BIOLOGY
JAMB 2006 - Question 5
Biology 2006 JAMB Past Questions - Question 5: An increase in air pressure in the lungs is due to the
Choose the most appropriate option for the gap .
A:
B:
C:
D:
Correct Answer
C
Explanation
CTherelaxation of the piiiar muscles of thediaphragm returns the diaphragmto its original dome shape position. This reduces the volume cf the thoracic cavity with a corresponding increase in the pressure of air in the lungs. Air richin carbon IV oxide is exhaled. However, the contraction of theintercostal muscles results in the raising of the ribs upwards and outwards.This leads to an increase in thevolume of the thoracic cavity with a corresponding decrease In air pressure.Air rich in oxygen is taken in

