The nasal cavity is the in the interior of your nose. It is lined with a mucous membrane that helps keep your nose moist by making mucus so you won’t get nosebleeds from a dry nose. There are also little hairs that help filter the air you take breaths in, blocking dirt and dust from getting into your lungs.
Nasal Cavity Function:
- The nasal cavity is the in the interior of your nose.
- Collects moisture.
- Makes a pleasing voice by resonance.
- Anti viral and anti bacteria.
- Moves mucous posteriorly to lubricate the pharynx.
- Filters particulates.
- Recirculation of air (probably).
- And olfaction (smelling stuff).
Nasal cavity structure:
The nasal cavity extends from the nostrils in the front to the choanae (the two passageways down to the pharynx) at the back. It is divided into right and left halves by the nasal septum.
The meaty exhaust into the paranasal (next to nose) sinuses:
Spheno-ethmoidal recess -> sphenoidal air sinus.
Superior meatus -> ethmoidal sinus.
Middle meatus -> maxillary sinus.
Inferior meatus -> nasolacrimal duct (the duct that drains away tears-not the same as the tear duct).
Nasal cavity bones:
In this part we’ll look at the upper part of the air passage. We’ll look at the outside nose, the nasal cavities, the paranasal sinuses, and the nasopharynx. We’ll start by looking at the bony structures that enclose these spaces.
The bony aperture for the nose is called the piriform aperture. Inside it there are two nasal cavities, a right and a left, divided in the midline by the nasal septum. To get a improved look inside we’ll divide the skull in the frontal plane along this line.
There’s a lot to see here. Let’s get ourselves leaning. Here’s the hard palate. Here’s the floor of the forward cranial fossa. Here are the medial walls of the orbits. Here are the two nasal cavities. The septum dividing them is a little off middle, which is not strange. The roof of each cavity, formed by the cribriform plate, is very narrow.
The medial wall of each nasal cavity, shaped by the septum, is smooth and dull, so is the floor. By difference the lateral wall is marked by a number of skin, most notably by these three fragile bony projections, the conchae, also known as the turbinate bones. This is the lesser concha, this is the middle concha, this is the much smaller superior concha.
The three conchae partly divide the air passage into three parts, the lower meatus, the middle meatus, and the greater meatus. Here’s the back of the orbital cavity. Below it is the hollow space in the maxilla, the maxillary antrum, which we’ll look at afterward.
At about the level of the floor of the orbit, the nasal cavity become a great deal narrower. The narrowing is reason by the presence of this collection of small hollow spaces, the ethmoid air cells. We’ll see more of these in a minute.
To see additional of the septum and the nasal cavity we’ll look at it in a skull that’s been divided just to the left of the mid-line. Here’s the bony part of the nasal septum. It’s shaped by this part of the ethmoid bone, the at right angles plate, and by this small bone that we haven’t encounter up till now, the vomer. The lowest part of the septum is shaped by the maxilla and by the palatine bone.
Here’s the divided left cribriform plate. This outcrop above it is something we’ve seen before: it’s the crista galli. The forward section we were looking at was divided here, just behind the crista galli.
Now we’ll take away the septum to get a good look at the lateral wall of the nasal cavity. The roof of the nasal cavity runs along this line, rising to its uppermost point along the length of the cribriform plate. Here are the conchae again, superior, middle, and inferior.
There are quite a few openings in the lateral walll of the nasal cavity. They’re partially hidden by the conchae. We’ll see these in a minute. The side wall of the nasal cavity is formed partly by the maxilla, partly by the ethmoid bone, and partly by the at right angles part of the palatine bone. Further back, where the nasal cavity becomes the nasopharynx, the side wall is shaped by the medial pterygoid plate.
Lateral wall of nasal cavity:
With the ordinary use of nasal endoscopes as a diagnostic and surgical tool, the structure of the lateral nasal wall has been totally rewritten. In fact the present explanation of the lateral nasal wall anatomy confirms with the endoscopic structure of the lateral nasal wall. The anatomy of the lateral nasal wall is highly changeable, and a thorough sympathetic of the anatomy is a must before happening with any nasal endoscopic process.
Nasal turbinates: The turbinate’s are the most famous feature of the lateral nasal wall. They are generally three or sometimes four in number. These turbinate’s come into view as scrolls of bone, fragile, covered by ciliated columnar epithelium. These turbinate’s sometimes may hold an air cell, in which case it is termed as a concha.
Diagrammatic representation of turbinates inside the nasal cavity:
These turbinate’s scheme from the on the side wall of the nose. Out of these turbinate’s the following are present in all individuals:
The superior , middle and lower turbinate’s. A small highest turbinate may be present in some individuals. Among these turbinate’s the greater and the middle turbinate’s are mechanism of the ethmodial compound where as the inferior turbinate is a divide bone. Commonly a fame may be seen at the anterior add-on of the middle turbinate. This importance is known as the agger nasi cell. This importance varies in size in different individuals. These agger nasi cells superimpose the lacrimal sac, alienated from it just by a thin layer of bone. Infact this agger nasi cell is measured to be a remnant of naso turbinal bones seen in animals.
When the forward attachment of the inferior and middle turbinates is removed, the lacrimal drainage system and sinus drainage system can be obviously seen.