Which muscle regulates the airflow in the respiratory system? diaphragm heart lymph node lung

The correct answer is: diaphragm

The diaphragm, a thin sheet of skeletal muscle that forms the floor of the thorax, is the primary muscle of respiration in the human body. When the diaphragm contracts, it moves a few inches inferiorly into the abdominal cavity, expanding the space within the thoracic cavity and drawing air into the lungs.

Explanation: I hope this helped

activation of phospholipase c (plc) indirectly increases intracellular ions through inositol triphosphate (ip3).