Question

wednesday 9/10: lung model lab
why do the muscles involved in breathing work harder during exercise?

a) because the body needs more oxygen, so breathing muscles contract more to bring in extra air
b) because breathing muscles get tired and stop working during exercise
c) because the heart pumps slower during exercise
d) because the lungs shrink and need help inflating

Explanation:

• Option A: During exercise, the body's metabolic rate increases, requiring more oxygen for cellular respiration (to produce energy). The respiratory muscles (like the diaphragm and intercostal muscles) contract more frequently and forcefully to increase ventilation (bring in more air with oxygen).
• Option B: Breathing muscles do not stop working during exercise; they work harder to meet oxygen demands.
• Option C: The heart pumps faster during exercise to deliver oxygen - rich blood to muscles, not slower.
• Option D: Lungs do not shrink during exercise; they expand more as breathing rate and depth increase.

Answer:

A) Because the body needs more oxygen, so breathing muscles contract more to bring in extra air