In beginning of this dissection, it is assumed that the pectoralis major and pectoralis minor muscles have been studied ( see Laboratory Four). Reflect both muscles laterally and superiorly , and identify the following skeletal landmarks of the anterior thoracic wall:
As the skin is reflected laterally from the lower anterior thoracic wall, other muscles may be seen, e.g. serratus anterior muscle, external abdominal oblique muscle, and rectus abdominis muscle.
Links and References: