Which of these vertebrae is of the same number in man and rabbit?

Analyze the question: We need the type of vertebrae whose number is the same in humans and rabbits.

Concept: Almost all mammals, including humans and rabbits, have 7 cervical vertebrae in the neck. This holds even for giraffes, whales and bats. The numbers in the other regions vary from one species to another.

Vertebral formula comparison:

| Region | Man | Rabbit | |---|---|---| | Cervical | 7 | 7 | | Thoracic | 12 | 12 (sometimes 12-13) | | Lumbar | 5 | 7 | | Sacral | 5 (fused) | 4 (fused) | | Caudal | 4 (fused coccyx) | about 15-16 |

Working through the options:

• A. Caudal: Man has a short coccyx of about 4 fused bones, while the rabbit has a tail of about 15 or more. Not the same.
• B. Cervical: Both have 7. Same.
• C. Lumbar: Man has 5 and the rabbit has 7. Not the same.
• D. Sacral: Man has 5 and the rabbit has about 4. Not the same.
• E. Thoracic: Man has 12 and the rabbit usually has 12 or 13. Some textbooks give 12 for both, but the count varies in rabbits, so it is not the reliable answer.

Conclusion: The cervical count of 7 is the constant that is always the same in both.

Exam tip: Remember "all mammals have 7 neck bones". Whenever a question asks which vertebrae are the same across mammals, think cervical first.