Final answer:
Humans possess seven cervical vertebrae, which support the head and allow for various head movements. The cervical vertebrae are numbered C1 to C7 and form the topmost part of the vertebral column.
Step-by-step explanation:
Humans possess seven cervical vertebrae. The correct answer is (C) 7.
The human vertebral column, an essential part of the skeleton, is structured into several regions. It consists of 33 vertebrae at birth, which later reduces to 24 vertebrae in the adult, plus the sacrum and coccyx due to the fusion of some vertebrae. Specifically, the neck region contains seven cervical vertebrae, designated C1 to C7. These vertebral bones support the head and allow for a range of movements. In the thoracic region, there are twelve vertebrae (T1-T12), which connect to the ribs and form the middle portion of the spinal column. The lower back comprises five lumbar vertebrae (L1-L5). Furthermore, the os sacrum is a single bone formed from the fusion of five sacral vertebrae, and the coccyx results from the fused four coccygeal vertebrae. These structures develop over time, with the sacral and coccygeal fusions completing typically by middle age. The vertebral column's curvatures contribute to its strength and flexibility, enabling it to absorb shocks and protect the spinal cord.