Transversus abdominis muscle

Beginning:


 * cartilage 7.–12. ribs;
 * edges of thoracolumbar fascia;
 * iliac crest;
 * inguinal ligament.

Insertion:


 * linea alba (through the aponeurosis);
 * the lower edge merges with the aponeurosis of musculus obliquus internus and thus forms the falx inguinalis;
 * the caudal edge of the aponeurosis passes into the ligamentum interfoveolare (part of the  inguinal canal).

Innervation:


 * intercostal nerves (7.–11.);
 * subcostal nerve;
 * iliohypogastric nerve;
 * ilioinguinal nerve;
 * genitofemoral nerve.

Function:


 * participates in the abdominal press;
 * expiratory accessory muscle;
 * regulation of tension in the inguinal canal.

Formations on the obluquus externus abdominis muscle:


 * aponeurosis musculi transversi: the tendon into which the muscle passes towards the rectus abdominis muscle.