Structure of Nose

The structure of the nose is a complex design composed of bones, cartilage, and soft tissue. The external structure of the nose is somewhat triangular and is primarily shaped by two bones. The internal structure includes a cavity lined by mucus membrane and hair follicles that keep away foreign particles and humidify the inhaled air.

The nasal cavity is divided by a nasal septum. At the base of the nasal cavity lie the two nostrils that act as an entry to the nose. The nose is mainly innervated by the branches of the trigeminal nerve and olfactory nerve. Blood supply to both the external and internal nose is taken care of by various facial arteries that branch out from the carotids.

About Nose

The nose is the organ of smell in our body. It not only helps to smell but also helps in breathing. This organ is made up of bone, cartilage, and soft tissues and is distinctly visible on the face. The nose contains olfactory receptors that help in generating signals for identification of smell by the brain. It is believed that the nose evolved from a simple organ of olfaction to detect chemicals in aquatic organisms to a complex structure responsible for breathing, smelling, and tasting in higher vertebrates. The mammals exhibit the most evolved forms of the nose.

Diagram of Nose

A labeled diagram of the structure of the nose is given below:

Structure of Nose

The human nose is a complex structure. It can be broadly divided into two segments: external nose and internal nose. The details of the structure of the nose are discussed below:

External Structure of Nose

The external nose is the visible part of the nose on the face and comprises various structures. These structures include:

1. Tip: It is the pointed end of the nose.
2. Nostrils or the Nares: These are the two openings at the base of the nose through which air enters.
3. Alae: These are the wing-like structures on either side of the nostrils. The alae are made up of cartilage and soft tissue.
4. Nasal Bridge: This is the bony upper part of the nose that extends between the eyes.
5. Nasal Septum: This is the dividing wall between the nostrils. The anterior part of the septum is made up of cartilage whereas the posterior end is made up of bone.
6. Columella: It is a small strip of skin that separates the nostrils at the base of the nose.

Innervation and Blood supply: A branch of the trigeminal nerve provides sensory innervation to the skin of the external nose and blood supply is maintained by the branches of the facial artery that arise from the carotid artery.

Internal Structure of Nose

The internal structure of the nose includes the large empty cavity called nasal cavity. This cavity is divide into section by the nasal septum. The lateral walls of the nasal cavity have three bony projections called nasal conchae or turbinates that increase the surface area of the nasal cavity and help humidify, filter, and warm the inhaled air. There are spaces between the nasal conchaes that directs the flow of air. These spaces are called nasal meastuses.

• The anterior part of the nasal cavity is called the nasal vestibule. This region is lined with skin containg hair follicles and sebaceous glands. On moving up into the nasal cavity we encounter the region that contains olfactory cells which are specialised for the sense of smell.
• The nasal cavity continues to connect with hollow cavities called paranasal sinuses. There are four pairs of paranasal sinuses that produces mucus and maintain the resonance of sound. A duct called nasolacrimal duct unites with the tear duct that allows the flow of tears into the nose.

Innervation and blood supply: The branches of trigeminal nerve and olfactory nerve inervates the internal nose. Blood supply is maintained by different facial arteries.

Function of Nose

Nose is one of the five sense organs in the body. It is the primary organ of smell and respiration in body. the functions of nose are discussed below:

1. Breathing: The primary function of the nose is to facilitate the process of breathing. Exhalation and inhalation occurs through the nose and helps in intake of oxygen rich air and removal of carbon dioxide.
2. Smell : The nose is a crucial organ for the sense of smell. The olfactory receptors in the nasal cavity detect and identify various odors, sending signals to the brain that contribute to our perception of taste and our ability to recognize and enjoy different scents.
3. Taste: The nose not only helps in smelling but also helps in tasting as when we chew the food the chemicals from the food activates the olfactory receptors and helps to identify the actual falvour of food.
4. Purification of inhaled air and protection of respiratory tract: The nose plays a role in protecting the respiratory system. The hair in the nasal passages, along with mucus production, help to trap and remove particles and pathogens thus prevent them from reaching the lungs and cause respiratory infections.
5. Speech and Voice Resonance: The paranasal sinuses within the nose contribute to the resonance of the voice. The shape and structure of the nasal cavity influence the quality of speech and the characteristics of vocal tones.
6. Nasal Reflexes: The nose is involved in various reflex actions, such as sneezing.

FAQs on Structure of Nose

1. What two structures make up the nose?

The two structures that make up the nose are bones and cartilage. The bones form the structure of the nose while the cartilage forms the flexible part of the nose.

2. What are the functions of the parts of the nose?

The parts of nose together carry out vital functions of the body. Like the nostrils allow the inhalation of air, while the nasal cavity, lined with mucous membranes, humidifies and filters the air, trapping particles and microbes. The nasal septum divides the nasal cavity, contributing to structural stability and the olfactory region serves in recognition of smell and flavour.

3. What are the layers of the nose anatomy?

The anatomy of the nose includes three layers. The outer layer formed by skin and associated structure. It provides protection. The middle layer made up of cartilage and bone. It forms the structural framework of the nose. And the inner layer, that is a mucous membrane lining the nasal cavity. It contributes to humidification and filtration of air.

4. What is the muscle anatomy of the nose?

The muscle anatomy of the nose includes the Procerus muscle that is located between the eyebrows and spans from the lower nasal bone to the upper forehead. The Nasalis that along with various components, surrounds and extends along the sides of the nostrils. The Depressor Septi Nasi, the Levator labii Superioris Alaeque Nasi, and the orbicularis oris located on the upper lip region.

5. How many bones are in the nose?

There are two bones in the nose. They are oblong bones whose superior border and the main body forms the nasal bridge and the inferior border connects with the cartilage to form the margin of the nasal aperture.