serratus posterior superior muscle
Anatomical term for a thin, quadrilateral muscle in the upper back that elevates the ribs during inspiration.
The serratus posterior superior muscle is involved in elevating the second to fifth ribs.
The term is composed of 上 (upper), 後 (posterior), 鋸 (saw, referring to the serrated appearance), and 筋 (muscle), following standard anatomical naming conventions.