Lungens

The lungs are a pair of large, spongy organs located in the thoracic cavity. They function as the primary organs of respiration, enabling gas exchange between the air we inhale and the blood. Through this process, oxygen is absorbed and carbon dioxide is expelled.

Each lung is divided into lobes: the right lung has three lobes (upper, middle, lower) and the left lung has two (upper and lower). The lungs are enclosed by pleural membranes and connected to the airways through the trachea, which divides into the right and left main bronchi and further into smaller bronchioles. Gas exchange takes place in the microscopic alveoli, clusters of air sacs surrounded by capillaries. The lungs receive blood via the pulmonary arteries and drain via the pulmonary veins; the bronchial arteries provide systemic blood to the airways.

Physiologically, ventilation moves air into and out of the lungs, creating a surface for gas diffusion. Alveolar oxygen diffuses into the blood and carbon dioxide diffuses in the opposite direction, driven by partial pressure gradients. The process is supported by surfactant, which reduces surface tension and prevents alveolar collapse, and by the respiratory muscles, especially the diaphragm and intercostal muscles.

Clinical relevance: lung disorders include chronic obstructive pulmonary disease (COPD), asthma, pneumonia, lung cancer, pulmonary embolism, and pneumothorax. Diagnosis relies on imaging (chest X-ray, CT) and functional tests such as spirometry and diffusion capacity measurements. Treatments target the underlying condition and may include bronchodilators, anti-inflammatory medications, antibiotics, oxygen therapy, and surgical interventions in selected cases.