Nepedia
Back to Discover
Advanced Reader
🧬

Human nose

life science Maturity 9-11 Next article →

The human nose serves as the primary entry point for the respiratory system. It also functions as the central organ for the olfactory system, which allows for the sense of smell. This complex structure is shaped by a combination of nasal bones and various nasal cartilages. A central wall known as the nasal septum divides the internal nasal cavity into two distinct passages.

Anatomy of the human nasal cavity
Anatomy of the human nasal cavity

Beyond breathing and smelling, the nose plays a role in speech and sound modification. It is a highly specialized organ designed to protect, condition, and sense the environment.

When you inhale, the nose performs several critical conditioning steps. First, nasal hair located in the nostrils acts as a filter to catch large particles. This prevents debris from moving deeper into the lungs. The nasal mucosa, a moist lining, then warms and moistens the air.

Gray45
Gray45

This process is aided by the nasal conchae, which are shell-like bones within the nasal cavity walls. If an irritant touches the mucosal lining, the body triggers a sneezing reflex. This reflex expels unwanted particles through aerosols, which can sometimes transmit infections.

Mouth and pharynx
Mouth and pharynx

The internal structure of the nose is a sophisticated bony-cartilaginous framework. The upper bony portion is formed by the frontal bone and the maxilla.

714 Bone of Nasal Cavity
714 Bone of Nasal Cavity

The internal roof of the nasal cavity features the cribriform plate of the ethmoid bone. This perforated plate allows the olfactory nerve's sensory fibers to pass through. The nasal septum provides the midline division, consisting of bone at the top and cartilage near the tip. The floor of the nose is created by the incisive bone and the palatine bones, forming the hard palate.

Sobo 1909 100
Sobo 1909 100

Cartilage provides the necessary flexibility for the nose to function and move. The septal cartilage extends from the nasal bones down to the floor of the cavity. Several other cartilages, such as the lateral and alar cartilages, shape the external appearance.

Gray852
Gray852

The major alar cartilages are U-shaped plates that form the walls of the vestibule. These cartilages include the medial and lateral crura, which meet at the columella. A structure called the nasal scroll helps prevent the airway from collapsing due to airflow pressure. This arrangement allows the nostrils to be modified by muscle control.

A variety of facial muscles are responsible for the movements of the nose. The procerus muscle can wrinkle the skin over the bridge of the nose during concentration. The nasalis muscle has two parts: the compressor naris, which can close the nostrils, and the dilator naris, which flares them.

Anatomy of the human nasal cavity
Anatomy of the human nasal cavity

The depressor septi nasi muscle can pull the tip of the nose and the septum downward. These muscles are part of a continuous layer called the superficial muscular aponeurotic system, or SMAS. This system connects the muscles and ligaments from the nasal tip to the forehead.

The soft tissues of the nose vary significantly in thickness and composition. The skin is thick and flexible near the glabella but becomes very thin at the bridge.

Topinard nasal index
Topinard nasal index

At the tip, the skin is thick again and contains many large sebaceous glands. Beneath the skin, there are four distinct layers: a superficial fatty layer, the fibromuscular SMAS layer, a deep fatty layer, and the periosteum. The nasal cavity itself is divided into the nasal vestibule and the nasal cavity proper. The vestibule is the front part, lined with skin and hair follicles.

Understanding the nose also involves looking at how it affects sound and medical care. The paranasal sinuses are hollow cavities that act as sound chambers. These chambers help to modify and amplify vocal sounds during speech. Nasalisation is the process used to produce specific nasal vowels and consonants. Because of its importance, doctors may perform rhinoplasties to correct structural defects.

724 Paranasal Sinuses
724 Paranasal Sinuses

These can be reconstructive surgeries for trauma or congenital issues, or elective cosmetic surgeries to change the nose's shape.

633 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (13)
File:714 Bone of Nasal Cavity.jpg
714 Bone of Nasal Cavity.jpg
File:Sobo 1909 100.png
Sobo 1909 100.png
File:Gray852.png
Gray852.png
File:Anatomy of the human nasal cavity.png
Anatomy of the human nasal cavity.png
File:724 Paranasal Sinuses.jpg
724 Paranasal Sinuses.jpg
File:Topinard nasal index.png
Topinard nasal index.png
File:Blausen 0170 CarotidArteries.png
Blausen 0170 CarotidArteries.png
File:Arteries of the Nose.jpg
Arteries of the Nose.jpg
File:Gray45.png
Gray45.png
File:Mouth and pharynx.png
Mouth and pharynx.png
File:1403 Olfaction.jpg
1403 Olfaction.jpg
File:Facies of Heredosyphilis 5.jpg
Facies of Heredosyphilis 5.jpg

+ 1 more

More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.