Respiratory muscles

The respiratory muscles are those skeletal muscles that lead to an expansion or narrowing of the chest and thus to inhalation or exhalation . The most important respiratory muscle is the diaphragm ( diaphragm ), further including the intercostal muscles and lower intercostal muscles and the accessory respiratory muscles to respiratory muscles. The muscles that come into action depend heavily on the breathing technique ( chest breathing or abdominal breathing ).

In normal breathing, the muscles only play a role for inspiration (inhalation). This requires an expansion of the chest, which is achieved by so-called inspiratory muscles ("inspirators"). They create an increased negative pressure in the pleural space and thus an expansion of the lungs , whereby air is sucked in. Exhalation, on the other hand, is mostly passive by slackening these muscles. Due to the elastic fibers in the lung tissue, it contracts and presses the air out of the lungs. Only with increased breathing or with lung diseases must the exhalation also be supported by auxiliary muscles ( expiratory muscles , "expirators").

Inspiratory muscles (inhalation)

• Diaphragm ( diaphragm )
• Musculi external intercostal (outer intercostal muscles )
• Musculi intercartilaginei, i.e. the part of the inner intercostal muscles that runs between the costal cartilages

Auxiliary inspiratory muscles (inhalation)

• Levatores costarum muscles
• Scalen muscles
• Serratus anterior muscle (anterior saw muscle)
• Serratus posterior superior muscle (posterior superior saw muscle)
• Serratus posterior inferior muscle (posterior lower saw muscle)
• Musculus pectoralis minor et major (with arm propped up)
• Sternocleidomastoid muscle
• Erector spinae muscle

Expiratory muscles (exhalation)

• Musculi intercostales interni et intimi (inner intercostal muscles )
• Subcostal muscles (lower rib muscles)

Auxiliary expiratory muscles (exhalation)

The expiratory auxiliary breathing muscles support exhalation ( auxiliary breathing ):

• External obliquus abdominis muscle
• Internus abdominis oblique muscle
• Transversus abdominis muscle
• Transversus thoracis muscle
• Musculus latissimus dorsi ("cough muscle")
• ( Retractor costae muscle (not created in humans))
• Quadratus lumborum muscle
• Rectus abdominis muscle

literature

• Gerhard Aumüller et al .: Dual series. Anatomy. 2nd, revised edition. Georg Thieme, Stuttgart 2010, ISBN 978-3-13-136042-7 .
• Peter Lotz: Anatomy and Physiology of the Respiratory Tract. In: J. Kilian, H. Benzer, FW Ahnefeld (ed.): Basic principles of ventilation. Springer, Berlin a. a. 1991, ISBN 3-540-53078-9 , 2nd, unchanged edition, ibid 1994, ISBN 3-540-57904-3 , pp. 3–45; here: p. 14.