Tuesday, December 1, 2009
at
10:39 AM
|
0
comments
The nervous system is always buzzing around It buzzes with messages that run to and from all the parts of your body. Every second, hundreds of these messages make their journey through the body. The messages are carried by strings of totally original cells called neurons, or nerve cells. Neurons are the basic things that make up the nervous system. Neurons are like unique pieces of art because, unlike other cells in your body, they can’t be replaced. No worries. You’re born with enough to last your whole life. Neurons come in all shapes and sizes, but they have some stuff in common. The big part of the neurons is called the cell body. The cell body has the nucleus the circle in the middle, which tells the rest of the cell what to do.
You can think about the cell body being kind of like a switchboard for the Mega-fast messages sending neuron. Running into the nucleus are tiny little things that look like tree branches called dendrites. The dendrites carry messages to the cell body of a neuron. The thing that looks like a long tail is called an axon, it carries messages away From the cell body. Each neuron only has one axon, but the axon can be From 1 millimeter to more then 1 meter in length Did you see that at the bottom of the neuron it looks like the axon splits into spaghetti strings? These spaghetti strings are called axon terminals ends. Axon terminals forward messages to the dendrites of other neurons like forwarding an email to a new person. Axon terminals are usually quite a ways away From the cell body. There are three types of neurons in your nervous system – sensory neurons, interneurons, and motor neurons. To find out how they work, try This Press your Finger against your desk. What happens? You feel the Pressure of the desk pushing into your skin. It might even hurt, if you Press hard enough. Before long, you more your finger. How do neurons let you do all this? Special cells called receptors get information from around you. In this activity the receptors are in your finger. Messages travel from these receptors to your spinal cord and brain through sensory neurons. Your spinal cord and brain have interneurons. Interneurons connect sensory neurons to motor neurons. It is through motor neurons that the messages from your brain and spinal cord are sent to a muscle cell or gland cell in your body. The muscle cell or gland cell that responds to the motor neuron is called an effector.
Posted by
laura
