Question

Number of lumbar vertebrae in the human skeleton is
A. 12
B. 7
C. 5
D. 2

Answer 1

Hint: The human skeleton consists of 206 bones of which 33 comprises the human vertebral column. The vertebral column is divided into five segments namely, cervical part, the thoracic vertebra, the lumbar vertebrae, the sacrum and the coccyx. The sacrum is a combination of five bones, which fuse into a single bone with advancement of age. Similarly, the coccyx is a set of four bones which fuse into a single coccyx bone.

Complete answer: The adult vertebral column consists of 26 vertebrae bones but a child has 33 vertebrae in the backbone. The decrease in number is due to the fusion of sacrum and coccyx into a single bone in adults.
The lumbar vertebrae form the bones of the lower back. The lumbar vertebrae represents the third part in the spinal cord, located between the thorax and sacrum. The number of vertebrae in each part is given as below:
-Cervical – 7
-Thoracic -12
-Lumbar – 5
-Sacrum- 5
-Coccyx- 4
The five lumbar vertebrae are named from L1 to L5. They remain unfused during the entire lifetime. Unlike sacrum and coccyx, the lumbar vertebrae do not fuse into a single bone. The lumbar vertebrae are the largest of all the vertebral bones. They are meant to absorb the stress while doing heavy work and lifting heavy objects.
The correct answer is Option (C) 5.

Note: The lumbar part of the vertebral column is sensitive because the CSF during lumbar puncture is drawn from the area between L2 and L3 vertebrae. The body of each lumbar vertebrae is kidney shaped. The lumbar vertebrae allows the bending and twisting movement of the back.