What Is the Nasal Cavity?

It is a long and narrow cavity with a narrow bottom and a wide front. The same nasal septum is divided into left and right cavities, and each side of the nasal cavity includes the nasal vestibule and the inherent nasal cavity. The nasal cavity is divided into left and right by a longitudinal nasal septum. The nasal septum is often biased to one side due to its position, so the size and shape of the left and right nasal cavities are mostly asymmetric.

It is a long and narrow cavity with a narrow bottom and a wide front. It starts from the front nostril and ends at the back nostril, communicating with the nasopharynx. The same nasal septum is divided into left and right cavities, and each side of the nasal cavity includes the nasal vestibule and the inherent nasal cavity. The nasal cavity is divided into left and right by a longitudinal nasal septum. The nasal septum is often biased to one side due to its position, so the size and shape of the left and right nasal cavities are mostly asymmetric.

Chinese name

nasal cavity

Foreign name

nasal cavity

Hanyu Pinyin

bíqing

Classification

Human organs

Organization structure

Nasal vestibule, mucosa, blood vessels, lymph, nerve

Location

Human head

Nasal Overview

The nasal cavity communicates with the outside world through the nostril, and the nasopharynx is called the nostril. Each side of the nasal cavity is divided into two parts: the nasal vestibule and the inherent nasal cavity. There is nasal hair in the nasal cavity, which can filter the inhaled air and reduce the inhalation of harmful substances such as dust. There are olfactory cells and secretory glands in the nasal mucosa, as well as quite rich capillaries. Therefore, the nasal cavity can warm and humidify the inhaled gas.

Nasal cavity anatomical structure:

The nasal cavity is composed of bone and cartilage and their surface-covered mucosa and skin. It is located between the skull base and the oral cavity, and is connected to the sinuses. The nasal cavity is divided into left and right sides by a nasal septum. The vestibule and the inherent nasal cavity, the anterior nasal vestibule leads to the anterior nostril, and the posterior nasal cavity connects the nasopharynx.

Each side of the nasal cavity has a top, bottom, medial wall, and lateral wall.

(A) the top wall

Domed. The anterior segment is obliquely rising, consisting of the nasal bone and the frontal nasal process; the posterior segment is obliquely downward, that is, the anterior wall of the sphenoid sinus; the middle segment is the horizontal ethmoid plate that separates the anterior skull base. Named sieve plate, the olfactory filaments that hold the mucosa of the olfactory region enter the skull through the sieve hole. The mucosa of the olfactory area is distributed in the middle of the top of the nasal cavity, down to the upper part of the nasal septum and the upper part of the outer wall of the nasal cavity. The sieve plate is thin and fragile, and it is easy to be injured when trauma such as anterior skull base fracture or nasal surgery is performed on the site; anterior skull base meningiomas can sometimes damage the sieve plate and enter the nasal cavity; Intracranial.

(B) the bottom wall

That is, the nasal surface of the hard palate is separated from the oral cavity. The front 3/4 is composed of the maxillary condyle and the rear 1/4 is composed of the horizontal part of the jawbone.

(Three) the inner wall

The nasal septum. It consists of osseous and cartilageous nasal septum. The anterior upper part is the vertical ethmoid plate, the posterior lower part is vomera, and the anterior lower part is nasal septal cartilage. The two sides of the nasal septum are covered with mucosa, and the corresponding part of the middle turbinate is thick. The mucosa contains a large number of glands and blood vessels. The nasal septum is often on one side, and its anterior and inferior blood vessels are rich and superficial. Traumatic or dry irritation can easily cause bleeding; 90% of nasal bleeding occurs in this area, so it is said that the bleeding area is Little or Kiesselbach. Therefore, the position of the septal mucosa during transsphenoidal surgery should be as far as possible in the posterior part of the nasal septum, that is, at the junction of the nasal septum cartilage and the bone or at the rear of the septum, to avoid incision in the Little area and cause more bleeding.

(Four) outer wall

It consists of maxilla, lacrimal bone, turbinate, ethmoid labyrinth, vertical plate of jawbone, and sphenoid wing process. From the bottom of the nasal cavity, there are three long bone pieces arranged in a stepwise manner from the bottom to the middle, and the upper turbinates are reduced in size by 1/3, and the position of the front end is shifted by about 1/3 in turn. A gap is formed below the turbinate and the outer wall of the nasal cavity, which is called the lower, middle and upper nasal passages. The nasal passage between the turbinate and the nasal septum is the total nasal passage. During unilateral nasal-sphenoidal approach for pituitary surgery, the nasal retractor should be entered along the common nasal passage.

1. Upper turbinate and upper nasal passage: The upper turbinate is the smallest of the three turbinates, located on the upper back of the outer side of the nasal cavity, and sometimes only a mucosal fold. The posterior ethmoid sinus opens in the upper nasal passage. The upper part of the back of the upper turbinate is the sphenoethmoid recess, where the sphenoid sinus opens. The upper turbinate and upper nasal passage also have olfactory mucosa distribution. Sometimes there is a smaller upper turbinate just behind the upper turbinate. The upper turbinate and upper turbinate are co-located in a small area behind the outer side wall of the nasal cavity.

2. Middle turbinate and middle nasal passage: The middle turbinate is a sign of the inner wall of the ethmoid sinus, which can be divided into two parts, the front part of the middle turbinate is attached to the anterior skull base bone at the junction of the top wall of the ethmoid sinus and the level of the ethmoid bone. The rear part of the middle turbinate extends backward, and the back end is attached to the lateral wall of the nasal cavity at the zygomatic vertical projection of the zygomatic bone. Where the hole is, blood vessels and nerves of the same name pass. There are two bulges on the outer side wall of the middle nasal passage. The former and the lower bulges are arc-shaped ridge-like bulges, called hook processes; the posterior upper bulges are ethmoid vesicles and belong to the ethmoid sinus structure. There is a semilunar fissure between the two, which is called a semilunar fissure. The funnel-shaped space that gradually expands downward and forward and outward of the meniscus is the sieve funnel, the inner boundary of the sieve funnel is the hook process, the outside is the orbital cardboard, the front and upper are the maxillary frontal processes, and the outer and upper are the lacrimal bones. Inward meniscus communicates with the middle nasal passage, the frontal boundary is the blind end, the frontal upper part is called the frontal recess, and the frontal sinus opens through the frontal canal or frontal recess to the upper front of the ethmoidal funnel, followed by the frontal ethmoidal sinus. The opening, and finally the opening of the maxillary sinus.

Lift up the middle turbinate, and you can easily observe the hook process from the sagittal plane anatomy specimen. The hook process is almost sagittal, almost parallel to the ethmoid vesicles, the trailing edge is free, and the front of the hook process is attached to the maxilla. The ethmoid is located just below the front of the middle turbinate and the attachment of the nasal mound to the outer wall of the nasal cavity. Immediately below it, the hook process merges with the posterior part of the lacrimal bone. This attachment is thicker in bone, and the uncinate process often diverges or widens here, and then fuses with the solid inferior turbinate bone. The upper boundary of the uncinate process divides a small bony protrusion to attach to the vertical plate of the jawbone.

The sieve bubble is the largest and most constant air cell in the front screen. It is located in the middle nasal tract, just behind the hook process. The ethmoid vesicles are based on orbital cardboard and protrude inward into the middle nasal passage. The sieve bubble looks like a bubble and is a hollow, thin-walled, round bony protrusion. The front wall of the ethmoidal vesicles can reach the base of the anterior skull upward, forming the posterior boundary of the frontal recess; the ethmoidal vesicles can be integrated with the middle nasal methyl plate backwards.

In the lateral expansion of the transsphenoidal approach, the middle turbinate needs to be removed along the middle nasal methyl plate. If not necessary, do not damage the lateral structure of the middle nasal passage.

Inferior turbinate and lower nasal passage: The inferior turbinate is a single bone piece attached to the lower part of the outer wall of the nasal cavity, which is the largest of the turbinates. The inferior turbinate has a large head and a huge body backwards, and finally converges to form a thin or thick tail, the size of which depends on the degree of hyperplasia and hypertrophy of the mucosa. A funnel-shaped nasolacrimal duct opening can be seen below the front middle third of the inferior turbinate, and the eustachian tube pharyngeal orifice is located 1 to 1.5 cm from the rear end of the inferior turbinate.