The serratus posterior inferior muscle, also known as the posterior serratus muscle, is a

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

of the

human body The human body is the entire structure of a Human, human being. It is composed of many different types of Cell (biology), cells that together create Tissue (biology), tissues and subsequently Organ (biology), organs and then Organ system, org ...

Structure

The muscle is situated at the junction of the thoracic and lumbar regions. It has an irregularly quadrilateral form, broader than the serratus posterior superior muscle, and separated from it by a wide interval. It arises by a thin aponeurosis from the spinous processes of the lower two thoracic and upper two or three lumbar vertebrae. Passing obliquely upward and lateralward, it becomes fleshy, and divides into four flat digitations. These are inserted into the inferior borders of the lower four ribs, a little beyond their angles. The thin aponeurosis of origin is intimately blended with the thoracolumbar fascia, and aponeurosis of the latissimus dorsi muscle.

Function

The serratus posterior inferior draws the lower ribs backward and downward to assist in rotation and extension of the trunk. This movement of the ribs may also contribute to inhalation and forced expiration of air from the

lung The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...

Additional images

References

External links

* - "Intermediate layer of the extrinsic muscles of the back, deep muscles." * {{Authority control Muscles of the torso

Structure

Function

Additional images

See also

References

External links