The largest artery in the human body, intimately connected to the heart, aorta is usually regarded as the major source of oxygenated blood for the circulatory system. The three concentric layers, which surround the aortic lumen-the tunics intima, media and adventitia, transform the aorta in a large elastic duct, which is irregular calibrated according to its segments. The special aortic distensibility is facilitated by its elastic circumferential lamellar complex. Any disturbance of its structural components is able to interfere with its normal and vital activity. Our study intends to reveal that the development of elastic lamellae should be regarded not only as an indispensable step for the aortic wall configuration, but also like a process in a firm connection with the rest of aortic wall components. The transition from intrauterine life to a new stage of life, childhood, has to determine an adequate adaptation of almost all the components of aortic wall, in order to sustain a consistent pulsatile blood flow. Stereological quantitative analysis of thoracic aortic fragments prelevated from newborns and children was performed in order to estimate the dynamic of vascular wall increase. We first estimated the general configuration of the thoracic aortic wall, quantifying the principal constituents; the connective tissue profile, investigated through its main elements, collagen and elastic fibers, supports the idea that each type of fiber has a distinct evolution in different groups of ages and has to be correlated with their involvement in maintaining of the aortic wall mechanical properties. Elastic fibers percentage volume was increased in both examined groups, with a small difference reported in children aorta, while collagen fibers exhibit a slow increase in children aorta. Our morphometric quantitative assessment suggests that further studies have to draw of in a precisely manner the outline of the secretory well defined function of vascular smooth muscle cells; the elucidation of the manner in which the secretory pathway for each type of fiber becomes fully adapted to every stage of aortic development will allow a new perspective in aortic pathology.