Question

Pick the correct statement

• A. The concentration of internal intercoastal muscles lifts up the ribs and sternum
• B. The RBCs transports oxygen only
• C. The thoracic cavity is anatomically an air tight chamber
• D. Healthy man can inspire approximately $500\, ml$ of air per minute

Answer 1

Answer: (C)

The thoracic cavity is anatomically an air tight chamber

Answer 2

The thoracic cavity is anatomically an air tight chamber as it consists of lungs that further consist of air sacs in which the air remains trapped. The contraction of the external intercostal muscles lifts up the ribs and sternum. $RBCs$ transport both $O_2$ and $CO_2$. Healthy man can inspire or expire $6000$ to $8000 \,mL$ of air per minute.