The Human Nervous system

-Karthik Gurumurthy

Vertebrates and other complex animals have a nervous system controlled by a brain, a gray, wrinkly organ made up millions of neurons. The brain connects to a vast network of nerves and other organs that coordinate the body’s activities.

You could not survive without your brain. It processes information and directs the body’s actions. It tells the heart to beat, lungs to breathe, and muscles to move. It reacts to information from the world outside through your ears, eyes, nose, mouth and skin. It also controls the homeostasis of your body.

Here is how the human nervous system works: The spinal cord, a thick bundle of nerves running down your back, links your brain to the rest of your body. The brain and spinal cord use two kinds of neurons to communicate with the body. Sensory neurons gather information from all parts of the body and carry it to the brain and spinal cord. Motor neurons deliver orders from the brain and spinal cord. Motor neurons deliver orders from the brain and spinal cord telling the body what to do and how to respond to information provided by the sensory neurons.

Different regions of the brain control specific activities in the body. Hearing, seeing, smelling, tasting, and talking, are each controlled by separate regions. One area coordinates your movements. Another controls your emotions- you cry when this area directs your body to create tears. You laugh when it creates a special brain chemical to make you feel happy.

Certain regions of your brain are unconscious- that is, they are always on “autopilot.” They direct activities on your body such as breathing, digestion, and creating new cells, without any thought from you. Learning, memory and thinking are controlled by conscious parts of your brain.