The brain, and how it works Essay

Submitted By Weston-Martin
Words: 504
Pages: 3

During this essay, I will be defining the process of nerve impulses. To begin with, the definition of nerve impulses is a progressive wave of electric and chemical activity along a nerve fiber that stimulates or inhibits the action of a muscle, gland, or other nerve cell. If that didn’t help, in easier words, electrical waves that go from the brain, travel through the nerves, and go to places and tell them what to do. First, we start with the brain. This is an extremely broad topic, so I will just basically outline it. The brain is a 3 pound hunk of tissue. That might not seem like much, but it holds the power to create the things that you like, don’t like, your personality, and your thoughts. This is all achieved through nerve impulses. Electric waves, like I have said before, have different frequencies and sequences to tell who to do what. Secondly, we decide, how do the waves travel through the body? They couldn’t just spread through blood, like electricity does through water, can it? No, they can’t go through blood, actually. They simply travel through the spine, which branches off into nerves, which spread to all parts of the body. They work like a relay system; the brain sends a nerve impulse down the spine, which gives the signal off to a nerve, which travels to say, the knee, and tells it to bend. This process takes just under half a second to take place. Next, well, we’ll discuss how fast they are. Action potentials can travel along axons at speeds of 0.1-100 m/s. This means that nerve impulses can get from one part of a body to another in a few milliseconds, which allows for fast responses to stimuli. (Impulses are much slower than electrical currents in wires, which travel at close to the speed of light, 3x108 m/s.) The speed is affected by 3 factors:
Temperature - The higher the temperature, the faster the speed. So, warm-blooded animals have faster