Question

1
Expiration involves :
a. Relaxation of diaphragm and intercostals
muscles.
Contraction of diaphragm and intercostals
muscles.
Contraction of diaphragm muscles.
d. Contraction of intercostal muscles.​

Answer 1

Answer:

Hi frnd expiration, this is an active process. It involves contraction of the abdominal muscles which forces the diaphragm upwards reducing the volume of the thoracic cavity. this is your answer.

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