What is chemoreception?

Chemoreception is how organisms respond to chemical stimuli in their environments, primarily through taste and smell. It relies on chemicals acting as signals to regulate cell function without being metabolized within the cell. These signals can originate internally, like hormones, or externally, eliciting responses from entire organisms, including animals and microorganisms. Taste, or gustation, and smell, or olfaction, are the two commonly recognized chemosensory systems. Animals use chemoreception to detect mates or food from a distance, identify chemicals produced by plants or predators, and communicate via pheromones. Humans apply their knowledge of chemoreception to modify their behavior and that of other animals, often to manage pests using pheromones in traps or to confuse mating patterns.

How do animals use chemoreception to sense chemicals?

Animals use chemoreception to sense chemicals in their environment through taste and smell. Volatile compounds are perceived through the olfactory system, while nonvolatile chemicals are perceived through taste or the vomeronasal organ. To produce a behavioral response, a chemical must create a signal in the nervous system by interacting with receptor cells. This interaction leads to changes in the cell's electrical charge, generating a nerve impulse. The electrical signal travels along neurons as action potentials initiated by electrical changes in receptor cells. A chemical must cause specific ion channels to open, often involving receptor proteins in the cell membrane.

What are the main types of chemoreceptors in the body?

The two main types of chemoreceptors are arterial and central. Arterial chemoreceptors monitor oxygen and carbon dioxide levels in arterial blood, while central chemoreceptors, located in the brain, respond to changes in carbon dioxide levels in their immediate environment. Arterial chemoreceptors include the carotid and aortic bodies. The carotid bodies are located in the neck and respond to changes in the partial pressure of oxygen and carbon dioxide in arterial blood. The aortic bodies are near the aorta and primarily respond to changes in oxygen partial pressure. Central chemoreceptors are found near the medulla and respond to changes in the partial pressure of carbon dioxide.

How does chemoreception help with taste and smell?

Chemoreception enables organisms to respond to chemical stimuli, relying on taste and smell. In taste, receptor cells in taste buds interact with chemicals, producing electrical signals. Taste modalities include sweet, salt, sour, bitter, and umami, informing animals about nutrient content and potential dangers. In smell, a chemical must produce a signal in the nervous system, initiating processes at receptor cells. The molecule interacts with the cell surface, causing reactions that change cellular electrical charge and generate a nerve impulse. This transformation of an external stimulus into a cellular response is known as signal transduction.

How do chemoreceptors transmit information to the brain?

Chemoreceptors, crucial for chemoreception , identify chemical stimuli, triggering a signal in the nervous system that leads to a behavioral response. This process begins with a molecule being captured in a layer of mucus, then interacting with the receptor cell surface to spark reactions inside the cell. These reactions alter the cell's electrical charge, creating a nerve impulse. This transformation, known as signal transduction, involves electrical signals called action potentials, initiated by chemical-induced electrical changes in receptor cells. The brain uses these signals to detect changes in metabolic rate and adjust ventilation accordingly.

Why is chemoreception important for survival and maintaining body balance?

Chemoreception is crucial for survival because it allows organisms to respond to chemical stimuli in their environments, which is vital for finding food, avoiding predators, and maintaining internal balance. Chemoreceptors detect changes in blood oxygen and carbon dioxide levels, which helps regulate breathing patterns and maintain appropriate ventilation. Detecting chemical cues from predators allows animals to escape danger, while identifying food sources ensures proper nutrient intake. This process involves both taste and smell, enabling organisms to adjust their behavior and physiology to maintain homeostasis and overall well-being.

Chemoreception

Introduction
The senses of taste and smell
- Taste
- Smell
- Interaction between taste and smell
- Cellular mechanisms in chemoreception
  - Perireceptor events
  - Signal transduction
- Processing olfactory information
Chemoreception in different organisms
- Single-celled organisms
- Specialized chemosensory structures
- Animals with separate taste and olfactory systems
  - Arthropods
  - Vertebrates
    - Fish
    - Terrestrial vertebrates
Behavior and chemoreception
- Pheromones
  - Pheromone perception
  - Primer pheromones
- Movement toward an odor source
- Reproductive behavior
  - Insects
    - Sex-attractant pheromones
    - Aphrodisiac pheromones
    - Sex recognition
  - Mammals
- Territorial behavior
- Individual recognition
- Homing
- Finding and recognizing food
  - Plant chemicals
  - Attraction
  - Phagostimulation
  - Deterrents and repellents
  - Feeding decisions
  - Blood-feeding insects
- Chemical defense
  - Defensive odors
  - Defensive tastes
  - Predator chemical cues and prey escape
- Effects of experience
  - Early experience
  - Associative learning
- Influence of chemoreception in humans
  - Food additives
  - Odor and culture
  - Human uses of chemoreception in other animals
    - Dogs
    - Monitoring and controlling pests
    - Altering pest behavior

References & Edit History Related Topics

Images & Videos

A pine grosbeak with pink and gray plumage perches on a branch, eating red berries among autumn foliage.

Diagram showing the chemical transmission of nerve impulses at a synapse, with labeled steps illustrating neurotransmitter release from the presynaptic terminal, movement across the synaptic cleft, binding to postsynaptic channel receptors, and resulting signal propagation in the nervous system.

Do Different Parts of the Tongue Taste Different Flavors?

Why does toothpaste make orange juice taste bad?

Two anatomical illustrations of the human tongue: the left shows a close-up of the tongue's surface with a magnified view of papillae, while the right displays a labeled cross section of the tongue in the mouth, highlighting its position relative to the teeth, lips, roof of mouth, lower jawbone, and air passage.

Cross-section diagram of the olfactory epithelium in the nasal cavity, showing labeled structures including olfactory receptor cells, supporting cells, basal cells, Bowman's gland, olfactory nerve fibers, cilia, and odor molecules.

Illustration showing the side view of a cat's head with its brain highlighted, alongside a labeled diagram of the cat brain identifying the olfactory bulb, cerebrum, and cerebellum.

Illustration showing the brain structure of a caiman, with a side view of the reptile's head highlighting the brain's location and a labeled diagram identifying the olfactory bulb, cerebrum, optic lobe, cerebellum, and pituitary.

At a Glance

chemoreception summary

Chemoreception

physiology

Written by

Elizabeth BernaysAll

Fact-checked by

Britannica Editors

Last updated

Nov. 6, 2026 •History

Top Questions

What is chemoreception?
Chemoreception is how organisms respond to chemical stimuli in their environments, primarily through taste and smell. It relies on chemicals acting as signals to regulate cell function without being metabolized within the cell. These signals can originate internally, like hormones, or externally, eliciting responses from entire organisms, including animals and microorganisms.

Taste, or gustation, and smell, or olfaction, are the two commonly recognized chemosensory systems. Animals use chemoreception to detect mates or food from a distance, identify chemicals produced by plants or predators, and communicate via pheromones. Humans apply their knowledge of chemoreception to modify their behavior and that of other animals, often to manage pests using pheromones in traps or to confuse mating patterns.
2 Britannica Sources
1. chemoreception
2. human respiratory system: Peripheral chemoreceptors
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How do animals use chemoreception to sense chemicals?
Animals use chemoreception to sense chemicals in their environment through taste and smell. Volatile compounds are perceived through the olfactory system, while nonvolatile chemicals are perceived through taste or the vomeronasal organ.

To produce a behavioral response, a chemical must create a signal in the nervous system by interacting with receptor cells. This interaction leads to changes in the cell's electrical charge, generating a nerve impulse. The electrical signal travels along neurons as action potentials initiated by electrical changes in receptor cells. A chemical must cause specific ion channels to open, often involving receptor proteins in the cell membrane.
1 Britannica Source
1. chemoreception
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What are the main types of chemoreceptors in the body?
The two main types of chemoreceptors are arterial and central. Arterial chemoreceptors monitor oxygen and carbon dioxide levels in arterial blood, while central chemoreceptors, located in the brain, respond to changes in carbon dioxide levels in their immediate environment.

Arterial chemoreceptors include the carotid and aortic bodies. The carotid bodies are located in the neck and respond to changes in the partial pressure of oxygen and carbon dioxide in arterial blood. The aortic bodies are near the aorta and primarily respond to changes in oxygen partial pressure.

Central chemoreceptors are found near the medulla and respond to changes in the partial pressure of carbon dioxide.
2 Britannica Sources
1. Definition of chemoreceptor
2. human respiratory system: Peripheral chemoreceptors
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How does chemoreception help with taste and smell?
Chemoreception enables organisms to respond to chemical stimuli, relying on taste and smell. In taste, receptor cells in taste buds interact with chemicals, producing electrical signals. Taste modalities include sweet, salt, sour, bitter, and umami, informing animals about nutrient content and potential dangers.

In smell, a chemical must produce a signal in the nervous system, initiating processes at receptor cells. The molecule interacts with the cell surface, causing reactions that change cellular electrical charge and generate a nerve impulse. This transformation of an external stimulus into a cellular response is known as signal transduction.
1 Britannica Source
1. chemoreception
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How do chemoreceptors transmit information to the brain?
Chemoreceptors, crucial for chemoreception, identify chemical stimuli, triggering a signal in the nervous system that leads to a behavioral response. This process begins with a molecule being captured in a layer of mucus, then interacting with the receptor cell surface to spark reactions inside the cell.

These reactions alter the cell's electrical charge, creating a nerve impulse. This transformation, known as signal transduction, involves electrical signals called action potentials, initiated by chemical-induced electrical changes in receptor cells. The brain uses these signals to detect changes in metabolic rate and adjust ventilation accordingly.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Why is chemoreception important for survival and maintaining body balance?
Chemoreception is crucial for survival because it allows organisms to respond to chemical stimuli in their environments, which is vital for finding food, avoiding predators, and maintaining internal balance.

Chemoreceptors detect changes in blood oxygen and carbon dioxide levels, which helps regulate breathing patterns and maintain appropriate ventilation. Detecting chemical cues from predators allows animals to escape danger, while identifying food sources ensures proper nutrient intake. This process involves both taste and smell, enabling organisms to adjust their behavior and physiology to maintain homeostasis and overall well-being.
2 Britannica Sources
1. chemoreception
2. human respiratory system: Peripheral chemoreceptors
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Chemoreception, process by which organisms respond to chemical stimuli in their environments that depends primarily on the senses of taste and smell. Chemoreception relies on chemicals that act as signals to regulate cell function, without the chemical necessarily being taken into the cell for metabolic purposes. While many chemicals, such as hormones and neurotransmitters, occur within organisms and serve to regulate specific physiological activities, chemicals in the external environment are also perceived by and elicit responses from whole organisms. All animals and microorganisms such as bacteria exhibit this latter type of chemoreception, but the two commonly recognized chemosensory systems are the senses of taste, or gustation, and smell, or olfaction.

The following article discusses the role of taste and smell and the interaction of these two sensory systems in chemoreception. For basic information about the different senses used by animals, see sensory reception. For information on specific senses, see also photoreception, thermoreception, and mechanoreception.