FIGURE 1-11 Body Cavities. (a) The dorsal body cavity is bounded by the bones of the skull and vertebral column. The muscular diaphragm divides the ventral body cavity into a superior thoracic (chest) cavity and an inferior abdominopelvic cavity.he Thoracic Cavity The walls of the thoracic cavity surround the lungs and heart; associated organs of the respiratory, cardiovascular, and lymphatic systems; the inferior portions of the esophagus; and the thymus.
Half marathon. A half marathon is a road running event of 21.0975 kilometres (13.1094 mi) â half the distance of a marathon. Participation in half marathons has grown steadily since 2003, partly due to the fact that it is a challenging distance, but does not require the same level of training that a marathon does.
1 Since 2003, the half-marathon has been the fastest growing road race distance in the United State s, and for seven consecutive years (2006-12), the number of 13.1 mile finishers has grown by 10% or more each year. 2  No other U.S. road distance comes close to this growth rate during the Second Running Boom (circa 1994).