Question

What is the function of intervertebral discs? What are they made of?

Answer 1

Hint: The intervertebral discs have some vascular supply during infancy. They have almost no blood supply in an adult. The size of the intervertebral discs can be altered due to some pathological conditions like discitis.

Complete answer:
An intervertebral disc is located between the adjacent vertebrae in the vertebral column. The discs form a symphysis which allows slight vertebral movement. A symphysis is a fibrocartilaginous joint between two bones. It acts as a ligament which holds the vertebrae together.
The primary function of the intervertebral discs is to provide the appropriate surface required for the shock absorbing gel by separating the vertebrae. The nucleus pulposus of the intervertebral discs distributes the pressure created under compressive loads under all directions.
The intervertebral discs are made up of an external fibrous ring called the annulus fibrosus. The external fibrous ring is surrounded by an internal gel-like core called the nucleus pulposus. The outer annulus fibrosus is made up of several concentric layers of fibrocartilage. This fibrocartilage is made up of both Type 1 and Type 2 collagen.
The nucleus pulposus helps dissipate pressure on the vertebrae by distributing pressure evenly across the vertebrae. This prevents the damage caused by stress conditions to the vertebrae situated below.
Each pair of vertebrae has an intervertebral disc in between except the atlas, which is the first cervical vertebra.

Note:
A slipped disc can happen when there is an unbalanced pressure which causes the deformation of the annulus fibrosus. It is accompanied with poor posture.
Twenty five percent of the population shows a degeneration in the size of the intervertebral disc by the age of 40.