The cutaneous muscle of the trunk (Musculus cutaneus trunci) covers the lateral part of the trunk, caudal to shoulder and arm. It forms the fold of the flank and dips medial to arm with the deep pectoral muscle.
Origin: Superficial gluteal fascia.
Insertion: Axilla and on caudal border of deep pectoral muscle.
Action: Shakes the skin to remove foreign bodies and increase heat production. It also tenses the skin when required. The preputial muscle draws the prepuce over the glans after erection. The supramammary muscle aids in support of the mammary glands and perhaps in milk ejection.
Nerve: Efferent supply, lateral thoracic nerve, afferent supply, lateral thoracic and lateral branches of the intercostal nerves and the costoabdominalis, iliohypogastricus, ilioinguinlalis and genitofemorilis.