Serratus posterior superior muscle

Posterior superior serratus muscle

Serratus Posterior Superior Muscle is a thin, quadrilateral muscle located in the upper back, part of the human anatomy that plays a role in the respiratory system. It arises from the nuchal ligament and the spinous processes of the C7 to T3 vertebrae, and extends laterally to attach to the upper borders of the 2nd to 5th ribs. This muscle is involved in the elevation of the upper ribs, aiding in the process of inhalation.

Structure

The Serratus Posterior Superior Muscle is situated deep to the rhomboid muscles and the trapezius but superficial to the erector spinae. It is part of the extrinsic muscles of the back, which are primarily involved in the movements of the appendicular skeleton. The muscle fibers run obliquely downward and laterally, inserting into the rib cage.

Function

The primary function of the Serratus Posterior Superior is to assist in the breathing process. By elevating the 2nd to 5th ribs, it increases the volume of the thoracic cavity during forced inhalation. However, its role in respiration is considered minor compared to the diaphragm, intercostal muscles, and other primary respiratory muscles.

Innervation

The Serratus Posterior Superior is innervated by the intercostal nerves, specifically the second to fifth intercostal nerves. These nerves provide the sensory and motor innervation necessary for the muscle's function.

Clinical Significance

While injuries or conditions directly affecting the Serratus Posterior Superior are rare, its relevance comes into play in the context of upper back pain and respiratory issues. Understanding its location and function can aid in the diagnosis and treatment of certain conditions affecting the upper back and thoracic region.

See Also

• Muscular System
• Respiratory System
• Thoracic Vertebrae
• Ribs (anatomy)