The nose is the primary organ of the respiratory system. It allows the entry of air into the body. Air enters through the nostrils and is warmed, moistened, and filtered, preventing harmful particles from entering the lungs. The hairs inside the nose, called cilia, help filter out dust, pollen, and other particles from the air we breathe.

The nose also contributes to our sense of smell and plays a role in shaping our facial appearance. The human nose can distinguish around 1 trillion different smells. Our sense of smell is incredibly powerful and can detect various scents.

Interestingly, approximately 80% of our taste perception is influenced by our sense of smell. This explains why we may experience a significant reduction in the taste of food when our nasal passages are congested or blocked.

Anatomy

The nose comprises the following structures:

• Hair and cilia: Inside the nose are hair and tiny structures called cilia, which capture dirt and particles. They then move these particles towards the nostrils, allowing them to be expelled through sneezing or wiped away.
• Nasal cavities: The nose contains two nasal cavities, hollow spaces through which air flows in and out.
• Nostrils (nares): These are the openings on the face through which the air enters the nasal cavity.
• Nasal septum: The nasal septum is a wall of bone and cartilage that divides the nasal cavity into two sides.
• Sinuses: The sinuses are air-filled cavities connected to the nasal cavity. They produce mucus that keeps the nose moisturized.
• Turbinates (conchae): The turbinates are bony structures on the side walls of the nasal cavity. They help warm and humidify the air after inhalation and assist with nasal drainage.

Functions

• Breathing: The nose’s primary function is to allow air passage into the respiratory system.
• Smell: The nose contains olfactory receptors that enable us to detect and differentiate various scents, contributing to our sense of smell.
• Speech and Voice: The nasal cavity and sinuses affect the quality and resonance of our voice during a speech by acting as resonating chambers.
• Protection: The nose, with its hairs and mucus-producing cells, acts as a defense mechanism by trapping dust, bacteria, and other foreign particles, preventing them from reaching the lungs.
• Moistening: The nasal mucous membranes help add moisture to the inhaled air, preventing dryness and irritation of the respiratory tract.