ACCESSORY MUSCLES OF RESPIRATION Meaning and
Definition
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Accessory muscles of respiration refer to a group of muscles that assist in the process of breathing or respiration in addition to the primary muscles involved in this function. These muscles are responsible for additional force and support during inspiration and expiration, helping to expand and contract the lungs to enable efficient breathing.
The main accessory muscles of respiration include the sternocleidomastoid, scalene muscles, pectoralis muscles, and abdominal muscles. The sternocleidomastoid muscles are located in the neck and aid in lifting the ribcage during inhalation. The scalene muscles, also found in the neck, elevate the upper ribs during deep inhalation.
The pectoralis muscles in the chest assist in elevating the ribcage and increasing lung capacity. The abdominal muscles, including the rectus abdominis and external and internal obliques, are involved in forced expiration, pushing the air out of the lungs more forcefully.
The accessory muscles of respiration are typically activated during exercise or when breathing becomes more difficult, such as in cases of respiratory distress or certain lung conditions. When these muscles are engaged, it indicates that the primary muscles involved in breathing, such as the diaphragm and intercostal muscles, may need additional support to ensure adequate ventilation. Therefore, the recruitment of accessory muscles is a compensatory mechanism to facilitate improved breathing when needed.
