Vertebral column (Latin)

Columna vertebralis seen from the anterior perspective. The individual vertebrae of each of the 5 regions are labelled. Each vertebra is named in numerical order within their region from superior to inferior. The first region, the columna vertebralis cervicalis, consists of 7 vertebrae. The first (C1) and second (C2) vertebrae are unique in their anatomical appearance and are named atlas and axis, respectively. The seventh cervical vertebra (C7) is also known as the vertebra prominens. The second segment, the columna vertebralis thoracis, is the longest portion of the columna vertebralis and comprises 12 vertebrae, which house the heads of the ribs (capita costarum). Moving inferiorly, there is a shorter region called the columna vertebralis lumbalis. This region consists of 5 vertebrae. The most inferior portion of the spine consists of two bones (os sacrum and os coccygis) composed of fused vertebral bodies (corpora vertebrae). The os sacrum comprises 5 vertebrae, while the os coccygis can have a variable number of vertebrae (usually 3 to 5).When observed from the lateral aspect, the columna vertebralis presents four curvatures: two concavities and two convexities. The curvatures that are concave anteriorly are called the kyphoses thoracica et sacralis. The curvatures that are convex anteriorly are known as the lordoses cervicalis et lumbalis.