S3 teaching practice ppt 4

1. PRESENTED BY,
ANCY. A.R
Natural Science
Christ Nagar College Of Education

2. Just beneath the lungs
is a thin sheet of muscle
called the diaphragm.

3. INHALATION
 During inhalation, the
diaphragm contracts and moves down; the
muscles attached to the ribs contract and
pulls the ribs outwards.
 As a result, the size of the chest
cavity increases, the lungs expand and
oxygen-rich air is inhaled into the lungs.

4. EXHALATION
 During exhalation, the
diaphragm relaxes and moves up; the
muscles attached to the ribs relax and the
ribs move inwards.
 As a result, the size of the chest
cavity decreases, the lungs contract and air
rich in carbon dioxide is exhaled from the
body.