Lungs: where they are located, how they are structured, and what healthy lungs look like

The lungs are a pair of spongy, pinkish-gray organs in the chest cavity through which oxygen from the air enters the blood and carbon dioxide returns to the outside. On an ordinary day, a person takes about 25,000 breaths in and out and hardly notices this work — until breathing starts to sound different. Below is information about where the lungs are located, how they are structured, and what healthy lungs look like.

Lungs: what kind of organ is this and what is it needed for

The lungs are the central part of the respiratory system. In addition to them, it includes the trachea, the muscles of the chest wall and the diaphragm, blood vessels, and other tissues: together, all of this makes breathing and gas exchange possible. When you inhale, air enters the lungs, and oxygen passes into the blood, where red blood cells carry it throughout the body. At the same time, carbon dioxide, a waste gas, passes from the blood into the lungs and is exhaled. This process is called gas exchange, and without it life is impossible. The breathing rate — how often and how deeply you breathe — is regulated by the brain: it senses the body's need for oxygen and the need to get rid of carbon dioxide.

Where the lungs are located and which organs are nearby

The lungs occupy most of the thoracic cavity, which is bounded by the rib cage and separated from the abdominal cavity by the thoracoabdominal barrier — the diaphragm. A person has two lungs, right and left; on the outside, each is covered by the visceral pleura, and the thoracic cavity and diaphragm are lined on the inside by the parietal pleura. Nearby are the trachea, through which air travels to the lungs, the heart, major vessels, the esophagus, the muscles of the chest wall, and the diaphragm. The shape of the lungs constantly changes depending on the phase of breathing — on inhalation and exhalation.

Structure of the lungs: bronchi, bronchioles, and alveoli

The main bronchus enters each lung and branches into increasingly smaller bronchi; their diameter decreases, and the small bronchi transition into terminal bronchioles. Beyond them begins the respiratory section, which performs the gas-exchange function. The alveoli, the pulmonary sacs, are separated by thin septa in which blood capillaries run; there are tiny pores between adjacent alveoli. The barrier between blood and air does not exceed 0.5 µm. Surfactant — a substance coating them from the inside — prevents the alveoli from collapsing on exhalation; it contains phospholipids, proteins, and glycoproteins. Surfactant also protects the alveoli from microorganisms in inhaled air and from fluid leaking from the capillaries.

What healthy lungs look like

Healthy lungs are described as spongy and pinkish-gray: their tissue is soft, porous, and filled with air. A linguistic detail is also known: the Russian name of the organ is connected to the fact that when a carcass is butchered, the lungs float on water, while other organs sink. Externally, these are paired organs in the chest cavity that work quietly, like a steady background — a person does not think about every breath. During an appointment, the doctor listens to breath sounds and assesses how breathing sounds over different areas of the chest.

What can disrupt lung function

The term "lung diseases" unites many conditions: asthma, chronic obstructive pulmonary disease, infections — influenza, pneumonia, tuberculosis — lung cancer, and other breathing problems. Some of these diseases can lead to respiratory failure. A common sign is labored breathing: the person has difficulty breathing.

When to see a doctor

A reason to talk to a doctor is labored breathing and blood when coughing; the assessment is made by a doctor. During an appointment, the doctor clarifies the history, listens to breathing, and, if necessary, orders tests:

• pulmonary function tests and spirometry;
• pulse oximetry — measurement of blood oxygen saturation;
• blood gas analysis;
• bronchoscopy with bronchoalveolar lavage or lung biopsy;
• PET scanning of the lungs and plethysmography.

The doctor decides which tests are needed.

Labored breathing by itself is not a reason to call an ambulance; 103/112 — for a life-threatening condition when a person suddenly and severely lacks air or is coughing up blood.

This material is for reference: it helps to understand how the lungs are structured but does not replace a doctor's consultation — if in doubt, see a specialist.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer