Question

The intervertebral disc is related to all of the following except
A. To the aorta anteriorly
B. To the ${2^{nd}}$ lumbar nerve closely
C. The cauda equina of the spinal cord
D. Is the site of origin of Psoas major

Answer 1

Intervertebral discs are fibrous cartilages lying between the adjacent vertebrae. They form a fibro cartilaginous joint between the vertebral bodies. It is absent in between the sacrum and coccyx.

Complete answer: Intervertebral discs are the important connecting bodies occurring between the adjacent vertebrae. The shape of these discs is thickest and wedge-shaped located in the lumbar and cervical regions, for protection of highly mobile vertebral columns. It is absent in between the sacrum and coccyx. These discs are composed of an annulus fibrosus and a nucleus pulposus. The other sites of origin of the discs are the anterior surfaces of the medial parts of transverse processes of all the lumbar vertebrae. Slips from tendinous archers in between the adjacent bodies of the lumbar vertebrae, and the psoas major descending in the false pelvis as in to enter the thigh. Since the aorta is predominantly located in the thorax region, the intervertebral disc has no anterior contact with the aorta.
-The nerve supply is by the ventral rami of the upper four lumbar spinal nerves, thus the intervertebral disc is closely related to the second lumbar nerve.
-Cauda equina is a bundle of nerve fibres and spinal nerve rootlets and the intervertebral disc is innervated through the sinuvertebral nerves. Thus there occurs a relation between intervertebral disc with cauda equina.
-Psoas Major is a thick, long, fusiform muscle located in the lumbar region, one site of its origin is through the sides of intervertebral discs and adjoining bodies between twelfth thoracic to fifth lumbar vertebrae.
Thus, option A is the correct answer

Note: The joints present between the individual vertebrae are known as facet joints. The joints are in such a way that they allow a restricted motion but prevent the relapses. The joint is also known as the zygapophyseal joint.