Question

Do you feel some hard bumps on the back? What are they called?

Answer 1

Generally, human body can experience different kinds of bumps and lumps which can be the result of various deformities in the body or on the skin.

However, when you touch your back you can feel a hard bump, which is called spinal; cord.

Spinal cords is one of the major parts of our body which is made of support cells and bunch of nerves and it stretches from medulla oblongata of the brain to lumbar region. 

Answer 2

The hard bumps on the back are the spinal cord. Here are some interesting facts about spinal cord :

The spinal cord is covered by three protective membranes known as meninges. The space between the layers of meninges is filled with a fluid known as cerebrospinal fluid. It is clear and colourless liquid that protects the spinal cord.

Giraffes and humans have the same number of vertebrae in their spinal cord.

The spinal column consists of roughly 220 individual ligaments.

That's all, thanks....