Lung Anatomy

The lungs are a pair of organs located in the chest that are responsible for breathing and gas exchange. It’s important to know about lung anatomy to be able to create fastinating medical illustration with greater accuracy.

Lungs are made up of several different parts, including the trachea, bronchi, bronchioles, alveoli, and pleural membranes.

What is lung capacity?

Lung capacity refers to the amount of air that the lungs can hold at different levels of inhalation and exhalation. The lungs have several different lung capacities that can be measured, including:

1. Tidal volume (TV): The amount of air that is inhaled and exhaled with each breath during normal breathing. This is typically around 500 mL.
2. Inspiratory reserve volume (IRV): The amount of air that can be inhaled after a normal breath. This is typically around 3,000 mL.
3. Expiratory reserve volume (ERV): The amount of air that can be exhaled after a normal breath. This is typically around 1,200 mL.
4. Residual volume (RV): The amount of air that remains in the lungs after a maximum exhalation. This is typically around 1,200 mL.
5. Vital capacity (VC): The total amount of air that can be inhaled and exhaled in one breath. This is typically around 4,800 mL.
6. Total lung capacity (TLC): The total amount of air that the lungs can hold. This is typically around 6,000 mL.

These lung capacities can be measured through various techniques such as spirometry, which measures the flow of air in and out of the lungs. It’s important to note that lung capacity can vary based on factors such as age, gender, physical activity, and certain medical conditions.

The reference values for each of the volumes can be found here.

What are the 4 parts in lung anatomy?

The trachea, also known as the windpipe, is a tube that connects the lungs to the throat. It is lined with cartilage rings that help to keep the trachea open and prevent it from collapsing.

The bronchi are two branches of the trachea that enter the lungs and divide into smaller branches called bronchioles. The bronchioles are lined with smooth muscle that can contract and relax, controlling the flow of air into and out of the lungs.

The alveoli are small, balloon-like structures that are located at the end of the bronchioles. They are responsible for gas exchange and are lined with thin, moist membranes. Oxygen from the air we breathe diffuses into the bloodstream through these membranes, while carbon dioxide from the bloodstream diffuses into the alveoli to be exhaled.

The pleural membranes are thin layers of tissue that surround each lung and line the chest cavity. They produce a small amount of fluid that acts as a lubricant, allowing the lungs to move smoothly within the chest cavity during breathing.