This work has in view the arrangement of the elements that form the anterolateral wall of the neck, thorax and abdomen. We insist on the behavior of the fasciae and the situation of the connective spaces related at the muscular layers that enter the structure of this segments. We have found the continuity of the deep cervical fascia (the superficial fascia, after the French anatomy), like a muff that surrounds the neck and the trunk; in the places where this deep cervical fascia is related to the bones (for example, the clavicle), it is continued by the periosteum. On the ventral midline, the deep cervical fascia is very dense and resistant and it is continued from the hyoid bone to the pubis. It is adherent on the connective deep elements, taking part at the formation of the "linea alba". On the posterior midline it is adherent at the fibrous elements that fix the fascia on the spinous process of the vertebrae. At the level of the neck, this fascia is very obvious and resistant; it becomes thinner according as it descent to the abdomen. At the cervical level it surrounds the sternocleidomastoid and the trapezius, at the level of the thorax it surrounds the pectoralis major and the latissimus dorsi, at the level of the abdomen it becomes very fine and it covers the rectus sheath in the anterior part; at the level of the obliquus externus abdominis is very difficult to demonstrate its existence. We followed then the behavior of the anterolateral muscles from the cervical and the abdominal segments. We have found the continuity of the anterior paramedian muscles: the first plane--the sternocleidomastoid, pectoralis major (its sternal fibres form the right sternal) and the rectus abdominis and pyramidalis. For the first and second planes we make an analogy between the muscles of the neck, the subclavius, pectoralis minor, serratus anterior. The second plane--the infrahyoid muscles, the subclavius, pectoralis minor, serratus anterior. The third plane--the scaleni, anterior, medius and posterior, intercostales, transversus thoracis, obliquus externus abdominis, obliquus internus abdominis and transversus abdominis. This work excludes the suprahyoid muscles--their origin, function, innervation and vascularization are debated in another study.