Diaphragm Function: Primary muscle for breathing; contracts to enlarge thoracic cavity during inhalation.
Thoracic Volume Change: Inhalation increases thoracic volume, creating a vacuum that draws air in. Exhalation reduces volume, expelling air.
Muscle Involvement: External intercostal muscles assist in inhalation. Internal intercostals and abdominal muscles aid in forced exhalation.
Lung Elasticity and Surfactant: Lung recoil and surfactant in alveoli facilitate breathing process.
Breathing Regulation: Controlled by the brainstem, responding to CO2, O2 levels, and lung stretch signals.
