BIOLOGY
JAMB 2010 - Question 20
Biology 2010 JAMB Past Questions - Question 20: The sheet of muscle that separates the thoracic and the abdominal cavities is the
Choose the most appropriate option for the gap .
A:
B:
C:
D:
Correct Answer
D
Explanation
D - Intercostal muscle is the muscle found between the ribs - which on contraction raises the ribs upwards and outwards during inspiration to increase the volume of the thoracic cavity. Conversely when the muscle relaxes, the ribs return to their original position to decrease the volume of the thoracic cavity during expiration. Pericardium is a thin membrane that encloses the heart. Pleural membranes (usually called pleura) are special membranes that envelope the lung and bear pleural fluid. The membranes prevent friction between the lung and the ribs.

