The Chemical Senses: Taste and Smell

Vocabulary terms and definitions covering the chemical senses of gustation and olfaction, their evolutionary purposes, and related neuroanatomy.

Gustation

The formal psychological term for the sense of taste, which primarily serves as a warning sign and for safety.

Olfaction

The formal psychological term for the sense of smell, which functions as a warning sign and for safety similar to taste.

Chemical Senses

The classification for taste and smell because they rely on receptors that catch chemicals from food or smell particles.

The Five Main Taste Receptors

Taste buds focused on the specific qualities of salty, sweet, sour, bitter, and umami.

Evolutionary preference for Sweet and Salty

A biological inclination where these tastes are perceived as safe and nutrient-rich.

Evolutionary avoidance of Bitter and Sour

A biological survival mechanism where these tastes signal potential poison or death.

Smell and Bonding

The emotional capacity of olfaction that allows babies to recognize a parent's smell within the first few months.

Smell and Memory

The unique characteristic of olfaction to trigger memories because it bypasses the thalamus and goes directly to the limbic system.

Thalamus

Known as the sensory switchboard, it sends sensory information to the correct part of the brain, but it is not utilized by the sense of smell.

Hippocampus

A part of the limbic system responsible for managing the storage and retrieval of memories.

Amygdala

A part of the limbic system that triggers emotional responses such as fear and anger.

Hypothalamus

The brain's reward center that uses hormones to maintain homeostasis and keep the body in balance.

Corpus callosum

The structure that connects and coordinates communication between the two brain hemispheres.

Transduction

The process of converting external stimuli into neural signals, occurring in the retina for sight and the cochlea for hearing.

Cochlea

The part of the ear where sound wave transduction occurs.

Iris

A structure of the eye located between the cornea and the lens, surrounding the pupil.

Epithelium

The area in the nasal cavity that contains the olfactory receptors.