Question

Internal nasal valve.

Hint:

The internal nasal valve plays a vital role in regulating nasal airflow and breathing. Dysfunction of this valve often leads to significant nasal obstruction and difficulty breathing.

Answer 1

Step 1: Definition of Internal Nasal Valve.
The internal nasal valve is a critical anatomical structure in the nose, contributing significantly to nasal airflow and resistance. It is located in the nasal vestibule, where the lower lateral cartilage meets the upper lateral cartilage and the septum. It is the narrowest part of the nasal airway, and its function plays a crucial role in maintaining proper nasal breathing.
Step 2: Anatomy of the Internal Nasal Valve.
The internal nasal valve is defined by the following anatomical landmarks:
(1) Septum (medial wall): The nasal septum forms the medial boundary of the valve.
(2) Upper Lateral Cartilage (superior wall): The upper lateral cartilage forms the upper border of the valve.
(3) Lower Lateral Cartilage (inferior wall): The lower lateral cartilage forms the inferior border of the valve.
(4) Nasal Floor (lateral wall): The lateral nasal wall, primarily made up of the maxilla and palate, helps shape the external appearance of the valve.
The angle of the internal nasal valve is typically around 10-15 degrees, and any narrowing of this area can lead to nasal obstruction or difficulty breathing.
Step 3: Function of the Internal Nasal Valve.
The internal nasal valve is primarily responsible for regulating airflow through the nasal passages. Its main functions include:
(1) Regulating Nasal Airflow Resistance: The valve controls the resistance to airflow by adjusting its diameter during breathing. When the internal nasal valve narrows, it increases the resistance, and vice versa.
(2) Humidifying and Filtering Air: The valve helps warm, humidify, and filter the inspired air as it passes through the nasal cavity.
(3) Protecting the Lower Airways: By adjusting the airflow, the nasal valve helps protect the lungs from dust, pollutants, and pathogens.
Step 4: Dysfunction of the Internal Nasal Valve.
When the internal nasal valve is compromised, it can result in symptoms of nasal obstruction. Common causes of dysfunction include:
(1) Structural Abnormalities: A deviated septum, overdeveloped turbinates, or trauma to the nasal cartilage can narrow the valve.
(2) Aging: The natural aging process can cause weakening or loss of elasticity in the nasal tissues, resulting in valve collapse.
(3) Surgical Changes: Over-resection during nasal surgery can reduce the structural integrity of the nasal valve, leading to obstruction.