subcostal muscle

Introduction

One of a number of inconsistent muscles of the posterolateral abdominal wall, having the same direction as the internal intercostal muscles, but extending across (deep to) one or more ribs, inserting on a rib 2 or 3 ribs below.

Origin

• internal surface of lower border of superior (upper) rib

Insertion

• obliquely, down & forward to upper border of 2nd or 3rd inferior (lower) rib

Action

elevates ribs

Innervation

intercostal nerve

More general terms

• skeletal muscle (voluntary muscle)