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Encyclopedia > Olfactory cortex

The olfactory system is the sensory system used for olfaction. The accessory olfactory system senses pheromones. The olfactory system is often spoken of along with the gustatory system as the chemosensory senses because both transduce chemical signals into perception. Linda B. Buck and Richard Axel won the 2004 Nobel Prize in Physiology or Medicine for their work on the olfactory system. This article or section may be confusing for some readers, and should be edited to be clearer or more simplified. ... Olfaction, the sense of odor (smell), is the detection of chemicals dissolved in air (or in water, by animals that live under water). ... Fanning honeybee exposes Nasonov gland (white-at tip of abdomen) releasing pheromone to entice swarm into an empty hive A pheromone is any chemical produced by a living organism that transmits a message to other members of the same species. ... The gustatory system is the sensory system that uses taste buds (or lingual papillae) on the upper surface of the tongue to provide information about the taste of food being eaten. ... In physiology, transduction is the conversion of a stimulus from one form to another. ... PSYCHOLOGY In psychology and the cognitive sciences, perception is the process of acquiring, interpreting, selecting, and organizing sensory information. ... Linda B. Buck, Ph. ... Richard Axel, M.D. (born July 2, 1946, New York City) is an American scientist whose work on the olfactory system won him and Linda B. Buck, then a post-doctoral scientist in his research group, the Nobel Prize in Physiology or Medicine in 2004. ... 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... List of Nobel Prize laureates in Physiology or Medicine from 1901 to the present day. ...


Anatomy

The olfactory system is made up of a number of different areas of the brain. Here is a partial list of some of the brain structures involved in vertebrates: Comparative brain sizes In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ... Typical classes Petromyzontidae (lampreys) Placodermi - extinct Chondrichthyes (cartilaginous fish) Acanthodii - extinct Actinopterygii (ray-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) Amphibia (amphibians) Reptilia (reptiles) Aves (birds) Mammalia (mammals) Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ...

In insects: An olfactory receptor neuron, also called an olfactory sensory neuron, is the primary transduction cell for olfaction in the olfactory system. ... The olfactory epithelium is a specialized epithelial tissue inside the nasal cavity that is involved in smell. ... The nasal cavity (or nasal fossa) is a large air-filled space above and behind the nose in the middle of the face. ... The olfactory epithelium is a specialized epithelial tissue inside the nasal cavity that is involved in smell. ... The nasal cavity (or nasal fossa) is a large air-filled space above and behind the nose in the middle of the face. ... The vomeronasal organ (VNO) or Jacobsons organ (sometimes misspelled Jacobsens) is an auxiliary olfactory sense organ in some vertebrates, all of which are tetrapods. ... The olfactory nerve is the first of twelve cranial nerves. ... Vesalius Fabrica, 1543. ... In anatomy of animals, the piriform cortex, or pyriform cortex is a region in the brain. ... Location of the amygdala in the human brain The amygdala (Latin, corpus amygdaloideum) is an almond-shaped set of neurons located deep in the brains medial temporal lobe. ... The entorhinal cortex (EC) is an important memory center in the brain. ... Orders Subclass Apterygota Symphypleona - globular springtails Subclass Archaeognatha (jumping bristletails) Subclass Dicondylia Monura - extinct Thysanura (common bristletails) Subclass Pterygota Diaphanopteroidea - extinct Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Blattodea (cockroaches) Mantodea (mantids) Isoptera (termites) Zoraptera Grylloblattodea Dermaptera (earwigs) Plecoptera (stoneflies) Orthoptera (grasshoppers, crickets...

Antennae (singular antenna), are the paired appendages connecting to the first (and in crustaceans also to the second) segment of the head of the members of all subphyla of the arthropods except Chelicerata. ... Antennal Lobe is the deutocerebral neuropil of the insect which receive the input from the sensory neurons on the antenna. ... The mushroom bodies or corpora pedunculata are a pair of structures in the brain of insects and other arthropods. ... In the thoracic region, the postero-lateral part of the anterior column projects lateralward as a triangular field, which is named the lateral column (lateral cornu, lateral horn). ...

Function

The olfactory system must accomplish several tasks:

  • Create a representation of the odor
  • Determine the concentration of the odor
  • Distinguish a new odor from the background environmental odors
  • Identify the odor across different concentrations
  • Pair the odor with a memory of what the odor represents

To accomplish all of these functions, the olfactory system uses many areas of the brain. Representations of the odor may be encoded by space (a pattern of activated neurons across a given olfactory region corresponds to the odor), time (a pattern of action potentials by multiple neurons corresponds to the odor) or a combination of the two. Scientists debate whether the odor code is primarially temporal or spatial. Neurons (also called nerve cells) are the primary cells of the nervous system. ... A. A schematic view of an idealized action potential illustrates its various phases as the action potential passes a point on a cell membrane. ...

Vesalius' Fabrica, 1543. Human Olfactory bulbs and Olfactory tracts outlined in red

In mammals, odorants are inhaled through the nose where they contact the olfactory epithelium. Olfactory receptor neurons in the olfactory epithelium transduce molecular features of the odorants into electrical signals which then travel along the olfactory nerve into the olfactory bulb. Axons from the olfactory sensory neurons converge in the olfactory bulb to form tangles called glomeruli (singular glomerulus). Inside the glomulerus, the axons contact the dendrites of mitral cells and several other types of cells. Mitral cells send their axons to a number of brain areas, including the piriform cortex, the medial amygdala, and the entorhinal cortex. Image File history File links 1543,Vesalius'OlfactoryBulbs. ... Image File history File links 1543,Vesalius'OlfactoryBulbs. ... Andreas Vesalius (portrait from the Fabrica). ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are biologically classified as bipedal primates belonging to the mammalian species Homo sapiens (Latin for wise man or thinking man) under the family Hominidae (the great apes). ... Vesalius Fabrica, 1543. ... Human nose in profile You may be looking for Nose, a town in Japan, or The Nose, a story by Nikolai Gogol and an opera by Dmitri Shostakovich. ... The olfactory epithelium is a specialized epithelial tissue inside the nasal cavity that is involved in smell. ... An olfactory receptor neuron, also called an olfactory sensory neuron, is the primary transduction cell for olfaction in the olfactory system. ... The olfactory nerve is the first of twelve cranial nerves. ... Vesalius Fabrica, 1543. ... An axon, or nerve fiber, is a long slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... The glomerulus (plural glomeruli) in olfaction is structure in the olfactory bulb. ... The term Dendrite stems from the Greek word dendron (literally “tree”), and typically refers to the branched projections of a neuron that act to conduct the electrical stimulation received from other cells to and from the cell body, or soma of the neuron from which the dendrites project. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... In anatomy of animals, the piriform cortex, or pyriform cortex is a region in the brain. ... Location of the amygdala in the human brain The amygdala (Latin, corpus amygdaloideum) is an almond-shaped set of neurons located deep in the brains medial temporal lobe. ... The entorhinal cortex (EC) is an important memory center in the brain. ...

Amygdala location in each hemisphere of the human brain
Amygdala location in each hemisphere of the human brain

The piriform cortex is probably the area most closely associated with identifying the odor. The medial amygdala is involved in social functions such as mating and the recognition of animals of the same species. The entorhinal cortex is associated with memory. The exact functions of these higher areas are a matter of scientific research and debate. Image File history File links Location of the Amygdala in the Human Brain The figure shows the underside (ventral view) of a semi-transparent human brain, with the front of the brain at the top. ... Image File history File links Location of the Amygdala in the Human Brain The figure shows the underside (ventral view) of a semi-transparent human brain, with the front of the brain at the top. ... In anatomy of animals, the piriform cortex, or pyriform cortex is a region in the brain. ... Location of the amygdala in the human brain The amygdala (Latin, corpus amygdaloideum) is an almond-shaped set of neurons located deep in the brains medial temporal lobe. ... The entorhinal cortex (EC) is an important memory center in the brain. ...


Clinical implications

Damage to the olfactory system can occur by traumatic brain injury, cancer, inhalation of toxic fumes, or neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. These conditions can cause anosmia. Doctors can detect damage to the olfactory system by presenting the patient with odors via a scratch and sniff card or by having the patient close their eyes and try to identify commonly available odors like coffee or peppermint candy. Brain damage or brain injury is the destruction or degeneration of brain cells. ... When normal cells are damaged beyond repair, they are eliminated by apoptosis. ... Anosmia is the lack of olfaction, or a loss of the sense of smell. ...

Sensory system - Olfactory system - edit
Olfactory bulb | Olfactory nerve | Olfactory epithelium | Glomeruli | Olfactory mucosa | Olfactory receptor neurons | Mitral cells | Piriform cortex
Nervous system - Sensory system - edit
Special sensesVisual system | Auditory system | Olfactory system | Gustatory system
Somatosensory systemNociception | Thermoreception | Vestibular system |
Mechanoreception (Pressure, Vibration & Proprioception)

  Results from FactBites:
 
HHMI News: Researchers Discover Precise Olfactory Map (1218 words)
In the olfactory bulb, however, the axons of neurons with the same receptor converge in a few invariant glomeruli, creating a map of odor receptor inputs that is nearly identical in different individuals.
In contrast, the mice in which all olfactory neurons were engineered with BL showed labeling throughout the olfactory cortex.
The olfactory cortex is actually composed of several distinct brain structures, each of which may have a different function.
Piriform cortex - Wikipedia, the free encyclopedia (307 words)
In anatomy of animals, the piriform cortex, or pyriform cortex is a region in the brain.
Sometimes called the olfactory cortex, olfactory lobe or paleopallium, piriform cortical regions are present in the brains of amphibians, reptiles and mammals.
The piriform cortex is among three areas that emerge in the telencephalon of amphibians, situated caudally to a dorsal area, which is caudal to a hippocampal area.
  More results at FactBites »

 
 

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