<prompt> In evaluating a breast lesion in a female athlete, the surgeon notes that the tumor is in the anterior axillary line. To which site does the lateral edge of normal breast tissue extend?The lateral edge of the pectoralis major muscleThe medial edge of the pectoralis minor muscleCover the medial third of the serratus anterior muscleThe semispinalis capitis  <response>: The breast tissue extends over the medial margin of the serratus anterior muscle. The nerve to the serratus anterior lies on the lateral aspect of this muscle and may be accidentally injured during breast surgery. 