Pleura:The pleura are two thin layers of tissue that wrap around the lungs and line the inside of the chest cavity.
Respiratory System:The respiratory system is a network of organs and tissues that help you breathe, involving the exchange of oxygen and carbon dioxide between your body and the environment.
Friction: In physiology, friction refers to the resistance encountered by surfaces when they move over each other, which can also apply to internal movements such as lung expansion during breathing