Nasal cavity

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Nasal cavity

The nasal cavity (or nasal fossa) is a large air-filled space above and behind the nose

Nose

Anatomically, a nose is a protuberance in vertebrates that houses the nostrils, or nares, which admit and expel air for Respiration in conjunction with the mouth....
in the middle of the face.

nasal cavity conditions the air to be received by the areas of the respiratory tract

Respiratory tract

In humans the respiratory tract is the part of the anatomy that has to do with the process of Respiration .The respiratory tract is divided into 3 segments:...
and nose. Owing to the large surface area provided by the conchae

Turbinate

In anatomy, a nasal concha is a long, narrow and curled bone shelf which protrudes into the breathing passage of the nose. Turbinate bone refers to any of the scrolled spongy bones of the Nasal Cavity in vertebrates....
, the air passing through the nasal cavity is warmed or cooled to within 1 degree of body temperature. In addition, the air is humidified, and dust and other particulate matter is removed by vibrissae, short, thick hairs, present in the vestibule

Nasal vestibule

Nasal Vestibule is the most anterior part of the nasal cavity. It's enclosed by the cartilage of nose and lined by the same epithelium of the skin....
.

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Encyclopedia

The nasal cavity (or nasal fossa) is a large air-filled space above and behind the nose

Nose

Anatomically, a nose is a protuberance in vertebrates that houses the nostrils, or nares, which admit and expel air for Respiration in conjunction with the mouth....
in the middle of the face.

Function

The nasal cavity conditions the air to be received by the areas of the respiratory tract

Respiratory tract

Turbinate

Nasal vestibule

Nasal Vestibule is the most anterior part of the nasal cavity. It's enclosed by the cartilage of nose and lined by the same epithelium of the skin....
. The cilia of the respiratory epithelium

Respiratory epithelium

Respiratory epithelium is a type of epithelium found lining the respiratory tract, where it serves to moisten and protect the airways. It also functions as a barrier to potential pathogens and foreign particles, preventing infection and tissue injury by action of the #mucociliary escalator....
move the particulate matter towards the pharynx where it is digested.

Borders

The lateral wall of the nasal cavity is mainly made up by the maxilla

Maxilla

The maxilla is a fusion of two bones along the palate fissure that form the upper jaw. This is similar to the mandible, which is also a fusion of two halves at the mental symphysis....
, however there is a deficiency that is compensated by: the perpendicular plate of the palatine bone

Palatine bone

The palatine bone is a bone in many species of the animal kingdom, commonly termed the palatum ....
, the medial pterygoid plate

Medial pterygoid plate

The medial pterygoid plate of the sphenoid is narrower and longer than the lateral pterygoid plate; it curves lateralward at its lower extremity into a hook-like process, the pterygoid hamulus, around which the tendon of the Tensor veli palatini glides....
, the labyrinth of the ethmoid

Labyrinth of ethmoid

The Labyrinth or Lateral Mass of the ethmoid bone consists of a number of thin-walled cellular cavities, the ethmoidal cells, arranged in three groups, anterior, middle, and posterior, and interposed between two vertical plates of bone; the lateral plate forms part of the orbit, the medial, part of the corresponding nasal cavity....
and the inferior concha. The nasal cavity is enclosed by the nasal bone

Nasal bone

The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, "the bridge" of the nose....
above. The floor of the nasal cavity, which forms the roof of the mouth, is made up by the bones of the hard palate: the horizontal plate of the palatine bone posteriorly and the palatine process of the maxilla anteriorly. To the front of the nasal cavity is the nose, while the back is continuous with the pharynx

Pharynx

FunctionsThe pharynx is part of the digestive system and respiratory system of many organisms.Because both food and Earth's atmosphere pass through the pharynx, a flap of connective tissue called the epiglottis closes over the trachea when food is swallowed to prevent choking or Pulmonary aspiration....
. The paranasal sinus

Paranasal sinus

Paranasal sinuses are air-filled spaces, communicating with the nasal cavity, within the bones of the skull and face....
es are connected to the nasal cavity through small orifices called ostia.

The nasal cavity is divided in two by a vertical fin called the nasal septum

Nasal septum

The nasal septum separates the left and right airways in the nose, dividing the two nostrils.It is Depression by the Depressor septi nasi muscle....
. On the sides of the nasal cavity are three horizontal outgrowths called turbinate

Turbinate

In anatomy, a nasal concha is a long, narrow and curled bone shelf which protrudes into the breathing passage of the nose. Turbinate bone refers to any of the scrolled spongy bones of the Nasal Cavity in vertebrates....
s or conchae (singular "concha"). These turbinates disrupt the airflow, directing air toward the olfactory epithelium

Olfactory epithelium

The olfactory epithelium is a specialized epithelium tissue inside the nasal cavity that is involved in olfaction. In humans, it measures about 2 cm by 5 cm long and lies on the roof of the nasal cavity about 3 inches above and behind the nostrils....
on the surface of the turbinates and the septum. The vomeronasal organ

Vomeronasal organ

The vomeronasal organ , or Jacobson's organ, is an auxiliary olfactory sense organ that is found in many animals. It was discovered by Ludvig Jacobson in 1813....
is located at the back of the septum and has a role in pheromone

Pheromone

A pheromone is a chemical that triggers a natural behavioral response in another member of the opposite gender of the same species. There are alarm signal pheromones, food trail pheromones, sex pheromones, and many others that affect behavior or physiology....
detection.

Cilia and mucus

Mucus

In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. It is a viscous colloid containing antiseptic enzymes and immunoglobulins that serves to protect Epithelium in the respiratory,...
along the inside wall of the nasal cavity trap and remove dust and pathogens from the air as it flows through the nasal cavity. The cilia move the mucus down the nasal cavity to the pharynx, where it can be swallowed.

The nasal cavity is divided into two segments: the respiratory segment and the olfactory segment. The respiratory segment is lined with ciliated pseudostratified columnar epithelium (also called respiratory epithelium). The conchae are located in this region. The respiratory segment has a very vascularized lamina propria allowing the venous plexuses of the conchal mucosa to engorge with blood, restricting airflow and causing air to be directed to the other side of the nose. This cycle occurs approximately every 20-30 minutes. Nose bleeds in the inferior concha are common in this region. The olfactory segment is lined with a specialized type of pseudostratified columnar epithelium, known as olfactory epithelium, which contains receptors for the sense of the smell. This segment is located along the dorsal roof of the nasal cavity. Histological sections appear yellowish-brown due to the presence of lipofuscin pigments. Olfactory mucosal cell types include: bipolar neurons, supporting (sustentacular) cells, basal cells, and Bowman's glands. The axons of the bipolar neurons form the olfactory nerve (cranial nerve I) which enters the brain through the cribiform plate. Bowman's glands are serous glands in the lamina propria, whose secretions trap and dissolve odoriferous substances.the nasal cavity also can be called the nostril.

Blood and nerve supply

There is a rich blood supply to the nasal cavity. In some animals, such as dog

Dog

The dog is a domesticated subspecies of the Gray Wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties....
s, the capillary

Capillary

Capillaries are the smallest of a body's blood vessels, measuring 5-10 micrometre in diameter, which connect arterioles and venules, and enable the interchange of water, oxygen, carbon dioxide, and many other nutrient and waste chemical substances between blood and surrounding tissue s....
beds flowing through the nasal cavity help cool the blood flow to the brain

Brain

The brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as cnidarian and echinoderm have a decentralized nervous system without a brain, while sponges lack any nervous system at all....
.

Blood supply comes from branches of both the internal

Internal carotid artery

In human anatomy, the internal carotid artery is a major artery of the head and neck that helps supply blood to the brain....
and external carotid artery

External carotid artery

In human anatomy, the external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it bifurcates into an internal and external branch....
, including branches of the facial artery

Facial artery

The facial artery is a branch of the external carotid artery that supplies structures of the face....
and maxillary artery. The named arteries of the nose are:

Sphenopalatine artery
Sphenopalatine artery

The sphenopalatine artery is an artery of the head, commonly known as the artery of epistaxis....
, a branch of the maxillary artery.
Anterior ethmoidal artery
Anterior ethmoidal artery

The anterior ethmoidal artery, also anterior ethmoid artery is an artery of the head....
, a branch of the ophthalmic artery
Ophthalmic artery

The ophthalmic artery is a branch of the internal carotid artery which supplies branches to supply the eye and other structures in the orbit . It enters the orbit together with the Optic nerve through the Optic canal....
Branches of facial artery
Facial artery

The facial artery is a branch of the external carotid artery that supplies structures of the face....
supplying the vestibule of the nasal cavity.

Innervation

Innervation of the nasal cavity responsible for the sense of smell is via the olfactory nerve

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....
, which sends microscopic fibers from the olfactory bulb

Olfactory bulb

The olfactory bulb is a structure of the vertebrate forebrain involved in olfaction, the perception of odors....
through the cribiform plate to reach the top of the nasal cavity.

General sensory innervation is by branches of the trigeminal nerve

Trigeminal nerve

The trigeminal nerve is responsible for sensation in the face. Sensory information from the face and body is processed by parallel pathways in the central nervous system....
(V₁ & V₂):

Nasociliary nerve
Nasociliary nerve

The nasociliary nerve is a branch of the ophthalmic nerve. It is intermediate in size between the two other main branches of the ophthalmic nerve, the frontal nerve and the lacrimal nerve, and is more deeply placed....
(V₁)
Nasopalatine nerve
Nasopalatine nerve

One branch of the posterior superior nasal branches , longer and larger than the others, is named the nasopalatine nerve .It enters the nasal cavity through the sphenopalatine foramen, passes across the roof of the nasal cavity below the orifice of the sphenoidal sinus to reach the septum, and then runs obliquely downward and forward betwee...
(V₂)
Posterior nasal branches of Maxillary nerve
Maxillary nerve

The maxillary nerve is one of the three branches of the Trigeminal nerve, the fifth cranial nerve. It comprises the principal functions of sensation from the maxillary, nasal cavity, sinus, the palate and subsequently that of the mid-face, and is intermediate, both in position and size, between the ophthalmic nerve and the mandibular nerve...
(V₂)

Contrary to what many other websites say, there are two passages in the nasal cavity, not to be confused with nostrils.The entire nasal cavity is innervated by autonomic fibers. Sympathetic

Sympathetic

The word sympathetic means different things in different contexts.* In neurology and neuroscience, the sympathetic nervous system is a part of the autonomic nervous system....
innervation to the blood vessels of the mucosa causes them to constrict

Vasoconstriction

Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries, arterioles and veins....
, while parasympathetic innervation of the mucosa controls secretion by mucous glands.

Diseases

Diseases of the nasal cavity include viral

Virus

A virus is a Optical microscope#Limitations of light microscopes infectious agent that is unable to grow or reproduce outside a host cell . Viruses infect all cellular life....
infections and nasal cavity cancer

Cancer

Cancer is a class of diseases in which a group of cell display uncontrolled growth , invasion , and sometimes metastasis . These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, do not invade or metastasize....
.

Empty nose syndrome

Empty nose syndrome

Empty nose syndrome is a medical term used by otolaryngologists to describe a nose crippled by over resection of the middle or inferior turbinates of the nose....
.

Nasal cavity

Function

Borders

Blood and nerve supply

Innervation

Diseases

Additional images

See also

External links