Thoracic muscles
The thoracic muscles, or muscles of the thoracic wall, are the muscles that attach to the thoracic cage. They mainly adjust the volume of the thoracic cavity during inspiration and expiration. The thoracic muscles are grouped into intrinsic and extrinsic.
- The intrinsic muscles of the thoracic wall are the serratus posterior, levatores costarum, intercostal (external, internal, innermost), subcostal and transversus thoracis muscles. Since their primary function is to aid respiratory movements, these muscles are also known as the respiratory muscles.
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The extrinsic muscles of the thoracic wall are the subclavius, pectoralis major and minor muscles and inferior portion of the serratus anterior muscle. Their main function is to provide another functional connection between the thorax and upper limb and neck and through that, to assist movements of the shoulder (pectoral) girdle.
On this page you can find quizzes on muscles that act on the chest, using interactive animations and diagrams. Learn everything you need to know about this topic with comprehensive anatomy videos taught by experts.
Pectoralis Major Muscle – Attachment, Action & Innervation
Pectoralis major is a thick, fan-shaped muscle contributing to the thoracobrachial motion. It consists of a clavicular part and a sternal part, both converging to a flat tendon that inserts on the humerus. It’s innervated by both medial and lateral pectoral nerves.
Pectoralis Minor Muscle – Attachment, Action & Innervation
Pectoralis Minor Muscle (Insertion, Origin, Actions & Innervations); explained beautifully in an illustrated and interactive way.
Serratus Anterior Muscle
Serratus Anterior Muscle (Insertion, Origin, Actions & Innervations); explained beautifully in an illustrated and interactive way.
External Intercostal Muscles
External Intercostal Muscles (Insertion, Origin, Actions & Innervations); explained beautifully in an illustrated and interactive way.