 As the fascia leaves the lower edge of the pectoralis major to cross the floor of the axilla it sends a layer upward under cover of the muscle; this lamina splits to envelop the pectoralis minor, at the upper edge of which it is continuous with the coracoclavicular fascia.The hollow of the armpit, seen when the arm is abducted, is produced mainly by the traction of this fascia on the axillary floor, and hence the lamina is sometimes named the "suspensory ligament of the axilla".At the lower part of the thoracic region the deep fascia is well-developed, and is continuous with the fibrous sheaths of the rectus abdominis.