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Information about Olfactory Nerve

Nerve:
Latinnervus olfactorius
subject #196
MeSH Olfactory+Nerve
The olfactory nerve, or cranial nerve I, is the first of twelve cranial nerves. The specialized olfactory receptor neurons of the olfactory nerve are located in the olfactory mucosa of the upper parts of the nasal cavity. The olfactory nerve consists of a collection of sensory nerve fibers that extend from the olfactory epithelium to the olfactory bulb, passing through the many openings of the cribriform plate, a sieve-like structure.

Olfactory receptor neurons continue to be born throughout life and extend new axons to the olfactory bulb. Olfactory ensheathing glia wrap bundles of these axons and are thought to facilitate their passage into the central nervous system.

The sense of smell (olfaction) arises from the stimulation of the olfactory receptors by activation from gas molecules that pass by the nose during respiration. The resulting electrical activity is transduced into the olfactory bulb which then transmits the electrical activity to other parts of the olfactory system and the rest of the central nervous system via the olfactory tract.

The olfactory nerve is the shortest of all the twelve cranial nerves and only one of two cranial nerves (the other being the optic nerve) that do not join with the brainstem.

Testing the Olfactory nerve

To test the function of the olfactory nerve, doctors block one of the patient's nostrils and place a pungent odor (such as damp coffee essence) under the open nostril. The test to see if the patient can detect the smell is then repeated on the other nostril.

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See also

External links

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Nerves of head and neck: the cranial nerves
I-IVolfactory • optic • oculomotor (superior branch, inferior branch) • trochlear
V: trigeminaltrigeminal ganglion • ophthalmic • maxillary • mandibular
VI: abducensno significant branches
VII: facialnervus intermedius • geniculate • inside facial canal (greater petrosal, nerve to the stapedius, chorda tympani) • at exit from stylomastoid foramen (posterior auricular, digastric • stylohyoid) • on face (temporal, zygomatic, buccal, mandibular, cervical)
VIII: vestibulocochlearcochlear (striae medullares, lateral lemniscus) • vestibular (Scarpa's ganglion)
IX: glossopharyngealnucleus ambiguus • ganglia (superior, petrous) • tympanic (tympanic plexus, lesser petrosal) • carotid sinus • pharyngeal branches • pharyngeal plexus
X: vagusganglia (jugular, nodose) • Alderman's nerve • in the neck (pharyngeal branch, superior laryngeal ext and int, recurrent laryngeal) • in the thorax (pulmonary branches, esophageal plexus) • in the abdomen (gastric plexuses, celiac plexus, gastric plexus)
XI-XIIaccessory • hypoglossal


 •  • [ e]
Sensory system: Olfactory system/Olfaction
Olfactory bulb • Olfactory nerve • Olfactory epithelium • Glomeruli • Olfactory mucosa • Olfactory receptor neurons • Mitral cells • Piriform cortex
Rhinencephalon • Olfactory tract • Olfactory trigone
Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed
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Cranial nerves are nerves that emerge directly from the brain in contrast to spinal nerves which emerge from segments of the spinal cord. Although thirteen cranial nerves in humans fit this description, twelve are conventionally recognized.
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Location olfactory epithelium in the nose
Function Detect traces of chemicals in inhaled air (sense of smell)
Neurotransmitter Glutamate
Morphology Bipolar sensory receptor
Presynaptic connections None
Postsynaptic connections
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The mucous membranes (or mucosae; singular: mucosa) are linings of mostly endodermal origin, covered in epithelium, and are involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organs.
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The nasal cavity (or nasal fossa) is a large air-filled space above and behind the nose in the middle of the face.

Function

The nasal cavity conditions the air to be received by the areas of the respiratory tract.
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The olfactory bulb is a structure of the vertebrate forebrain involved in olfaction, the perception of odors.

Anatomy

In most vertebrates, the olfactory bulb is the most rostral (forward) part of the brain.
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In general, a sieve separates wanted/desired elements from unwanted material using a tool such as a mesh, net or other filtration or distillation methods. The word "sift" derives from this term.
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Location olfactory epithelium in the nose
Function Detect traces of chemicals in inhaled air (sense of smell)
Neurotransmitter Glutamate
Morphology Bipolar sensory receptor
Presynaptic connections None
Postsynaptic connections
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The olfactory bulb is a structure of the vertebrate forebrain involved in olfaction, the perception of odors.

Anatomy

In most vertebrates, the olfactory bulb is the most rostral (forward) part of the brain.
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Olfaction (also known as olfactics) refers to the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertbrates, and, by analogy, sensory cells of the antennae of invertebrates.
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In physiology, transduction is the conversion of a stimulus from one form to another.

Transduction in the nervous system typically refers to synaptic events wherein an electrical signal, known as an action potential, is converted into a chemical one via the release of
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The olfactory system is the sensory system used for olfaction. Most mammals and reptiles have two distinct parts to their olfactory system: a main olfactory system and an accessory olfactory system.
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The central nervous system (CNS) represents the largest part of the nervous system, including the brain and the spinal cord. Together with the peripheral nervous system, it has a fundamental role in the control of behavior.
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Optic Nerve may be a reference to:
  • Optic nerve, the anatomical structure;
  • Optic Nerve (comic), the comic book series;
  • Optic Nerve (1998), the seminal release from the Irish hip hop act known as Exile Eye; or

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The brain stem is the lower part of the brain, adjoining and structurally continuous with the spinal cord. Most sources consider the pons, medulla oblongata, and midbrain all to be part of the brainstem.
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The anterior olfactory nucleus (AON; also called the anterior olfactory cortex) is a portion of the forebrain of vertebrates. It is found behind the olfactory bulb and in front of the piriform cortex (laterally) and olfactory tubercle (medially) in a region often referred to as
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Yale School of Medicine at Yale University is a private medical school located in New Haven, Connecticut, U.S. It was founded in 1810 as The Medical Institution of Yale College, and formally opened in 1813. The primary teaching hospital for the school is Yale-New Haven Hospital.
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Georgetown University is a private, Jesuit, research university, located in Washington, D.C.'s Georgetown neighborhood. Father John Carroll founded the school in 1789, though its roots extend back to 1634.
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A nerve is an enclosed, cable-like bundle of axons (the long, slender projection of a neuron). Neurons are sometimes called nerve cells, though this term is technically imprecise since many neurons do not form nerves, and nerves also include the glial cells that
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Head and neck anatomy focuses on the structures of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat.
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Cranial nerves are nerves that emerge directly from the brain in contrast to spinal nerves which emerge from segments of the spinal cord. Although thirteen cranial nerves in humans fit this description, twelve are conventionally recognized.
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Optic Nerve may be a reference to:
  • Optic nerve, the anatomical structure;
  • Optic Nerve (comic), the comic book series;
  • Optic Nerve (1998), the seminal release from the Irish hip hop act known as Exile Eye; or

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The oculomotor nerve is the third of twelve paired cranial nerves. It controls most of the eye movements (cranial nerves IV and VI also do some), constriction of the pupil, and holding the eyelid open.
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The superior branch of the oculomotor nerve or the superior division, the smaller, passes medialward over the optic nerve.

It supplies the Superior rectus and Levator palpebrae superioris.
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The inferior branch of the oculomotor nerve or the inferior division, the larger, divides into three branches.
  • One passes beneath the optic nerve to the medial rectus.
  • Another, to the inferior rectus.

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The trochlear nerve (the fourth cranial nerve, also called the fourth nerve or simply IV) is a motor nerve (a “somatic efferent” nerve) that innervates a single muscle: the superior oblique muscle of the eye.
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The trigeminal nerve (the fifth cranial nerve, also called the fifth nerve or simply V) is responsible for sensation in the face. It is similar to the spinal nerves C2–S5, which are responsible for sensation in the rest of the body.
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The trigeminal ganglion (or Gasserian ganglion, or semilunar ganglion) is a sensory ganglion of the trigeminal nerve which occupies a cavity (Meckel's cave) in the dura mater covering the trigeminal impression near the apex of the petrous part of the temporal bone.
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The ophthalmic nerve is one of the three branches of the trigeminal nerve, the fifth cranial nerve. Like the maxillary branch of the trigeminal nerve, the ophthalmic branch carries sensory fibers only.
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