Do all messages from the body travels to the brain through the spinal cord?

Answer 1

The nerves, spinal cord and brain work together to keep you aware of what's going on with the body and get messages out to the muscles and other body systems. Not all nerve messages are handled by the brain though and so not all involve the spinal cord, the main path way to the brain from the body's nerves. In addition there are some other routes for information to get to the brain.

Some areas of the body are under "local control" and do not require brain commands or the use of the spinal cord. This would include the involuntary muscles ( e.g. you don't have to think Beat ... beat ... beat at your heart all day) and glands which secrete hormones and enzymes in response to chemical conditions in the body (e.g. no brain commands go to the pancreas)

Some nerve responses only go as far as the spinal cord and then are bounced back to the originating area without the brain's input. An example, if you prick your finger the pain input is bounced back to the arm muscles to pull your finger away without the brain's input. A secondary message goes to the brain to notify it of the pain.

A lot of the body nerve input does go through the spinal cord. Muscle position information, pain messages, pressure, heat. A lot of the messages from the brain follow the return route (muscle movement)

There are however some nerve impulses which get hard wired directly into the brain. As an example the eyes contain the optic nerves which are essentially brain tissue poking through the front of your face. This results from the need to have almost instantaneous awareness of what is going on visually. Routing nerve messages through the spinal cord would take too long and the lateness of the information would make hunting (like a bird chasing flying insects) or jumping from limb to limb (as a monkey does) impossible.