THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -The diaphragm separates the abdominal and thoracic cavities but does allow certain structures to pass through via its three openings: The inferior vena cava passes through the diaphragm at the vena caval foramen.

Detailed explanation-2: -The diaphragm, located below the lungs, is the major muscle of respiration.

Detailed explanation-3: -The diaphragm should be viewed as two distinct muscles, crural and costal, which act in synchrony throughout respiration. However, the activities of these two muscular regions can diverge during certain events such as swallowing and emesis.