Vertebral Formula of Humans

The vertebral formula refers to the number and type of vertebrae present in the human spine. It provides a standardized way of describing the arrangement of vertebrae in different regions of the spine. The correct vertebral formula for humans is option 'D': C7T12L5S(5)C(4).

Here is a breakdown of the vertebral formula and an explanation of each component:

1. C7: This indicates that there are 7 cervical vertebrae in the human spine. The cervical vertebrae are located in the neck region and are numbered from C1 to C7.

2. T12: This indicates that there are 12 thoracic vertebrae in the human spine. The thoracic vertebrae are located in the upper back region and are numbered from T1 to T12. These vertebrae are associated with the ribs.

3. L5: This indicates that there are 5 lumbar vertebrae in the human spine. The lumbar vertebrae are located in the lower back region and are numbered from L1 to L5. These vertebrae are the largest and support the weight of the upper body.

4. S(5): This indicates that there are 5 sacral vertebrae in the human spine. The sacral vertebrae are fused together to form the sacrum, which is a triangular bone located between the hip bones. The sacrum provides stability to the pelvis.

5. C(4): This indicates that there are 4 coccygeal vertebrae in the human spine. The coccygeal vertebrae are also fused together to form the coccyx, commonly known as the tailbone. The coccyx is a vestigial structure with no specific function in humans.

Therefore, the vertebral formula 'C7T12L5S(5)C(4)' accurately represents the arrangement of vertebrae in the human spine.

Conclusion:
The correct vertebral formula for humans is 'C7T12L5S(5)C(4)'. This formula indicates that humans have 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal vertebrae. Understanding the vertebral formula helps in accurately describing the anatomical structure and function of the human spine.