Accessory muscles of respiration

Accessory Muscles of Respiration

The Accessory Muscles of Respiration are a group of muscles that aid in the process of respiration. These muscles are not primarily involved in respiration, but they assist the diaphragm and the intercostal muscles during heavy or labored breathing.

Function

The accessory muscles of respiration assist in expanding the thoracic cavity, allowing for greater movement of air into the lungs. They are typically activated during strenuous exercise, or in conditions where normal breathing is impaired, such as in COPD or asthma.

Major Accessory Muscles

The major accessory muscles of respiration include:

• Sternocleidomastoid: This muscle elevates the sternum, increasing the volume of the thoracic cavity.
• Scalenes: These muscles elevate the upper two ribs, aiding in inspiration.
• Pectoralis Major and Pectoralis Minor: These muscles lift the ribs, aiding in inspiration.
• Trapezius and Rhomboids: These muscles stabilize the shoulder girdle during respiration.

Clinical Significance

Overuse or strain of the accessory muscles can lead to conditions such as thoracic outlet syndrome or neck pain. Additionally, reliance on these muscles for breathing in conditions such as COPD can lead to respiratory failure.

See Also

• Respiratory system
• Muscles of respiration
• Breathing