Plmânii

Plmânii is the unaccented form of the Romanian word plămânii, which denotes the lungs, the pair of organs responsible for respiration. In standard Romanian orthography the plural is plămânii; plmânii appears in non-diacritic texts.

Anatomy: The lungs lie within the thoracic cavity on either side of the mediastinum. The right lung has three lobes; the left lung has two, separated by fissures. Each lung is covered by a visceral pleura and is connected to the airway tree at the hilum.

The airway network begins with the trachea, which divides into bronchi and further into bronchioles. The distal parts terminate in alveolar sacs containing alveoli, the sites of gas exchange. The alveolar membranes are thin and are surrounded by capillaries; alveolar surfactant reduces surface tension to prevent collapse. Pulmonary arteries carry deoxygenated blood from the heart to the lungs; pulmonary veins return oxygenated blood to the heart.

Physiology: Gas exchange occurs by diffusion of oxygen into the blood and carbon dioxide out of it, supported by a large surface area and pressures that favor diffusion. Ventilation and perfusion must be well matched for efficient gas exchange. The lungs also contribute to speech, filtration of particles, and immune defense.

Development and health: Lung development begins in utero and continues after birth, with alveolarization progressing during early childhood. Aging reduces elasticity and gas exchange capacity. Common health concerns include infections such as pneumonia, chronic obstructive pulmonary disease, asthma, and lung cancer. Risk factors include smoking, air pollution, and occupational exposures; protective measures include vaccination, avoiding smoking, and regular exercise.