Question

24.3. diagram the elements of the respiratory system, and show how air moves through it.
complete the following passage.
if youve ever tried to hold your breath for a long time, you know that you eventually experience an overwhelming urge to inhale. but did you know that the concentration of o₂ in your bloodstream is the signal that leads to this inhalation? the is the sheet of smooth muscle that is stimulated by this signal. when this muscle and moves downward, the chest cavity expands and allows the to also expand and draw in air. this air travels to the where o₂ is taken up by the bloodstream and co₂ released to be exhaled.
lungs relaxes glomeruli alveoli diaphragm contracts trachea

Explanation:

The passage describes the respiratory process. The diaphragm is the smooth muscle involved in inhalation; it contracts to expand the chest cavity, allowing lungs to expand. Gas exchange (O₂ uptake, CO₂ release) occurs in alveoli.

Answer:

If you've ever tried to hold your breath for a long time, you know that you eventually experience an overwhelming urge to inhale. But did you know that the concentration of O₂ in your bloodstream is the signal that leads to this inhalation? The diaphragm is the sheet of smooth muscle that is stimulated by this signal. When this muscle contracts and moves downward, the chest cavity expands and allows the lungs to also expand and draw in air. This air travels to the alveoli where O₂ is taken up by the bloodstream and CO₂ released to be exhaled.