"origin: anterior tubercle of the transverse process of C7"
"insertion: suprapleural membrane; inner border of first rib"
"origin: anterior tubercle of the transverse process of C7"
"insertion: suprapleural membrane; inner border of first rib"
"The scalenus pleuraris muscle (also known as scalenus minimus) is an anatomical variant; a small inconstantly identified ill-defined muscle usually extending from the C7 anterior tubercle to insert into the suprapleural membrane (of Sibson) and the first rib posterior to the groove for the subclavian artery 4. The presence of a scalenus minimus muscle has been well documented but with poor agreement on exact definition with prevalence ranging from 7.8 to 71.7% of cadaveric studies 4-6."
"insertion: suprapleural membrane; inner border of first rib"