The boundaries of the tho-racic outlet are:

The boundaries of the tho-racic outlet are:

a. Posterior the body of the seventh thoracic vertebra
b. Posterior the body of the twelfth thoracic vertebra
c. Anterior the xifoid process of the sternum
d. Anterior and lateral the joined cartilage of the seventh to twelve ribs
e. Lateral the medial surface of the seventh rib