What role do scalene muscles primarily serve?

The scalene muscles primarily serve as accessories to inhalation. These muscles, which are located in the lateral aspect of the neck, consist of three distinct parts: anterior, middle, and posterior scalene. During inhalation, the scalene muscles contract to elevate the first and second ribs, thereby expanding the thoracic cavity. This action aids in increasing the volume of the chest during breathing, facilitating the flow of air into the lungs.

While other muscles are involved in various movements like hip rotation, neck extension, or forearm flexion, the primary role of the scalene muscles is specifically associated with the respiratory process. Their function as accessory muscles becomes particularly important during deep or labored breathing, such as during exercise or respiratory distress, when more significant ventilation effort is required. Understanding the unique role of the scalene muscles in the context of respiration is crucial for recognizing their importance in overall muscular and respiratory function.