Function of Lungs in Respiratory System

The function of the lung is to move oxygen from the air into the bloodstream and remove carbon dioxide from the blood. It plays a vital role in maintaining the body’s oxygen levels and supporting cellular function. Additionally, the lungs function to help regulate pH levels in the blood by adjusting carbon dioxide levels through breathing. In this article, we will discuss the function of the lungs in the respiratory system along with lung anatomy.

What is Lung?

The lungs are a pair of spongy, pinkish-grey organs located in the chest. They are the primary organs of the respiratory system. The lungs are located inside the chest cavity on either side of the heart. The right lung is divided into three lobes, and the left lung is divided into two lobes. 

The mediastinum separates the lungs, which contain the heart, trachea, oesophagus, and many lymph nodes. The lungs allow us to breathe. When we inhale, air enters our lungs, and oxygen from that air moves to our blood. At the same time, carbon dioxide, a waste gas, moves from your blood to the lungs and is exhaled.

Lungs Diagram

The diagram oh human lung is given below:

What are the Functions of Lungs?

The lungs are vital organs for respiration in humans and many other animals. Functions of the lungs are:

Breathing (Ventilation)

The primary function of the lungs is to facilitate the process of breathing, also known as ventilation. This involves the intake of oxygen (O2) from the air and the expulsion of carbon dioxide (CO2) produced by cellular metabolism.

Gas Exchange (Respiration)

The lungs play a crucial role in the exchange of gases between the air and the blood. In the alveoli, which are tiny air sacs within the lungs, oxygen diffuses from the air into the bloodstream, while carbon dioxide diffuses from the blood into the air for exhalation.

Oxygen Transport

Once oxygen is absorbed into the bloodstream, it binds to hemoglobin in red blood cells, forming oxyhemoglobin. This oxygenated blood is then pumped by the heart to various tissues and organs to support cellular respiration, which is essential for energy production.

Carbon Dioxide Removal

The lungs eliminate carbon dioxide, a waste product of cellular metabolism. Carbon dioxide is transported in the blood in the form of bicarbonate ions, dissolved CO2, and bound to hemoglobin. When blood reaches the lungs, carbon dioxide is released into the air during exhalation.

Regulation of Acid-Base Balance

The lungs contribute to the regulation of acid-base balance in the body by controlling the levels of carbon dioxide. By adjusting the rate and depth of breathing, the body can regulate the amount of carbon dioxide in the blood, helping to maintain proper pH levels.

Filtration and Defense

The respiratory system includes mechanisms to filter and trap foreign particles, microbes, and debris present in the inhaled air. Mucus and tiny hair-like structures called cilia in the respiratory tract help to trap and remove these substances, preventing them from reaching the lungs.

Vocalization

The lungs, along with the larynx (voice box) and other structures, play a role in speech and vocalization. The air passing through the vocal cords allows for the production of sound and speech.

Support Immune System

The lungs are consists of immune cells that defend against infections. The mucous lining, along with immune cells, helps to prevent the entry and colonization of pathogens.

Blood Filtration

As blood flows through the pulmonary capillaries surrounding the alveoli, any small blood clots or emboli that may have formed in other parts of the body can get filtered out in the lungs, preventing them from reaching critical areas like the brain.

Anatomy of Lung

The lungs are the primary organs of the respiratory system, located on either side of the heart inside the chest cavity. The right lung is slightly larger than the left lung and has three lobes, while the left lung has two. Some anatomical features of the lungs are:

• Apex: It forms the blunt upper end of the lung, located above the first rib.
• Base: It is the lower surface of the lung, which rests on the diaphragm.
• Borders: The lung has three borders: anterior, posterior, and inferior.
• Surfaces: The lung has three surfaces, which face different areas of the thorax.
• Lobes: The lungs are divided into lobes, which are separated by fissures.
• Pleura: The lungs are covered by a two-layer lining called the pleura.
• Mediastinum: It is the area that separates the lungs, which contains the heart, trachea, esophagus, and lymph node.

Lung Microbiota

The lung microbiota comprises of diverse community of microorganisms that inhabit the respiratory tract, particularly the lower airways and alveoli of the lungs.The lung microbiome is made up of a diverse bacterial community with a low biomass. The dominant phyla are Firmicutes and Bacteroidetes, and the main bacterial genera are Prevotella, Porobacteria, and Streptococcus. It helps prevent an uncontrolled inflammatory response caused by inhaling harmless environmental stimuli.

Blood Supply of Lungs

The lungs have two blood supplies: the pulmonary circulation and the bronchial circulation.

• The pulmonary circulation provides blood from the heart for oxygenation. The pulmonary arteries carry oxygen-poor blood from the heart to the lungs. 
• The bronchial circulation is a systemic vascular supply that provides oxygenated blood to the walls of the conducting airways, pulmonary arteries, and veins. The bronchial arteries supply the blood to the tissues of the lung, its lymph nodes, bronchi, and visceral pleura.

Conclusion – Function of the Lungs

The lungs are parts of the respiratory system. The function of lungs involve breathing and maintaining oxygen levels in the body and removing carbon dioxide. Lungs also help in regulating acid-base balance of the body. Additionally, the lungs function to prevent entry and colonization of pathogens. Studying the function and anatomy of lungs is important for getting a better understanding of respiratory system.

FAQs on Functions of Lungs

What are the 4 Main Structures of the Lungs?

The four main structures of the lungs are: Bronchi, Bronchioles, Alveoli and Pleura.

What are the Diseases Affecting Lung Function?

Some common diseases that can affect the lung function are: Chronic Obstructive Pulmonary Disease (COPD), Asthma, Pneumonia, Lung cancer and Cystic fibrosis.

What is the Shape of the Lungs?

The shape of the lungs is conical or pyramid-like, with a rounded apex (the top) that extends into the upper chest cavity and a broad base that rests on the diaphragm.

Where are Lungs Located?

The lungs are located in the thoracic cavity, which is the chest cavity. They are situated on either side of the heart and are protected by the rib cage.

What is the Pleura and its Function?

The pleura, a double-layered membrane, envelops the lungs and chest cavity, helping smooth respiratory motions, supporting lung position, and protecting lung function.

Which Lung is Bigger?

The right lung is generally larger than the left lung. The size difference is a normal anatomical variation and is part of the natural asymmetry within the human body.

How Many Lobes are there in the Lungs?

The right lung has three lobes, while the left lung has two lobes.

What is the Root of the Lung?

The root of the lung, also known as the hilum of the lung, is the central area where the main bronchus, pulmonary arteries, pulmonary veins, lymphatic vessels, and nerves enter or exit the lung.

What is the Function of Bronchioles?

The function of bronchioles is to carry air to and from the alveoli, which are tiny air sacs in the lungs where gas exchange occurs. They help regulate airflow and distribute air efficiently throughout the lungs during breathing.

What are the 4 Main Functions of the Lungs?

Respiration, Oxygen transport, carbon dioxide removal, and regulation of acid-base balance are the 4 main functions of the lungs.

What is the Function of the Lung Lobes?

The lung lobes facilitate efficient gas exchange, enabling oxygenation of the blood and removal of carbon dioxide. Additionally, they provide structural support and help maintain the shape of the lungs within the chest cavity.

What is the Function of Lung Alveoli?

The alveoli are tiny air sacs in the lungs where gas exchange occurs. They facilitate the transfer of oxygen from inhaled air into the bloodstream and the removal of carbon dioxide from the bloodstream into exhaled air.