The structure and functions of one of the main parts of the respiratory system: from the wings of the nose to the sinuses. Anatomy and physiology of the nose How the nose and sinuses work

The human nose is a sensory and respiratory organ that performs a number of important functions related to providing tissues with oxygen, speech formation, odor recognition and protecting the body from negative external factors. Next, we will take a closer look at the structure of the human nose and answer the question of what the nose is for.

General structure and functions

It is a unique part of the human body. In nature, there are no living creatures with such a construction of the nose. Even the closest relatives of people - monkeys - are very different both in appearance and internal structure, and in the principles of its work. Many scientists associate the way the nose is arranged, and the features of the development of the sense organ with upright posture and the development of speech.

The external nose can vary quite a lot depending on gender, race, age, and individual characteristics. As a rule, in women it has a smaller size, but wider than in men.

In groups of European peoples, leptorinia (a narrow and high sense organ) is more often observed, in representatives of the Negroid race, indigenous Australians and Melanesians, hamerinia (wider). However, the internal anatomy and physiology of the nose is the same in all people.

The human nose is the initial section of the upper respiratory system. It consists of three main segments:

• nasal cavity;
• outdoor area;
• adnexal voids communicating with the cavity through thin channels.

The most important functions of the nose, which give an answer to the question of why a person needs a nose:

The structure of the outer part

The external nose is located on the outer part of the face, is clearly visible and looks like a trihedral irregular pyramid. Its shape is created by bone, soft and cartilaginous tissues.

The bone section (back, root) is formed by paired nasal bones, which are connected to the nasal processes of the frontal bone and the frontal processes of the upper jaw adjacent to the side. It creates a fixed bone skeleton, to which a mobile cartilaginous section is attached, the components of which are:

• The paired lateral cartilage (cartilago nasi lateralis) has the shape of a triangle, takes part in the creation of the wing and back. With its posterior edge, it adjoins the beginning of the nasal bone (a hump is often formed there), with its inner edge it fuses with the cartilage of the opposite side of the same name, and with its lower edge - to the nasal septum.
• Paired large cartilage of the wing (cartilago alaris major), surrounds the entrance to the nostrils. It is divided into lateral (crus laterale) and medial (crus mediale) legs. The medial ones separate the nostrils and form the tip of the nose, the lateral ones, longer and wider, form the structure of the nasal wings and are complemented by 2-3 more small cartilages in the back sections of the wings.

All cartilages are connected to the bones and to each other by fibrous tissue and are covered by the perichondrium.

The external nose has mimic muscles located in the region of the wings, with the help of which people can narrow and widen the nostrils, raise and lower the tip of the nose. From above, it is covered with skin, in which there are many sebaceous glands and hairs, nerve endings and capillaries. Blood supply is carried out from the systems of the internal and external carotid arteries through the external and internal maxillary arteries. The lymphatic system is focused on the submandibular and parotid lymph nodes. Innervation - from the facial and 2 and 3 branches of the trigeminal nerve.

Due to its prominent location, the external nose is most often corrected by plastic surgeons, to whom people turn to in the hope of getting the desired result.

Correction can be carried out to align the hump at the junction of bone and cartilage, however, the main object of rhinoplasty is the tip of the nose. The operation in clinics can be performed both according to medical requirements and at the request of a person.

Common reasons for rhinoplasty:

• change in the shape of the top of the sense organ;
• reduction in the size of the nostrils;
• congenital defects and consequences of injuries;
• deviated septum and asymmetrical tip of the nose;
• violation of nasal breathing due to deformity.

It is also possible to correct the tip of the nose without surgery, using special Aptos threads or fillers based on hyaluronic acid, which are injected subcutaneously.

Anatomy of the nasal cavity

The nasal cavity is the initial segment of the upper respiratory tract. Anatomically located between the oral cavity, the anterior cranial fossa and the orbits. In the anterior part it goes to the surface of the face through the nostrils, in the posterior part - to the pharyngeal region through the choanae. Its inner walls are formed by bones, it is separated from the mouth by a hard and soft palate, and is divided into three segments:

• vestibule;
• respiratory area;
• olfactory area.

The cavity opens with a vestibule located next to the nostrils. From the inside, the vestibule is covered with a strip of skin 4-5 mm wide, equipped with numerous hairs (there are especially many of them in older men). Hairs are a barrier to dust, but often cause boils due to the presence of staphylococci in the bulbs.

The internal nose is an organ divided into two symmetrical halves by a bone and cartilage plate (septum), which is often curved (especially in men). Such a curvature is within the normal range, if it does not interfere with normal breathing, otherwise it has to be corrected surgically.

Each half has four walls:

• medial (internal) is a septum;
• lateral (external) - the most difficult. It consists of a number of bones (palatine, nasal, lacrimal, maxillary);
• upper - sigmoid plate of the ethmoid bone with holes for the olfactory nerve;
• lower - part of the upper jaw and the process of the palatine bone.

On the bone component of the outer wall, there are three shells on each side: upper, middle (on the ethmoid bone) and lower (independent bone). In accordance with the scheme of shells, nasal passages are also distinguished:

• Lower - between the bottom and the lower sink. Here is the exit of the lacrimal canal, through which the eye secretions drain into the cavity.
• Middle - between the lower and middle shells. In the region of the lunar fissure, first described by M.I. Pirogov, the outlet openings of most accessory chambers open into it;
• Upper - between the middle and upper shells, located behind.

In addition, there is a common course - a narrow gap between the free edges of all shells and the septum. The passages are long and winding.

The respiratory region is lined with a mucous membrane consisting of secretory goblet cells. Mucus has antiseptic properties and inhibits the activity of microbes; in the presence of a large number of pathogens, the volume of secretion secreted also increases. From above, the mucous membrane is covered with a cylindrical multi-row ciliated epithelium with miniature cilia. The cilia are constantly moving (flickering) towards the choanae and beyond the nasopharynx, which allows the removal of mucus with associated bacteria and foreign particles. If there is too much mucus and the cilia do not have time to evacuate it, then a runny nose (rhinitis) develops.

Under the mucosa is a tissue penetrated by a plexus of blood vessels. This makes it possible, by instantaneous swelling of the mucous membrane and narrowing of the passages, to protect the sense organ from stimuli (chemical, physical and psychogenic).

The olfactory region is located in the upper part. It is lined with epithelium, which contains receptor cells responsible for smell. Cells are spindle shaped. At one end they come to the surface of the membrane with vesicles with cilia, and at the other end they pass into the nerve fiber. The fibers are woven into bundles, forming the olfactory nerves. Fragrant substances interact with receptors through mucus, excite nerve endings, after which the signal enters the brain, where smells differ. A few molecules of the substance are enough to excite the receptors. A person is able to feel up to 10 thousand smells.

The structure of the paranasal sinuses

The anatomy of the human nose is complex and includes not only the sense organ itself, but also the voids (sines) that surround it, and with which it is in close interaction, connecting with the help of channels (orifices). The paranasal sinus system includes:

• wedge-shaped (main);
• maxillary (maxillary);
• frontal (frontal);
• cells of the ethmoid labyrinth.

The maxillary sinuses are the largest of all, their volume can reach 30 cubic centimeters. The chambers are located on the upper jaw between the teeth and the lower part of the orbits, they consist of five walls:

• The nasal is a bone plate that smoothly passes into the mucous membrane. The hole connecting with the nasal passage is located in its corner part. With a difficult outflow of secretions, an inflammatory process develops, called sinusitis.
• The facial one is palpable, the densest, covered with cheek tissues. Located in the canine fossa of the jaw.
• The orbital is the thinnest, it has a plexus of veins and an infraorbital nerve, through which the infection can pass to the eyes and the brain membrane.
• The posterior one goes to the maxillary nerve and maxillary artery, as well as the pterygopalatine node.
• The lower one adjoins the oral cavity, the roots of the teeth can protrude into it.

The frontal sinuses are located in the thickness of the frontal bone, between its anterior and posterior walls.

In newborns, it is absent, it begins to form from the age of 3, the process usually continues until the end of a person's sexual development. Approximately 5% of people have no frontal voids at all. The sinuses are made up of 4 walls:

• Orbital. Adjacent to the orbit, it has a long narrow connecting canal, with swelling of which frontitis develops.
• Facial - part of the frontal bone up to 8 mm thick.
• The medulla is adjacent to the dura mater and the anterior cranial fossa.
• The inner one divides the void into two chambers, often unequal.

The sphenoid sinus is located deep in the thickness of the bone of the same name, is divided by a septum into two parts of different sizes, each of which is independently connected to the upper course.

Like, and frontal voids, it is formed in children from the age of three and develops up to 25 years. This sinus is in contact with the cranial base, carotid arteries, optic nerves and pituitary gland, which can lead to serious inflammation. However, diseases of the sphenoid sinus are very rare.

The ethmoid sinus (labyrinth) consists of interconnected individual cells of the ethmoid bone, arranged in a row, 5-15 pieces on each side. Depending on the depth of the location, internal (go to the upper course), middle and front (connect to the middle course) are distinguished.

The nose is the initial section of the upper respiratory tract and is divided into the external nose and the nasal cavity with paranasal sinuses.

The external nose consists of bony, cartilaginous and soft parts and has the shape of an irregular trihedral pyramid. The root of the nose is distinguished - the upper section connecting it with the forehead, the back - the middle part of the nose, going down from the root, which ends with the tip of the nose. The lateral convex and movable surfaces of the nose are called the wings of the nose; their lower free edges form nostrils, or external openings.

The nose can be divided into 3 sections: 1) external nose; 2) nasal cavity; 3) paranasal sinuses.

The external nose is called an elevation resembling an irregular trihedral pyramid in shape, protruding above the level of the face and located along its midline. The surface of this pyramid is made up of two lateral slopes, which descend towards the cheeks and converge along the midline, forming here a rounded rib - the back of the nose; the latter is obliquely directed anteriorly and downwards. On the third, lower surface of the pyramid are two nasal openings - nostrils. The upper end of the back of the nose, which rests against the forehead, is called the root of the nose, or nose bridge. The lower end of the back of the nose, where it meets the lower surface, is called the tip of the nose. The lower, movable section of each lateral surface of the nose is called the ala of the nose.

The skeleton of the external nose consists of bones, cartilage and soft tissues. The composition of the external nose includes paired nasal bones, frontal processes of the maxillary bones and paired cartilages: the lateral cartilage of the nose, the large cartilage of the alar of the nose and the small cartilages located in the posterior part of the alar of the nose.

The skin on the bony part of the nose is mobile, on the cartilaginous part it is inactive. The skin contains many sebaceous and sweat glands with wide excretory openings, which are especially large on the wings of the nose, where the mouths of their excretory ducts are visible to the naked eye. Through the edge of the nasal opening, the skin passes to the inner surface of the nasal cavity. The strip that separates both nostrils and belongs to the nasal septum is called the movable septum. The skin in this place, especially in the elderly, is covered with hair, which delays the penetration of dust and other harmful particles into the nasal cavity.

The nasal septum divides the nasal cavity into two halves and consists of bone and cartilage parts. Its bony part is formed by the perpendicular plate of the ethmoid bone and the vomer. The quadrangular cartilage of the nasal septum enters the angle between these bone formations. To the front edge of the quadrangular cartilage adjoins the cartilage of the large wing of the nose, which is wrapped inwards. The anterior skin-cartilaginous section of the nasal septum, unlike the bone section, is mobile.

The muscles of the external nose in humans are rudimentary and have almost no practical significance. Of the muscle bundles that are of some importance, the following can be noted: 1) the muscle that lifts the wing of the nose - starts from the frontal process of the upper jaw and is attached to the posterior edge of the wing of the nose, partly passes into the skin of the upper lip; 2) narrowing the nasal openings and pulling down the wings of the nose; 3) a muscle that pulls the nasal septum down.

The vessels of the external nose are branches of the external maxillary and ophthalmic arteries and are directed towards the tip of the nose, which is rich in blood supply. The veins of the external nose drain into the anterior facial vein. The innervation of the skin of the external nose is carried out by the first and second branches of the trigeminal nerve, and the muscles - by the branches of the facial nerve.

The nasal cavity is located in the center of the facial skeleton and borders on top of the anterior cranial fossa, on the sides - on the eye sockets, and below - on the oral cavity. In front, it opens with nostrils located on the lower surface of the external nose, which have a variety of shapes. Posteriorly, the nasal cavity communicates with. the upper part of the nasopharynx through two adjacent oval-shaped posterior nasal openings, called choanae.

The nasal cavity communicates with the nasopharynx, with the pterygopalatine fossa, and with the paranasal sinuses. Through the Eustachian tube, the nasal cavity also communicates with the tympanic cavity, which determines the dependence of some ear diseases on the state of the nasal cavity. The close connection of the nasal cavity with the paranasal sinuses also causes the fact that diseases of the nasal cavity most often to one degree or another pass to the paranasal sinuses and through them can affect the cranial cavity and orbit with their contents. The topographic proximity of the cavity of the spit to the orbits and the anterior cranial fossa is a factor contributing to their combined damage, especially in trauma.

The nasal septum divides the nasal cavity into two not always symmetrical halves. Each half of the nasal cavity has an inner, outer, upper and lower wall. The nasal septum serves as the inner wall (Fig. 18, 19). The outer, or side, wall is the most complex. There are three protrusions on it, the so-called nasal conchas: the largest is the lower, middle and upper. The inferior nasal concha is an independent bone; the middle and upper shells are processes of the ethmoid labyrinth.

Rice. 18. Anatomy of the nasal cavity: lateral wall of the nose.
1 - frontal sinus; 2 - nasal bone; 3 - lateral cartilage of the nose; 4 - middle shell; 5 - middle nasal passage; 6 - lower sink; 7 - hard palate; 8 - lower nasal passage; 9 - soft palate; 10 - pipe roller; 11 - Eustachian tube; 12 - Rosenmuller's fossa; 13 - main sinus; 14 - upper nasal passage; 15 - upper shell; 16 - cockscomb.

Rice. 19. Medial wall of the nose.
1 - frontal sinus; 2 - nasal bone; 3 - perpendicular plate of the ethmoid bone; 4 - cartilage of the nasal septum; 5 - sieve plate; 6 - Turkish saddle; 7 - main bone; 8 - coulter.

Under each turbinate there is a nasal passage. Thus, between the lower concha and the bottom of the nasal cavity is the lower nasal passage, between the middle and lower shells and the side wall of the nose - the middle nasal passage, and above the middle shell - the upper nasal passage. In the anterior third of the lower nasal passage, approximately 14 mm from the anterior edge of the shell, is the opening of the lacrimal canal. In the middle nasal passage, they open with narrow openings: the maxillary (maxillary) sinus, the frontal sinus and the cells of the ethmoid labyrinth. Under the upper shell, in the area of ​​​​the upper nasal passage, the posterior cells of the ethmoid labyrinth and the main (sphenoidal) sinus open.

The nasal cavity is lined with a mucous membrane that continues directly into the paranasal sinuses. Two areas are distinguished in the mucous membrane of the nasal cavity: respiratory and olfactory. The olfactory region includes the mucous membrane of the upper shell, parts of the middle shell and the corresponding section of the nasal septum. The rest of the mucous membrane of the nasal cavity belongs to the respiratory region.

The mucous membrane of the olfactory region contains olfactory, basal and supporting cells. There are special glands that produce a serous secret, which contribute to the perception of olfactory irritation. The mucous membrane of the respiratory region is tightly soldered to the periosteum or perichondrium. The submucosal layer is absent. In some places, the mucous membrane thickens due to cavernous (cavernous) tissue. This occurs most frequently in the region of the inferior turbinate, the free edge of the middle turbinate, and also the elevation on the nasal septum corresponding to the anterior end of the middle turbinate. Under the influence of a variety of physical, chemical or even psychogenic moments, the cavernous tissue causes an instant swelling of the nasal mucosa. By slowing down the speed of blood flow and creating conditions for stagnation, the cavernous tissue favors the secretion and release of heat, and also regulates the amount of air entering the respiratory tract. The cavernous tissue of the inferior nasal concha is connected with the venous network of the mucous membrane of the lower part of the lacrimal canal. Swelling of the lower concha can therefore cause closure of the lacrimal canal and lacrimation.

The blood supply to the nasal cavity is carried out by branches of the internal and external carotid arteries. The ophthalmic artery departs from the internal carotid artery, entering the orbit and giving off the anterior and posterior ethmoid arteries there. From the external carotid artery departs the internal maxillary artery and the artery of the nasal cavity - the main palatine. The veins of the nasal cavity follow the arteries. The veins of the nasal cavity are also connected to the veins of the cranial cavity (hard and soft
meninges), and some flow directly into the sagittal sinus.

The main blood vessels of the nose pass in its posterior sections and gradually decrease in diameter towards the anterior sections of the nasal cavity. This is why bleeding from the back of the nose is usually more severe. In the initial part, directly at the entrance, the nasal cavity is lined with skin, the latter is bent inward and is equipped with hairs and sebaceous glands. The venous network forms plexuses that connect the veins of the nasal cavity with neighboring areas. This is important in connection with the possibility of infection spreading from the veins of the nasal cavity to the cranial cavity, orbit and to more distant areas of the body. Particularly important are venous anastomoses with a cavernous (cavernous) sinus located at the base of the skull in the region of the middle cranial fossa.

In the mucous membrane of the anteroinferior part of the nasal septum, there is the so-called Kisselbach place, which is distinguished by a rich arterial and venous network. The Kisselbach site is the most frequently traumatized site and is also the most common location for recurrent nosebleeds. Some authors (B. S. Preobrazhensky) call this place "the bleeding zone of the nasal septum." It is believed that bleeding here is more frequent because in this area there is a cavernous tissue with underdeveloped muscles, and the mucous membrane is more tightly attached and less extensible than in other places (Kisselbach). According to other data, the reason for the slight vulnerability of the vessels is the insignificant thickness of the mucous membrane in this area of ​​the nasal septum.

The innervation of the nasal mucosa is carried out by sensory branches of the trigeminal nerve, as well as branches emanating from the pterygopalatine node. From the latter, sympathetic and parasympathetic innervation of the nasal mucosa is also carried out.

The lymphatic vessels of the nasal cavity are connected with the cranial cavity. The outflow of lymph occurs partly to the deep cervical nodes and partly to the pharyngeal lymph nodes.

The paranasal sinuses include (Fig. 20) the maxillary, frontal, main sinuses and ethmoid cells.

Rice. 20. Paranasal sinuses.
a - front view; b - side view; 1 - maxillary (maxillary) sinus; 2 - frontal sinus; 3 - lattice labyrinth; 4 - main (sphenoidal) sinus.

The maxillary sinus is known as the maxillary sinus and is named after the anatomist who described it. This sinus is located in the body of the maxillary bone and is the most voluminous.

The sinus has the shape of an irregular quadrangular pyramid and has 4 walls. The anterior (facial) wall of the sinus is covered by the cheek and is palpable. The upper (orbital) wall is thinner than all the others. The anterior part of the upper wall of the sinus takes part in the formation of the upper opening of the lacrimal canal. The infraorbital nerve passes through this wall, which emerges from the bone in the upper part of the anterior wall of the sinus and branches in the soft tissues of the cheek.

The inner (nasal) wall of the maxillary sinus is the most important. It corresponds to the lower and middle nasal passages. This wall is pretty thin.

The lower wall (bottom) of the maxillary sinus is located in the region of the alveolar process of the upper jaw and usually corresponds to the alveoli of the posterior upper teeth.

The maxillary sinus communicates with the nasal cavity with one, and often two or more openings that lie in the middle nasal passage.

The frontal sinus is shaped like a trihedral pyramid. Its walls are as follows: front - anterior, posterior - border with the cranial cavity, lower - orbital, internal - forms a partition between the sinuses. Up the frontal sinus can rise to the scalp, outwards extends to the outer corner of the eyes, the fronto-nasal canal opens in the anterior part of the middle nasal passage. The frontal sinus may be absent. It is often asymmetrical, being larger on one side. In a newborn, it already exists in the form of a small bay, which increases every year, but their underdevelopment or incomplete absence (aplasia) of the frontal sinus occurs.

The main (sphenoid, sphenoidal) sinus is located in the body of the sphenoid bone. Its shape resembles an irregular cube. Its value varies greatly. It borders on the middle and anterior cranial fossae, with its bony walls adjacent to the cerebral appendage (pituitary gland) and other important formations (nerves, blood vessels). The opening leading to the nose is located on its front wall. The main sinus is asymmetric: in most cases, the septum divides it into 2 unequal cavities.

The lattice labyrinth has a bizarre structure. The cells of the ethmoid labyrinth are wedged between the frontal and sphenoid sinuses. Outside, the lattice labyrinth borders on the orbit, from which it is separated by the so-called paper plate; from the inside - with the upper and middle nasal passages; above - with the cavity of the skull. The size of the cells is very different: from a small pea to 1 cm 3 or more, the shape is also varied.

The cells are divided into anterior and posterior, the first of which open in the middle nasal passage. The posterior cells open in the superior nasal passage.

The ethmoidal labyrinth is bordered by the orbit, the cranial cavity, the lacrimal sac, the optic nerve, and other ophthalmic nerves.

The nose is the initial part of the upper respiratory tract and is divided into three sections:
- External nose.
- Nasal cavity.
- Paranasal sinuses.

External nose
The external nose is a bone-cartilaginous pyramid covered with skin. The following elements of the external nose are distinguished: root, back, slopes, wings and tip. Its walls are formed by the following tissues: bone, cartilage and skin.

1. The bone part of the skeleton consists of the following elements:
paired nasal bones;
frontal processes of the upper jaw;
nasal process of the frontal bone.
2. Cartilages of the external nose are paired:
triangular;
wing;
additional.
3. The skin covering the nose has the following features:
an abundance of sebaceous glands, mainly in the lower third of the external nose;
a large number of hairs on the eve of the nose, performing a protective function;
an abundance of blood vessels that anastomose with each other.

The basis of the cartilaginous section of the external nose is the lateral cartilage, the upper edge of which borders on the nasal bone of the same side and partially on the frontal process of the upper jaw. The upper faces of the lateral cartilages constitute a continuation of the back of the nose, adjoining in this section to the cartilaginous part of the upper parts of the nasal septum. The lower face of the lateral cartilage borders on the large cartilage of the wing, which is also paired. The large cartilage of the wing has a medial and lateral crura. Connecting in the middle, the medial legs form the tip of the nose, and the lower sections of the lateral legs are the edge of the nasal openings (nostrils). Sesamoid cartilages of various shapes and sizes can be located between the lateral and large cartilages of the wing of the nose in the thickness of the connective tissue.

The alar of the nose, in addition to the large cartilage, includes connective tissue formations, from which the posterior inferior sections of the nasal openings are formed. The inner sections of the nostrils are formed by the movable part of the nasal septum.

The outer nose is covered with the same skin as the face. The external nose has muscles that are designed to compress the nasal openings and pull down the wings of the nose:
1. Alar dilator
2. Transverse muscle
3. Superficial levator of the wings of the nose
4. True alar dilator
5. Nasal septal depressor

The nasal valve is a slit-like formation between the caudal end of the superior lateral cartilage at its attachment to the nasal septum and the nasal septum itself. The valve is necessary to ensure normal (turbulent) air flow into the nasal cavity. The angle between the cartilage and the septum is called the nasal valve angle. In people of the white race, it is 10-15 degrees.

1. Facial artery

2. Superior labial artery

3. Angular artery

4. Alar artery of the nose

5. Columellar or infraseptal artery

6. Artery of the back of the nose

7. Arcades of the back of the nose

The blood supply to the external nose is provided from the system of external and internal carotid arteries. Venous outflow is carried out through the facial, angular and partially ophthalmic veins into the cavernous sinus, which in some cases contributes to the spread of infection in inflammatory diseases of the external nose to the sinuses of the dura mater. Lymphatic drainage from the external nose occurs in the submandibular and upper parotid lymph nodes. The motor innervation of the external nose is provided by the facial nerve, the sensory innervation is provided by the trigeminal (I and II branches).

Anatomy of the nasal cavity

The anatomy of the nasal cavity is more complex. The nasal cavity is located between:
- anterior cranial fossa (top)
- eye sockets (laterally)
- oral cavity (bottom)

The nasal cavity is divided by a septum into right and left halves and has anterior openings - nostrils and posterior - choanae leading to the nasopharynx.
Each half of the nose has four walls.

The medial wall, or nasal septum, is formed by:
quadrangular cartilage in the anterior section;
perpendicular plate of the ethmoid bone in the upper section;
opener in the lower back section;
nasal crest of the palatine process of the upper jaw;
In the anterior sections, a quadrangular cartilage of the nasal septum adjoins these bone formations;
In the anteroinferior section, the cartilage of the nasal septum adjoins the medial crura of the lower lateral cartilage of the alar of the nose, which, together with the skin part of the nasal septum, constitute its movable part;
The upper wall (roof) in the anterior sections is formed by:
nasal bones, frontal processes of the upper jaw, partially perpendicular plate of the ethmoid bone;
in the middle sections:
ethmoid (perforated) plate of the ethmoid bone;
in the back sections:
sphenoid bone (anterior wall of the sphenoid sinus);
The cribriform plate is pierced by a large number (25-30) holes through which the branches of the anterior ethmoidal nerve and the vein that accompanies the anterior ethmoid artery and connects the nasal cavity with the anterior cranial fossa pass.
The lower wall, or bottom of the nasal cavity, is formed by:
alveolar process of the upper jaw (in the anterior sections);
palatine process of the upper jaw;
horizontal plate of the palatine bone.
At the anterior end of the bottom of the nose there is a canal that serves to pass the nasopalatine nerve from the nasal cavity to the oral cavity.
The lateral wall, which has the greatest clinical significance, is the most complex in structure. It is formed by the following bones:
frontal process of the maxilla, lacrimal bone (in the anterior section);
ethmoid labyrinth of the ethmoid bone, inferior nasal concha (in the middle section);
vertical plate of the palatine bone, pterygoid process of the sphenoid bone (in the posterior region);
On the inner surface of the lateral wall there are three bony protrusions - nasal conchas. The superior and middle turbinates are processes of the ethmoid bone, while the inferior is an independent bone. Under the shells are the corresponding nasal passages - upper, middle and lower. The space between the nasal septum and the edges of the turbinates forms a common nasal passage. In young children, the inferior turbinate closely adheres to the bottom of the nasal cavity, which leads to a complete shutdown of nasal breathing even with slight inflammation of the mucosa.

The most important structures of the lateral wall are the turbinates.
These are bone structures covered with a mucous membrane, emanating from the lateral wall. Usually there are three, rarely four. The superior, middle, and inferior turbinates can usually be seen in any individual. However, sometimes there is a fourth shell - concha nasalis suprema.
The air spaces below and lateral to the shells are called:
- superior nasal passage
- Middle nasal passage
- lower nasal passage

The outlet of the nasolacrimal canal opens into the lower nasal passage, a delay in its opening leads to disruption of the outflow of tears, cystic dilation of the canal and narrowing of the nasal passages in newborns;
The maxillary sinus opens into the middle nasal passage, in the anterior upper section - the canal of the frontal sinus, in the middle part of the passage - the anterior and middle cells of the ethmoid bone;
In the middle nasal passage, there is an osteomeatal complex that provides ventilation for the ethmoid, maxillary, frontal sinuses and receives mucus from them. It consists of:
- uncinate process
- anterior squamous cells (vesicles)
- funnel (medial wall - uncinate process, lateral - nasal septum)
- opening of the maxillary sinus (located in the anterior lower part of the infundibulum)
- lateral surface of the middle turbinate
The sphenoid sinus and the posterior cells of the ethmoid labyrinth open into the upper nasal passage.

The blood supply to the nasal cavity is carried out from the system of external (a. carotis externa) and internal (a. carotis interim) carotid arteries. The main palatine artery (a. sphenopalatina) originates from the first artery; passing through the main palatine opening (foramen sphenopalatinum) into the nasal cavity, it gives off two branches - the posterior nasal lateral and septal arteries (aa. nasales posteriores laterales et septi), which provide blood supply to the posterior sections of the nasal cavity, both lateral and medial walls. The ophthalmic artery originates from the internal carotid artery, from which the branches of the anterior and posterior ethmoidal arteries (aa. ethmoidales anterior et posterior) depart. The anterior ethmoidal arteries pass into the nose through the cribriform plate, the posterior ones through the posterior ethmoidal foramen (foramen ethmoidale post.). They provide nutrition to the area of ​​the ethmoidal labyrinth and the anterior parts of the nasal cavity.
The outflow of blood is carried out through the anterior facial and ophthalmic veins. Features of the outflow of blood often cause the development of ophthalmic and intracranial rhinogenic complications. In the nasal cavity, especially pronounced venous plexuses are found in the anterior sections of the nasal septum.
Lymphatic vessels form two networks - superficial and deep. The olfactory and respiratory regions, despite their relative independence, have anastomoses. Lymph outflow occurs in the same lymph nodes: from the anterior parts of the nose to the submandibular, from the posterior to the deep cervical.

Blood supply to the nasal septum

blood supply to the lateral wall

Sensitive innervation of the nasal cavity is provided by the first and second branches of the trigeminal nerve. The anterior part of the nasal cavity is innervated by the first branch of the trigeminal nerve (anterior ethmoid nerve - n. ethmoidalis anterior-branch of the nasociliary nerve - n. nasociliaris). The nasociliary nerve from the nasal cavity penetrates through the nasociliary foramen (foramen nasociliaris) into the cranial cavity, and from there through the cribriform plate into the nasal cavity, where it branches in the region of the nasal septum and the anterior sections of the lateral wall of the nose. The external nasal branch (ramus nasalis ext.) between the nasal bone and the lateral cartilage extends to the back of the nose, innervating the skin of the external nose.
The posterior parts of the nasal cavity are innervated by the second branch of the trigeminal nerve, which enters the nasal cavity through the posterior ethmoid foramen and branches in the mucous membrane of the posterior cells of the ethmoid bone and the sinus of the sphenoid bone. The nodal branches and the infraorbital nerve depart from the second branch of the trigeminal nerve. The nodal branches are part of the pterygopalatine node, however, most of them pass directly into the nasal cavity and innervates the posterior superior part of the lateral wall of the nasal cavity in the region of the middle and superior turbinates, the posterior cells of the ethmoid bone and the sinus of the sphenoid bone in the form of rr. nasales.
Along the nasal septum in the direction from back to front there is a large branch - the nasopalatine nerve (n. Nasopalatinus). In the anterior parts of the nose, it penetrates through the incisive canal into the mucous membrane of the hard palate, where it anastomoses with the nasal branches of the alveolar and palatine nerves.
Secretory and vascular innervation is carried out from the superior cervical sympathetic ganglion, the postganglionic fibers of which penetrate the nasal cavity as part of the second branch of the trigeminal nerve; parasympathetic innervation is carried out through the pterygopalatine ganglion (gang. pterigopalatinum) due to the nerve of the pterygoid canal. The latter is formed by a sympathetic nerve extending from the superior cervical sympathetic ganglion and a parasympathetic nerve originating from the geniculate ganglion of the facial nerve.
Specific olfactory innervation is carried out by the olfactory nerve (n. olfactorius). Sensory bipolar cells of the olfactory nerve (I neuron) are located in the olfactory region of the nasal cavity. The olfactory filaments (filae olfactoriae) extending from these cells penetrate the cranial cavity through the cribriform plate, where, when combined, they form an olfactory bulb (bulbus olfactorius), enclosed in a vagina formed by the dura mater. The pulpy fibers of the sensory cells of the olfactory bulb form the olfactory tract (tractus olfactorius - II neuron). Further, the olfactory pathways go to the olfactory triangle and end in the cortical centers (gyrus hippocampi, gyrus dentatus, sulcus olfactorius).

Clinical anatomy of the paranasal sinuses
The paranasal sinuses are air cavities located around the nasal cavity and communicating with it through excretory openings or ducts.
There are four pairs of sinuses:
maxillary, frontal, ethmoid labyrinth and wedge-shaped (basic).
The clinic distinguishes between the anterior sinuses (maxillary, frontal and anterior and middle ethmoid) and posterior (posterior ethmoid cells and sphenoid). Such a subdivision is convenient from a diagnostic standpoint, since the anterior sinuses open into the middle nasal passage, and the posterior sinuses open into the upper nasal passage.
The maxillary sinus, (aka maxillary sinus) located in the body of the maxillary bone, is an irregularly shaped pyramid ranging in size from 15 to 20 cm3.
The anterior or facial wall of the sinus has a depression called the canine fossa. In this area, the sinus is usually opened. Immediately below it, the infraorbital nerve emerges. In the region of the canine fossa, the wall is the thinnest.
The medial wall is the lateral wall of the nasal cavity and contains a natural outlet in the region of the middle nasal passage. It is located almost under the roof of the sinus, which makes it difficult for the outflow of contents and contributes to the development of congestive inflammatory processes.
The upper wall of the sinus simultaneously represents the lower wall of the orbit. It is quite thin, often has bone clefts, which contributes to the development of intraorbital complications. In it pass the canal of the infraorbital nerve and the vessels of the same name.
The lower wall is formed by the alveolar process of the maxilla and usually occupies the space from the second premolar to the second molar. The low position of the bottom of the sinus contributes to the proximity of the roots of the teeth to the sinus cavity. In some cases, the tops of the roots of the teeth stand in the lumen of the sinus and are only covered by the mucous membrane, which can contribute to the development of odontogenic infection of the sinus, the ingress of filling material into the sinus cavity, or the formation of a persistent perforation during tooth extraction.
The posterior wall of the sinus is thick, borders on the cells of the ethmoid labyrinth and the sphenoid sinus, and encloses the pterygopalatine fossa in front.
The frontal sinus is located in the thickness of the frontal bone and has four walls:
lower (orbital) - the thinnest, which is the upper wall of the orbit, borders on the cells of the ethmoid bone and the nasal cavity
anterior - the thickest up to 5-8 mm,
posterior (brain), separating the sinus from the anterior cranial fossa,
internal (medial, interaxillary) septum.
The front and back walls converge at an angle.
The frontal sinus communicates with the nasal cavity through a thin tortuous frontonasal canal that opens into the anterior semilunar fissure of the middle nasal passage. The size of the sinus ranges from 3 to 5 cm3, and in 10-15% of cases it may be absent.
The sphenoid, or main, sinus is located in the body of the sphenoid bone, divided by a septum into two halves, which have an independent exit to the region of the upper nasal passage through a sphenoid opening in the anterior wall.
Has the following walls:
Internal - intersinus septum, divides the sinus into 2 halves, continues anteriorly to the nasal septum.
The outer one is thin, the internal carotid artery, the cavernous sinus border it, the oculomotor, 1 pair of trigeminal, trochlear and abducens nerves pass here.
Anterior - through the sphenoid opening it communicates with the upper nasal passage.
The posterior is the thickest and passes into the basilar region of the occipital bone.
Lower - partially represents the vault of the nasopharynx.
Upper - the lower surface of the Turkish saddle, the pituitary gland, the frontal lobe of the brain with olfactory convolutions is adjacent to it.
Near the sphenoid sinus are the cavernous sinus, carotid artery, optic chiasm, pituitary gland. As a result, the inflammatory process of the sphenoid sinus is a serious danger.
The ethmoid sinuses (ethmoid labyrinth) is located between the orbit and the nasal cavity, the frontal and sphenoid sinuses and consists of 5-20 air cells, each of which has its own outlet openings into the nasal cavity. There are three groups of cells: anterior and middle, opening into the middle nasal passage, and posterior, opening into the upper nasal passage. Outside, they border on the paper plate of the orbit, the medial wall of the ethmoid bone enters the lateral wall of the nasal cavity. The blood supply to the paranasal sinuses occurs due to the branches of the external and internal carotid arteries. The veins of the maxillary sinus form numerous anastomoses with the veins of the orbit, nose, sinuses of the dura mater.
Lymphatic vessels are closely connected with the vessels of the nasal cavity, vessels of the teeth, retropharyngeal and deep cervical lymph nodes.
Innervation is carried out by the first and second branches of the trigeminal nerve.

Russia: weather and your health on 25.01.2008

id="0">In the north, northwest and in the center of the European territory of Russia, the main adverse factor will be a significant decrease in atmospheric pressure. In this regard, people with chronic fatigue syndrome, as well as those suffering from cardiovascular diseases, primarily hypertension, atherosclerosis of the cerebral vessels, will feel uncomfortable.

Plus, high humidity and temperatures that are still above normal will form damp, but warm, weather. This type of weather is primarily unfavorable for people suffering from various respiratory diseases, as well as broncho-pulmonary diseases, asthma, and various dermatitis. Such weather contributes to the spread of acute respiratory diseases. Experts recommend that people who are prone to spastic reactions stock up on the necessary medications and try to spend more time in the air in order to avoid oxygen deficiency. When going out, we recommend dressing appropriately for the weather. In the Urals, in the south of Western Siberia, in the Krasnoyarsk Territory, in Transbaikalia, Irkutsk, Amur Regions, in Yakutia, in the Khabarovsk Territory, high atmospheric pressure and low air temperature will remain. Such weather conditions continue to support spasmodic weather. Persons prone to spastic reactions should stock up on the necessary medicines, especially in the early morning hours when leaving a warm room outside. In the Kuril Islands and in the south of Sakhalin, a strong gusty wind will become an unfavorable weather phenomenon, which can cause a feeling of anxiety and anxiety in people with psycho-emotional disorders. The geomagnetic background on January 25 is predicted to be calm.

In Moscow, the number of people with influenza and SARS has noticeably increased, but the incidence remains significantly below the epidemic level

id="1">In the capital over the past week, the number of people with influenza and SARS has increased by more than 30 percent. This was announced today by the territorial department of Rospotrebnadzor for the city of Moscow.

In the period from January 14 to January 20, the increase in the number of cases was 31.8 percent. A total of 56 thousand 160 people fell ill, of which 28 thousand 966 were children. The department clarified that the incidence rates in the city as a whole among adults and children are 40.6 percent lower than the estimated epidemic level, in particular, the proportion of influenza, according to clinical diagnoses, was 0.3 percent.

After the New Year holidays, the head of the Federal Service for Supervision of Consumer Rights Protection and Human Welfare, Gennady Onishchenko, said that an epidemic of influenza and acute respiratory infections was not expected in Russia. He noted that "influenza and colds will not go beyond the usual, a super surge is not expected." Onishchenko said that 21.5 million people have been vaccinated against influenza in Russia, which is just over 94 percent of the plan as part of the national Health project. To vaccinate the population of the country, the state purchased 25.4 million doses of the vaccine.

The message of Rospotrebnadzor of the Russian Federation, which was received today, also states that there is no flu epidemic in Russia. "In the country as a whole, the incidence of influenza and SARS is currently regarded as non-epidemic," the ministry said.

The state will provide future employees of high-tech medical centers with internships in the best domestic and foreign clinics

id="2"> According to RIA Novosti, this was stated by First Deputy Prime Minister Dmitry Medvedev during a meeting held yesterday at the Center for Cardiovascular Surgery in Penza, in which he participated together with Vladimir Putin.

“The personnel component is very important, it is very important that personnel training and retraining of personnel for these centers take place. We will have to provide internships in the best foreign and domestic clinics for all the specialists who work there,” Medvedev said.

The First Vice Prime Minister also noted the importance of using "new organizational and legal forms" to pay doctors.

“We did the right thing when we made the decision to build such centers,” Vladimir Putin said opening the meeting in Penza. The President added that the emergence of new high-level medical centers will help improve the overall level of healthcare in the regions.

In addition, Putin proposed holding a special meeting on the development of the production of domestic medical equipment and medicines. He expressed his confidence. That for some types of medical equipment, Russia will be able to reach the world level and confidently compete with Western manufacturers in the near future.

The decree on the creation of the Federal Agency for High-Technological Medical Care was signed by Putin on July 4, 2006. The decree provides for the creation of a wide network of high-tech medical centers in the regions of Russia. The first fourteen such centers are planned to be put into operation this year.

Stress in the workplace increases the risk of developing coronary artery disease "caused by direct neuroendocrine activation"

id="3">British researchers have shown that workplace stress increases the risk of developing coronary artery disease due to direct activation of neuroendocrine stress, as well as due to an irrational lifestyle.

Tarani Chandola (University College London) and co-authors analyzed the results of observation of 10,000 London employees over 20 years.

The study involved 10,308 men and women aged 35-55 years. Workplace stress was assessed using a self-administered questionnaire.

Higher levels of stress in the workplace are associated with a greater risk of coronary artery disease. Also, a high level of stress was associated with an irrational lifestyle. For example, stressed workers ate vegetables and fruits less frequently, were less physically active, and did not consume alcohol, with odds ratios of 2.12, 1.33, and 1.42, respectively, compared. They were also more likely to develop metabolic syndrome (1.33).

In addition, workers with high levels of stress had higher levels of cortisol in the morning.
Circulation 2008; Advance online publication.

'Telepathic connection' between DNA molecules discovered

id="4">DNA with a similar structure is able to recognize each other without the help of proteins and other biochemical compounds. These are the conclusions of the authors of a study published in the Journal of Physical Chemistry. According to the scientists, the mechanism they discovered provides for the homologous recombination of DNA, which plays an important role in the evolution of biological species.

The universal carrier of hereditary information, the DNA molecule, includes two chains of purine and pyrimidine bases that encode the sequence of amino acids in proteins. Non-sex cells of most living organisms have a double set of DNA, consisting of paired molecules with a similar (homologous) structure.

Employees of the Imperial College London, led by Russian scientist Professor Alexei Kornyshev, studied the behavior of DNA molecules in a solution purified from other organic compounds. As it turned out, DNA chains approached and interacted with each other, and these interactions were observed twice as often between homologous molecules. It was previously believed that selective interactions between homologous DNA molecules are possible only with the participation of proteins and other chemical compounds.

The mechanism of the "telepathic" connection between DNA has not yet been explained, but scientists suggest that these large molecules can "recognize" each other by the distribution of electrical charges. Moreover, the probability of such recognition increases as the length of DNA chains increases.

According to the researchers, the mechanism of interaction described by them is used in homologous recombination - the exchange of genes between similar DNA molecules. This process provides a variety of genetic combinations within a species, it is also important for maintaining the normal structure of DNA in the event of accidental damage. The idea of ​​the basic mechanism of homologous recombination will allow scientists to better understand the natural mechanisms of protection against mutations and improve the methods of genetic engineering and gene therapy.

Organ rejection can be avoided without the help of immunosuppressants

id="5">Two independent teams of American scientists say they have been able to save kidney transplant patients from lifelong immunosuppressive drugs. A report of these cases was published in the New England Journal of Medicine.

The experiments, conducted by scientists from the Massachusetts Hospital and Harvard Medical School, involved five people who needed a kidney transplant. Scientists destroyed part of the patients' bone marrow and, with the help of drugs, destroyed immune cells that play a key role in rejecting a foreign organ. The participants were then transplanted with bone marrow and a kidney taken from the same donor.

Two to five years after transplantation, four patients have a normally functioning kidney and do not require immunosuppressive drugs.

In turn, specialists from the Stanford University School of Medicine, led by John Scandling, have succeeded in the case of 47-year-old Larry Kowalski, who received a kidney transplant from his brother. The bodies of men were perfectly compatible. To minimize the risk of kidney rejection, the scientists manipulated the patient's immune system by irradiating and injecting antibodies. In addition, he was transfused with regulatory T cells from his brother's blood, which act as "peacekeepers" of the immune system and prevent the rejection of a foreign organ.

The first time after the kidney transplantation, Kowalski had to take immunosuppressive drugs, but six months later they were completely canceled. 34 months after giving up medication, the man feels great, rides a bike, snowboards and dives, regularly visits the gym and is raising a three-year-old son.

Lifelong use of immunosuppressive drugs, which patients need after a donor organ transplant, has many side effects. Medicines increase the risk of infectious complications, hypertension, high cholesterol levels, and also contribute to the development of certain types of cancer. Refusal to take immunosuppressive drugs can significantly improve the quality of life of patients, but more research is needed on the safety of new methods, scientists believe.

Shout at your spouse "health"

id="6">Heavy showdowns with a spouse improve health, and the desire to restrain shortens life, according to the results of a scientific study.

Researchers at the University of Michigan Institute of Public Health have published preliminary results from studies they conducted on 192 couples over a period of 17 years.

All study participants were divided into four groups: couples in which both spouses reacted violently to any, in their opinion, undeserved insult; couples where spouses held back emotions; as well as two groups in which anger was expressed either only by the spouse, or only by the spouse.

Project leader Ernest Harburg says it's bad for your health to endure resentment and keep silent.

"If you do not express your feelings to your partner and do not tell him what offended you, this may end badly for you"
Ernest Harburg. Project Manager.

"If you do not express your feelings to your partner and do not tell him what hurt you, it may end badly for you," he says.

The study found that spouses who don't let their anger out are twice as likely to die prematurely as those who don't.

Of the 26 couples in which both spouses endured grievances in silence, 13 people died during the study period, while out of 166 other couples, only 41 people died.

"In family life, it is very important to be able to resolve conflicts," says Ernest Harburg.

"This is not taught anywhere at all. It's good if you had wise parents and you could learn this important experience from them. But usually married couples have no idea how to "repay" the conflict," he adds.

According to the scientist, resentment is very dangerous, and by suppressing anger, spouses only drive resentment inward and accumulate them.

Harburg explains that resentment exacerbates the "weakness" in a particular organ or body system and increases the risk of their disease.

“It is quite normal to feel that you are offended, and do not be shy to speak out about this. In this way, you will solve the problem and prolong your life,” says Ernest Harburg.

Cavum nasi, is a space that lies in the sagittal direction from the pyriform aperture to the choanae and is divided into two halves by a septum. The nasal cavity is bounded by five walls: superior, inferior, lateral and medial.
Top wall formed by the frontal bone, the inner surface of the nasal bones, the lamina cribrosa of the ethmoid bone and the body of the sphenoid bone.
bottom wall formed by the bony palate, palatinum osseum, which includes the palatine process of the upper jaw and the horizontal plate of the palatine bone.
Lateral wall formed by the body of the maxilla, the nasal bone, the frontal process of the maxilla, the lacrimal bone, the labyrinth of the ethmoid bone, the inferior nasal concha, the perpendicular plate of the palatine bone and the medial plate of the pterygoid process.
medial wall, or nasal septum, septum nasi osseum, divides the nasal cavity into two halves. It is formed by a perpendicular plate of the ethmoid bone and a plowshare, from above - by the nasal spine of the frontal bone, spina nasalis, from behind - by the sphenoid crest, crista sphenoidalis, sphenoid bone, from below - by the nasal crest, crista nasales, upper jaw and palatine bone. The nasal cavity opens in front with a pear-shaped aperture, apertura piriformis, and behind with choanae. Choanae, choanae - paired internal openings of the nasal cavity that connect it to the nasal part of the pharynx.
On the lateral wall of the nasal cavity there are three nasal conchas: upper, middle and lower, concha nasalis superior, media et inferior. The upper and middle turbinates belong to the labyrinth of the ethmoid bone, the lower one is an independent bone. The listed shells limit three nasal passages: upper, middle and lower, meatus nasalis superior, medius et inferior.
superior nasal passage, meatus nasalis superior, lies between the upper and middle nasal conchas. The posterior cells of the ethmoid bone open into it. At the posterior end of the superior turbinate there is a cuneiform opening, foramen sphenopalatinum, leading to the fossa pterygopalatina, and above the superior turbinate there is a wedge-shaped depression, recessus spheno-ethmoidalis, in the region of which the sphenoid sinus, sinus sphenoidalis, opens.
middle nasal passage, meatus nasalis medius, located between the middle and lower nasal conchas. Within its limits, after the removal of the middle shell, a semilunar opening, hiatus semilunaris, opens. The posterior part of the semilunar foramen expands, at the bottom of which there is a hole, hiatus maxillaris, leading to the maxillary sinus, sinus maxillaris. In the anterior-upper part of the nasal cavity, the semilunar opening expands and forms a cribriform funnel, infundibulum ethmoidale, into which the frontal sinus, sinus frontalis, opens. In addition, the anterior and some middle ethmoidal cells open into the middle nasal passage and semilunar opening.
inferior nasal passage, meatus nasalis inferior, located between the bony palate and the inferior nasal concha. It opens the nasolacrimal canal, canalis nasolacrimal. In clinical (otolaryngological) practice, the maxillary sinus is punctured through the lower nasal passage for diagnostic and therapeutic purposes.
The slit-like space between the posterior turbinates and the bony nasal septum is called the common nasal passage, meatus nasi communis. The section of the nasal cavity, located behind the nasal conchas and the bony nasal septum, forms the nasopharyngeal passage, meatus nasopharyngeus, which opens into the posterior nasal openings - the choanae.
buttresses- these are bone thickenings in separate parts of the skull, combined with each other by transverse shifts, through which, during chewing, the pressure force is transmitted to the cranial vault. Buttresses balance the force of pressure that occurs during chewing, pushing and jumping. Between these thickenings are thin bone formations called weak spots. It is here that fractures most often occur during physical exertion, which does not coincide with the physiological acts of chewing, swallowing and speech. In clinical practice, fractures are more often observed in the region of the neck of the lower jaw, angle and upper jaw, as well as the zygomatic bone and its arch. The presence of holes, fissures and weaknesses in the bones of the skull determine the direction of these fractures, which is important to consider in maxillofacial surgery. In the upper jaw, the following buttresses are distinguished: fronto-nasal, collar-zygomatic, palatine and pterygopalatine; at the bottom - cellular and ascending.

The nose is an important part of the human body. It has a rather complicated structure and performs many functions, providing free breathing and. From the point of view of clinical anatomy, the nose is usually divided into external and internal parts.

Structure of the external nose

The nose consists of outer and inner parts.

Outside, the nose is covered with skin, which contains many sebaceous glands. This section of the nose consists of cartilage and bone tissue and is shaped like a trihedral pyramid. Its upper part is usually called the root of the nose, which, lengthening downwards, passes into the back and ends at the top. The wings of the nose are located on the sides of the back, they are mobile structures and form the entrance to the nasal cavity.

The bone skeleton of the nose consists of thin and flat nasal bones, they are connected to each other (along the midline), as well as to other structures of the facial skeleton. Its cartilaginous part is represented by paired lateral cartilaginous plates located above and below.

This section of the nose is abundantly supplied with blood by branches of the external carotid artery. Certain features have an outflow of venous blood from this area, which is carried out into the anterior facial vein, which communicates with the ophthalmic vein and the cavernous sinus. This structure is due to the possibility of rapid spread of pathogens of infectious diseases with blood flow into the cranial cavity.

The inside of the nose

The nasal cavity is located between the oral cavity, orbits and anterior cranial fossa. It communicates with the environment (through the nostrils) and the pharynx (through the choanae).

The lower wall of the nasal cavity is formed by the palatine bones and processes of the same name of the upper jaw. In the depths of this wall, closer anteriorly, is the incisive canal, in which nerves and blood vessels pass.

The roof of the internal nose is formed by the following bone structures:

• cribriform plate of the same name bone;
• nasal bones;
• anterior wall of the sphenoid sinus.

Olfactory nerve fibers and arteries penetrate here through the cribriform plate.

The nasal septum divides its cavity into two parts - cartilage and bone:

• The latter is represented by the vomer, the perpendicular plate of the ethmoid bone and the nasal crest of the upper jaw.
• The cartilaginous part is formed by the own cartilage of the nasal septum, which has the shape of a quadrangle, which participates in the formation of the back of the nose and is part of the movable section of the septum.

The most difficult is the lateral wall of the nasal cavity. It is formed by several bones:

• lattice,
• palatine,
• wedge-shaped
• lacrimal bone,
• upper jaw.

It has special horizontal plates - the upper, middle and lower nasal concha, which conditionally divide the inner part of the nose into 3 nasal passages.

1. Lower (located between the nasal concha of the same name and the bottom of the nasal cavity; the nasolacrimal canal opens here).
2. Medium (limited by two nasal conchas - lower and middle; has fistulas with all paranasal sinuses, except for the sphenoid).
3. Upper (located between the arch of the nasal cavity and the superior nasal concha; the sphenoid sinus and the posterior cells of the ethmoid bone communicate with it).

In clinical practice, a common nasal passage is distinguished. It looks like a slit-like space between the septum and nasal conchas.

All departments of the inner part of the nose, except for the vestibule, are lined with a mucous membrane. Depending on its structure and functional purpose, the respiratory and olfactory zones are distinguished in the nasal cavity. The latter is located above the lower edge of the middle turbinate. In this part of the nose, the mucous membrane contains a large number of olfactory cells, which are able to distinguish more than 200 odors.

The respiratory region of the nose is below the olfactory region. Here the mucous membrane has a different structure, it is covered with multinucleated ciliated epithelium with many cilia, which in the anterior parts of the nose make oscillatory movements towards the vestibule, and in the posterior parts, on the contrary, towards the nasopharynx. In addition, this zone contains goblet cells that produce mucus and tubular alveolar glands that produce serous secretions.

The medial surface of the lower part of the middle turbinate has a thickened mucous membrane due to the cavernous tissue, which contains a large number of venous dilatations. It is with this that its ability to quickly swell or contract under the influence of certain stimuli is connected.

The blood supply to the intranasal structures is carried out by vessels from the carotid artery system, both from its external and internal branches. That is why with massive ones it is not enough to bandage one of them to stop it.

A feature of the blood supply to the nasal septum is the presence in its anterior part of a weak spot with a thinned mucosa and a dense vascular network. This is the so-called Kisselbach zone. There is an increased risk of bleeding in this area.

The venous network of the nasal cavity forms several plexuses in it, it is very dense and has numerous anastomoses. The outflow of blood goes in several directions. This is due to the high risk of developing intracranial complications in diseases of the nose.

The innervation of the nose is carried out by the olfactory and trigeminal nerves. The latter is associated with the possible irradiation of pain from the nose along its branches (for example, to the lower jaw).

In addition, sufficient functioning of the nose is necessary for normal blood gas exchange. Chronic nasal diseases with or narrowing of the respiratory space lead to insufficient oxygen supply to the tissues and disruption of the nervous system.

Prolonged difficulty in nasal breathing in childhood contributes to a delay in mental and physical development, as well as the development of deformation of the facial skeleton (change in bite, high "Gothic" sky,).

Let us dwell in more detail on the main functions of the human nose.

1. Respiratory (regulates the speed and volume of air entering the lungs; due to the presence of reflexogenic zones in the nasal cavity, it provides wide connections with various organs and systems).
2. Protective (warms and humidifies the inhaled air; the constant flicker of the cilia cleanses it, and the bactericidal action of lysozyme helps prevent pathogens from entering the body).
3. Olfactory (the ability to distinguish odors protects the body from the harmful effects of the environment).
4. Resonator (together with other air cavities, it participates in the formation of an individual voice timbre, provides a clear pronunciation of some consonant sounds).
5. Participation in lacrimal excretion.

Conclusion

Changes in the structure of the nose (developmental anomalies, curvature of the nasal septum, etc.) inevitably lead to disruption of its normal functioning and the development of various pathological conditions.