Question 12
RespirationUse the following processes to answer this question.
I. Ribs move upward and outward
II. Diaphragm relaxes
III. Volume of thorax increases
IV. Air is forced out of the lungs
Which of the processes is a direct result of contraction of the intercostal muscles?
- A.I
- B.II
- C.III
- D.IV
Show the answer and explanation
Answer: A (I)
Explanation
The intercostal muscles lie between the ribs; when they contract they lift the ribs up and out, which then enlarges the chest.