The serratus posterior superior and inferior muscles lie deep on the front part of the neck. The serratus posterior superior is a thin, flat, quadrilateral muscle that extends from the neck to the third, fourth, and fifth |ribs|. The |serratus posterior inferior| is broader than the serratus posterior superior and extends to the four lower |ribs|. Both muscles are respiratory muscle. The serratus posterior superior elevates the |ribs| as you inhale and the |serratus posterior inferior| pulls the |ribs| down and back to exhale.
