Question

Which of the following statements are correct with reference to human endoskeleton?
A. Human skull is monocondylic.
B. The joint between any two adjoining vertebrae is a cartilaginous joint.
C. In human beings, the number of cervical vertebrae is seven.
D. All ribs except the last 2 pairs are bicephalic.
E. The occipital bone of skull is articulated with atlas vertebra.
Choose the correct answer from the options given below:

• A. B, C and E only
• B. C, D and E only
• C. A, B and D only
• D. B and E only

Hint:

Logic Tip: Mammals and Amphibians have "Di-condylic" skulls (2 condyles). Reptiles and Aves (Birds) have "Mono-condylic" skulls (1 condyle). Knowing Statement A is false instantly rules out Option 3!

Answer 1

The Correct Option is A

Step 1 : Understanding the Question:
The objective is to identify the factually correct anatomical features of the human axial skeleton. We must evaluate statements regarding the number of vertebrae, the types of joints between vertebrae, the nature of the skull's articulation with the spine, and the structural morphology of the ribs.
Step 2 : Key Formulas and Approach:
The approach involves cross-referencing cadaveric anatomy and standard physiological texts regarding the skeletal system:
1. Cranial Articulation: Identifying the number of occipital condyles at the base of the skull.
2. Joint Classification: Categorizing the movement and tissue of intervertebral joints (Fibrous vs. Cartilaginous vs. Synovial).
3. Vertebral Constants: Identifying the specific number of cervical vertebrae, which is a mammalian characteristic.
4. Rib Anatomy: Understanding the dorsal attachment points to the vertebral column.
5. Cervical-Cranial interaction: Identifying the first vertebra and its role.
Step 3 : Detailed Explanation:

Statement A: The human skull articulates with the vertebral column via two occipital condyles. This configuration is known as dicondylic. Monocondylic skulls (one condyle) are characteristic of reptiles and birds. Therefore, this statement is incorrect.

Statement B: Adjoining vertebrae in the spinal column are held together by intervertebral discs made of fibrocartilage. These joints allow for limited movement and serve as shock absorbers. Because they use cartilage as the connecting medium, they are classified as cartilaginous joints. This statement is correct.

Statement C: A defining feature of nearly all mammals, including humans, is the presence of seven cervical vertebrae in the neck region. This number remains constant regardless of the length of the neck. This statement is correct.

Statement D: Each human rib is technically bicephalic because it possesses two articulation surfaces on its dorsal end for attachment to the vertebrae. This structural trait applies to all ribs, not just the first ten pairs. The phrasing that excludes the last 2 pairs makes the statement factually inaccurate in a general anatomical sense.

Statement E: The occipital bone at the base of the skull features two condyles that sit directly into the superior articular facets of the first cervical vertebra, which is the Atlas (C1). This articulation allows for the nodding motion of the head. This statement is correct.

Step 4 : Final Answer:
Upon detailed evaluation, statements B, C, and E are the only correct descriptions of the human axial skeleton according to standard biological nomenclature. Consequently, the correct option is (A).