nenäkäytäviin

Nenäkäytäviin, or nasal passages, are the hollow spaces within the nose that lead from the nostrils to the pharynx. They are a crucial part of the respiratory system, playing a vital role in breathing, filtering air, and regulating its temperature and humidity before it reaches the lungs.

The inner lining of the nasal passages is covered by a mucous membrane. This membrane produces mucus, a sticky substance that traps inhaled particles such as dust, pollen, and bacteria. Tiny hair-like structures called cilia then beat rhythmically, moving the mucus towards the throat where it can be swallowed or expelled. This mechanism helps to protect the lungs from irritants and pathogens.

The nasal passages are also rich in blood vessels. As inhaled air travels through these passages, it is warmed by the blood flowing through the vessel walls, preventing cold air from shocking the delicate tissues of the lungs. Similarly, the mucous membrane moistens the air, ensuring that the lungs receive air that is properly humidified, which is essential for efficient gas exchange.

Furthermore, the nasal passages contain olfactory receptors, which are responsible for our sense of smell. When we inhale, airborne molecules interact with these receptors, sending signals to the brain that we interpret as different odors. The shape and structure of the nasal passages are optimized to direct airflow over these receptors, enhancing our ability to detect scents. Inflammation or obstruction of the nasal passages, often due to allergies or infections, can impair these functions, leading to symptoms like congestion, difficulty breathing, and reduced sense of smell.