ANATOMY

Detailed explanation-1: -The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continually, and most of the time, involuntarily. Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges.

Detailed explanation-2: -The rib cage muscles, including the intercostals, the parasternals, the scalene and the neck muscles, mostly act on the upper part of the rib cage (pulmonary rib cage) and are both inspiratory and expiratory. The abdominal muscles act on the abdomen and the abdominal rib cage and are expiratory.

Detailed explanation-3: -Many muscles are required to help the lungs expand and tighten during breathing: The diaphragm: Located below the lungs, the diaphragm is the main muscle needed to breathe. It separates the chest and abdominal cavities and contracts to help inflate the lungs.

Detailed explanation-4: -The primary inspiratory muscles are the diaphragm and external intercostals. Relaxed normal expiration is a passive process, happens because of the elastic recoil of the lungs and surface tension.

Detailed explanation-5: -The diaphragm is the primary muscle used in respiration, which is the process of breathing. This dome-shaped muscle is located just below the lungs and heart. It contracts continually as you breathe in and out.