Serratus Posterior Superior - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The serratus posterior superior is a muscle within the intermediate compartment of the back. It is a thin and rectangular in shape, and lies deep to the rhomboid muscles in the upper back. Attachments: Originates from the lower part of the ligamentum nuchae, and the cervical and thoracic spines (usually C7 – T3). The muscle fibres run in an inferolateral direction, attaching to ribs 2 – 5. Actions: Elevates ribs 2 – 5. Innervation: Intercostal nerves T2 – T5. Blood Supply: Posterior intercostal arteries. Adobe Stock, Licensed to TeachMeSeries Ltd Fig 1The intermediate back muscles; serratus posterior superior and inferior. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Frequent questions What is the serratus posterior superior muscle? The serratus posterior superior is a thin, rectangular muscle located in the intermediate compartment of the back, situated deep to the rhomboid muscles. It plays a role in elevating the upper ribs during respiration. Where does the serratus posterior superior muscle originate? This muscle originates from the lower part of the ligamentum nuchae and the spines of the cervical and thoracic vertebrae, specifically from C7 to T3. Its strategic position aids in its function of rib elevation. What are the attachments of the serratus posterior superior muscle? The serratus posterior superior attaches to the ribs 2 through 5, with its muscle fibres running in an inferolateral direction. This arrangement allows it to effectively elevate the associated ribs. What is the primary action of the serratus posterior superior? The main action of the serratus posterior superior is to elevate ribs 2 to 5 during inhalation. This elevation assists in expanding the thoracic cavity for improved respiratory function. How is the serratus posterior superior muscle innervated? The serratus posterior superior receives its nerve supply from the intercostal nerves T2 to T5. This innervation is crucial for its role in rib elevation and respiratory mechanics. Rate This Article