Final answer:
The thoracic cavity contains the lungs and heart, where systemic and pulmonary circulation occur. The heart's four chambers facilitate blood flow, and the coronary circulation system nourishes the heart muscle. Newborn hearts and adult hearts have anatomical differences, and lung capacity can be assessed through specific measurements.
Step-by-step explanation:
Thoracic Cavity Anatomy and Function
The thoracic cavity is a central compartment of the chest, containing the lungs, heart, and major blood vessels. Within the thoracic cavity, the heart is positioned in the pericardial cavity, which is a subset of the superior mediastinum. The heart comprises four chambers: two atria and two ventricles, responsible for receiving deoxygenated blood and pumping oxygenated blood, respectively.
Comparing systemic circulation to pulmonary circulation, the former carries oxygenated blood from the left side of the heart to the body, whereas the latter carries deoxygenated blood from the right side of the heart to the lungs. The coronary circulation system, consisting of veins and arteries, provides blood to the heart muscle itself.
In newborns, the heart has an opening between the right and left atria (foramen ovale), which typically closes after birth, differentiating newborn and adult heart anatomy. The lung capacity, which can be measured through various volumes and capacities such as tidal volume and vital capacity, indicates the maximum amount of air the lungs can hold.
Issues such as V/Q mismatch can occur due to improper ventilation/perfusion balance, affecting oxygenation.