Final answer:
b. Consists of 33 vertebrae
The vertebral column, or spine, is a key structure in the human body, providing support, protection for the spinal cord, and facilitating movement. It consists of 33 vertebrae in total, which include 7 cervical, 12 thoracic, 5 lumbar, the sacrum, and the coccyx, with the latter two being fused structures in adults.
Step-by-step explanation:
Vertebral Column
The vertebral column, also known as the spine or spinal column, is a complex structure that plays a crucial role in the human body. It provides support for the body and protection for the spinal cord. The vertebral column is composed of a sequence of 33 vertebrae at birth, which includes individual bones in the cervical, thoracic, and lumbar regions, as well as bones that are fused together in the sacral and coccygeal regions. In adults, this number becomes 26, as the sacrum (composed of five fused vertebrae) and the coccyx (composed of three to four fused vertebrae) are counted as single bones. The spine is divided into different regions: there are 7 cervical vertebrae (C1-C7), 12 thoracic vertebrae (T1-T12), 5 lumbar vertebrae (L1-L5), the sacrum, and the coccyx. This structure provides the flexibility necessary for movement and acts as an attachment point for ribs and muscles of the back and neck.