Final answer:
The Curve of Spee begins anteriorly and follows the concave curvatures of the thoracic and sacrococcygeal regions, from anterior to posterior.
Step-by-step explanation:
The Curve of Spee begins anteriorly and follows the concave curvatures of the thoracic and sacrococcygeal regions, from anterior to posterior. During fetal development, the body is flexed anteriorly into the fetal position, giving the entire vertebral column a single curvature that is concave anteriorly. In the adult, this fetal curvature is retained in two regions of the vertebral column as the thoracic curve, which involves the thoracic vertebrae, and the sacrococcygeal curve, formed by the sacrum and coccyx. Each of these is called a primary curve because they are retained from the original fetal curvature of the vertebral column.