How Your Lungs Work: A Guide to Lung Function and Anatomy

Behind every breath is a pair of lungs working hard to supply the oxygen you need for daily life. But have you ever wondered how your lungs carry out their complex processes in a matter of seconds?

Keep reading to learn more about your lungs, including how they function, their anatomy, common diseases, how to maintain lung health and answers to commonly asked questions.

The Necessity of Your Lungs

Every cell in your body requires oxygen to support its essential functions. Without it, your cells, organs and bodily functions begin to fail. The good news is that your lungs' primary role is to seamlessly provide oxygen to your body. Beyond respiration, healthy lungs support many nonrespiratory functions, including:

• Acid-base balance
• Blood filtration
• Blood pressure regulation
• Immune system defense

It’s important to know not only what your lungs do but also how they do it.

The Function of Your Lungs

Your lungs are the two balloon-shaped organs that sit behind your ribs, made of spongy tissue, air sacs and blood vessels, responsible for bringing oxygen into the body. Once in your lungs, oxygen is transported into your bloodstream and distributed throughout the body. Each cell in your body uses oxygen and produces carbon dioxide. When the carbon dioxide leaves the cell, your bloodstream carries it back to the lungs, where it’s expelled through exhalation. Besides oxygen exchange, your lungs also:

• Bring air to the proper body temperature
• Moisturize the air to the proper humidity level
• Protect the body from harmful substances by coughing, sneezing, filtering or swallowing them
• Support your sense of smell

Breathing begins with inhalation through your nose and mouth. Air travels through your pharynx and larynx (the throat), down your trachea (windpipe), through the branches of your lungs called the bronchioles, and into tiny air-filled sacs called alveoli. Once the gas exchange occurs, carbon dioxide then travels back out through your mouth and throat.

How Does Breathing Work?

Your brain’s autonomic nervous system stimulates breathing by sending signals to your diaphragm, the large muscle at the base of your chest. These signals tell your diaphragm to flatten and move downward. At the same time, the muscles between your ribs contract, pulling your ribcage upward and outward to expand your chest cavity. As your chest cavity expands, the pressure inside your lungs decreases. Air then rushes through your nose and mouth to equalize that pressure.

Anatomy of the Lungs

Your lungs include lobes, the bronchi, pleura, pleural cavity and alveoli. Let’s take a closer look at each.

Lobes

Both of your lungs have lobes. However, because the right lung is slightly larger, it contains three lobes, upper, middle and lower, separated by fissures. The left lung contains only the upper and lower lobes because it’s slightly smaller, with an indentation called the cardiac notch to make room for your heart. The lobes are responsible for extracting oxygen from the air you breathe in, as well as transferring it into your bloodstream and expelling it as carbon dioxide.

Bronchi, Pleura and Pleural Cavity

The bronchi are the main airway tubes that carry air from the trachea into the lungs. The trachea divides into a right and left bronchus, which branch repeatedly into smaller airways. This network of branching airways is called the bronchial tree. The smallest airways are called bronchioles, which lead to tiny air sacs called alveoli, where oxygen and carbon dioxide are exchanged.

The pleura is a thin, two-layered membrane that surrounds each lung. The inner layer covers the lungs, while the outer layer lines the inside of the chest wall. Between these layers is a thin, fluid-filled space called the pleural cavity. This space contains a small amount of pleural fluid that reduces friction and allows the lungs to expand and contract smoothly as you breathe.

Alveoli

The alveoli are tiny, balloon-like air sacs located at the ends of alveolar ducts, which branch from bronchioles, the smallest airways in the lungs. The alveoli are where the respiratory and circulatory systems meet, allowing oxygen from inhaled air to enter the bloodstream and carbon dioxide to move from the blood into the lungs to be exhaled.

Common Lung Diseases and Their Impact

Three of the most common diseases that affect the lungs are asthma, chronic obstructive pulmonary disease (COPD) and lung cancer.

Asthma

Asthma is a chronic inflammatory lung disease. When someone with asthma encounters a trigger, their airways respond by swelling, constricting and producing extra mucus, all of which block airflow, making it difficult to breathe. Common breathing symptoms associated with asthma include:

• A persistent cough
• Shortness of breath
• Tight, painful feeling in the chest
• Wheezing

When it comes to managing asthma, we recommend:

• Drinking plenty of water
• Remaining aware of your symptoms and triggers, and avoiding them
• Safely exercising
• Understanding how to use your type of inhaler
• Using a spacer on the end of your inhaler for better inhalation of the medication

Chronic Obstructive Pulmonary Disease (COPD)

COPD is a progressive lung disease that damages the lungs, causing inflammation and restricted airflow. The two conditions included in COPD are emphysema and chronic bronchitis. However, most people with COPD show signs of both. This condition damages the lungs by inflaming the airways, destroying alveoli and trapping air within them. Common symptoms of COPD include shortness of breath, persistent coughing, frequent mucus production, wheezing, chest tightness and fatigue. The main treatment methods for COPD include:

• Medications
• Oxygen therapy
• Pulmonary rehabilitation
• Surgery

Lung Cancer

Lung cancer occurs when abnormal cells in the lungs grow uncontrollably. These cells then form tumors that damage surrounding tissues and can spread to other parts of the body. Over time, lung cancer can obstruct your airways and lead to excess mucus production, which can cause recurring respiratory infections like pneumonia.

The best way to prevent lung cancer is to avoid smoking. According to the Centers for Disease Control and Prevention (CDC), cigarette smoking and secondhand smoke exposure cause nearly 9 out of 10 lung cancer deaths. Routine lung cancer screenings are also vital for detecting and managing lung cancer because it’s most treatable when caught early. Common treatments for lung cancer include surgery, radiation and chemotherapy.

How to Maintain Lung Health and Prevent Diseases

When it comes to maintaining lung health and preventing diseases, we recommend:

• Eating a healthy diet
• Exercising regularly in a way that’s safe for you
• Getting vaccinated
• Improving your indoor air quality
• Regularly getting screened
• Remaining aware of early warning signs
• Staying hydrated
• Stopping or avoiding smoking

Rest assured, our board-certified pulmonologists and expert care teams are dedicated to helping you take your next breath with ease. If you have questions about your lung health or are experiencing new symptoms, please don’t hesitate to talk to your doctor. The compassionate healthcare you deserve is here for you.

Supporting Your Lungs With Every Breath

You take 22,000 breaths a day — each one just as vital as the last. Because your lungs are essential to your whole health, we offer comprehensive pulmonary care services to help you take your next breath with ease. Find a dedicated pulmonologist near you for the expert lung care you deserve.