Question
Question: In human adults, vertebral column 33 bones. How much does a human contain prior to adolescence? A....
In human adults, vertebral column 33 bones. How much does a human contain prior to adolescence?
A. 33
B. 29
C. 27
D. 26
Solution
Based on different skeletal structures present in the body of the organism, endoskeleton is divided into two principal division:-
Axial skeleton: It runs along the middle longitudinal axis of the body. It comprises 80 bones which distribute along the main axis and form four structures such as the skull, vertebral column, sternum and ribs.
Appendicular skeleton: It includes the skeleton of the limbs, the pectoral and pelvic girdle which supports and suspends the skeleton of limbs from the vertebral column.
Complete answer:
Let us first know about the vertebral column.
The vertebral column is also known as the backbone. It lies in the mid-dorsal region of the neck and trunk and is made up of 26 serially arranged units called vertebrae. In other words, the vertebral column extends from the base of the skull and constitutes the main framework of the trunk. Between two adjacent vertebrae, a disc or pad of fibrous cartilage is present which provide flexibility to the vertebral column. The pads of fibrous cartilage present between the vertebrae are called an intervertebral disc.
Vertebral column protects the spinal cord, supports the head and serves as the point of attachment for the ribs and musculature of the back.
| Vertebrae Type | Foetal Stage | Adult |
|---|---|---|
| Cervical | 7 | 7 |
| Thoracic | 12 | 12 |
| lumbar | 5 | 5 |
| sacral | 5 | 1 |
| coccyx | 4 | 1 |
| 33 | 26 |
The vertebral column contains 26 bones prior to adolescence.
Hence, the correct answer is option (D).
Additional information:
The curvature of the Vertebral Column: Looked at from the side, the vertebral column presented four anteroposterior curves: the cervical curve in the neck which is convex forwards, the thoracic curve, convex backwards, the lumbar curve, convex forwards, and the pelvic curve, convex backwards.
Note: Sacral vertebrae: The sacral vertebrae fuse to form a triangular bony complex or structure called the sacrum. It is present in the pelvic region. The female sacrum is wider and shorter than the male sacrum.
Coccyx: The four or five coccygeal bones unite together to form a small vestigial tail bone called the coccyx. It is attached to the base of the sacrum.