Which of the following is the most important ventilatory function of the scalene muscles? A) Activate if intrathoracic pressure falls to -40 cm H₂O. B) Elevate and fix the first seven ribs. C) Lift upper chest particularly during times of high ventilatory demand. D) Support the trachea within the thorax during heavy exercise.

Question

Quizplus · Accepted Answer

Three pairs of scalene muscles (scalenus anterior, scalenus medius, and scalenus posterior) arise from the lower five or six cervical vertebrae and insert on the clavicle and first two ribs. They lift the upper chest when active.

Which of the Following Is the Most Important Ventilatory Function