathway that detects irritants in the mouth and contributes to the mouthfeel of food.

Taste

The perception created by tastants, molecules that stimulate taste receptors.

Tastants

Molecules that evoke taste sensations, including sweet, salty, sour, bitter, and umami.

Taste receptor cells

Cells that detect tastants and are sensitive to specific tastes.

Taste buds

Structures containing taste receptor cells, located on the surface of the tongue.

Papillae

Small structures on the tongue that contain taste buds.

Gustatory cortex

Region of the brain responsible for processing taste sensations.

Orbitofrontal cortex

Part of the brain involved in representing the reward value of food and flavor.

Emotional response to odor

The brain's reaction to smells, influenced by the limbic system.

Identification of odors

The process by which humans recognize and label specific smells.

Flavor perception

The subjective experience of flavor, influenced by sensory and cognitive factors.

Cognitive influences on flavor

The effect of expectations and context on flavor perception.

Supertasters

Individuals with a heightened sensitivity to certain tastes, particularly bitter.

Bitter receptor types

Variations in the T2R38 gene affecting sensitivity to bitter tastes.

Influence of training on odor identification

The improvement of odor identification skills through experience and practice.

Cross-adaptation

The phenomenon where adaptation to one odor affects the perception of similar odors.

Sensitivity to odors

The ability to detect and identify different smells, often varies with context.

Vivid memories evoked by odors

The tendency for smells to trigger strong recollections of past experiences.

Memory association with odors

The connection between specific smells and emotional or experiential memories.

Strong odorants

Odor substances that can be detected at low concentrations (ppm).

Weak odorants

Odor substances that require higher concentrations for detection.