What are the accessory muscles of respiration? Understanding their role in breathing

The accessory muscles of respiration are vital but frequently disregarded parts of the respiratory system.

These are the muscles that are not primarily in charge of respiration but can help with it when necessary, such as during exercise, or when the primary muscles of respiration are insufficient to achieve adequate gas exchange. It might happen in conditions like chronic obstructive pulmonary disease (COPD) or asthma.

The diaphragm and the intercostal muscles are the main breathing muscles. The accessory muscles of respiration are used to support the respiratory effort when breathing becomes challenging or hard.

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Types of accessory muscles of respiration

During physical activities, accessory muscles may be employed. (Image via Unsplash)

External intercostals: The muscles known as the external intercostals, which are situated between the ribs, aid in raising the rib cage during inhalation to enlarge the chest cavity. The capacity of the lungs is increased by this process.

Scalene: The scalene muscles, which are located in the neck, raise the upper ribs when contracted. These are especially helpful while you are exercising or trying to catch your breath when you are breathing heavily or laboriously.

Sternocleidomastoid: When breathing deeply, the muscle in the neck known as the sternocleidomastoid aids in lifting the sternum and clavicle. When you take deep or strong breaths, it becomes more active.

Abdominal muscles: While frequently linked to core stability, the abdominal muscles also aid in breathing. The accessory muscles of respiration support the abdominal cavity's compression and the diaphragm's upward movement when you cough or sneeze vigorously.

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When do accessory muscles come into play?

Normally, when one is breathing normally and relaxed, these muscles are not usually used.

When someone tries to take a deep breath, accessory muscles of inspiration start to contract in a person with healthy lungs. Similar to blowing out a flame, when someone tries to forcibly breathe out, the accessory muscles of expiration are recruited. These muscles may spontaneously contract in a person with a respiratory issue, even during normal breathing.

The accessory muscles of respiration are used instead when the body needs more oxygen or when there is more airflow resistance, as in the following circumstances:

Exercise: Physical exertion raises the body's need for oxygen, and these muscles assist the chest cavity in expanding more effectively, enabling deeper breaths.

Respiratory distress: When breathing becomes difficult, such as during an asthma attack or when suffering from a respiratory condition, these muscles may contract to assist the body in getting past the obstruction.

Stress or anxiety: Emotional stress or anxiety can cause rapid, shallow breathing, and it may also use these muscles to maintain increased ventilation.

Chronic respiratory conditions: Because their lung function is impaired, people with chronic lung conditions such as chronic obstructive pulmonary disease (COPD) may need to use these muscles for breathing more frequently.

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It's critical to call a doctor as soon as you can if someone seems to be breathing more laboriously than usual. A method known as pursed-lip breathing may be advised by a doctor if a person with COPD is using their accessory muscles to assist with breathing. By using this breathing technique, they may be able to exhale more forcefully and eventually use less of their accessory muscles of respiration.