Each lung is contained within the thoracic cavity but is also surrounded by the pleural sac. False True

## Step 1<br />The problem statement is a statement about the anatomical structure of the human respiratory system. It states that each lung is contained within the thoracic cavity but is also surrounded by the pleural sac.<br />## Step 2<br />To solve this problem, we need to verify the accuracy of this statement. The thoracic cavity is indeed the part of the body where the lungs are located. However, the statement also mentions that each lung is surrounded by the pleural sac.<br />## Step 3<br />The pleural sac, also known as the pleura, is a double-layered membrane that surrounds each lung. The inner layer, known as the visceral pleura, is in direct contact with the lung tissue. The outer layer, known as the parietal pleura, is attached to the chest wall.<br />## Step 4<br />The pleural sac creates a closed, lubricated space known as the pleural cavity. This cavity allows the lungs to expand and contract smoothly during breathing.<br />## Step 5<br />Given this information, the statement in the problem is indeed true. Each lung is contained within the thoracic cavity and is also surrounded by the pleural sac.