FUNCTION OF THE SPINAL CORD

The Spinal cord is an extension of the brain. Messages from the different parts of the body travel through it to the brain and back. The nerves in the spinal cord carry these messages to and from your brain.

The spinal cord enables us to do things automatically. This automatic action is called reflex action. For instance, when you touch a hot object such as flat iron, you immediately withdraw your hand. This action does not involve your brain because you do not think at all whether you avoid the hot object or not.

In a reflex action, the nerve impulses take a special pathway called reflex arc.

In the case of your touching the flat iron, the impulse moved from the skin (sensory nerve) where it came into contact with flat iron to your spinal cord.Here, the impulses set off another impulse in a motor nerve running from your spinal cord to your arm muscles. The muscles contracted and pulled your hand away from the flat iron. This action took place less than 1/50 of a second. At the same time, the original impulse traveled up to your spinal cord to your brain, where you feel it as pain.

A reflex is a rapid automatic response to the environment that happened without action of the brain. They can be a movement, as in motor reflex. Blinking when suddenly comes too close to the eyes is a motor reflex. Other reflex action can be develop through memory. The brain remembers how to respond to certain signals or situations. This is called a conditioned reflex. A conditioned reflex is based upon previous experience. For example, hearing to an ice cream van might make someone’s mouth water. This is a conditioned reflex.

Another example is seeing and smelling food you like most. Before you actually put the food in your mouth, you see it and smell it. You associate its appearance and odor with its taste. As a result, when you see and smells foods that you like, even though you do not actually taste it, saliva is secreted and your mouth will water. In this case, the secretion represents a conditioned reflex. Conditioned reflexes vary from one individual to another.

Reflex actions are very useful. They protect you from harm. Blinking is a reflex that help your eyes from objects flying the air toward your face. Sneezing and coughing are reflexes that help to remove objects from your throat and air passages. The automatic action of your reflexes usually causes you to act correctly and quickly enough to avoid the danger threatening you.