Neurons By: Annette Miles

There are about 100 billion neurons in the human brain. Messages, in the form of electrical impulses, constantly travel back and forth between the brain and other parts of the body. A special cell called a neuron is responsible for carrying these messages. There are about 100 billion neurons in the human brain.

A neuron has three main parts A neuron has three main parts. The cell body contains the nucleus and directs all activities of the neuron.

(The cell body or soma contains the nucleus) Label, color, and describe the cell body…(yellow) and the nucleus … (green)! (The cell body or soma contains the nucleus)

Dendrites extend out from the cell body like branches and receive messages from other nerve cells.

Label and describe the job of the dendrites. (Receives Messages)

An axon is a long single fiber that transmits messages from the cell body to the dendrites of other neurons or to other body tissues, such as muscles.

Label, color, and describe the job of the axon…(orange) (Transfers Message)

A protective covering called the myelin sheath, covers most neurons A protective covering called the myelin sheath, covers most neurons. Myelin insulates the axon and helps nerve signals travel faster and farther.

Label, color and describe the job of the myelin sheath…(blue)! (Protects and helps messages send faster and farther)

The space between the axon and the dendrites is called the synapse. Messages travel along a single neuron as electrical impulses, but messages between neurons travel differently. The transfer of information from neuron to neuron takes place through the release of chemical substances into the space between the axon and the dendrites. These chemicals are called neurotransmitters, and the process is called neurotransmission. The space between the axon and the dendrites is called the synapse.

Label, color, and describe the axon terminals… (red)! (Sends Neurotransmitters)

When neurons communicate, an electrical impulse triggers the release of neurotransmitters from the axon into the synapse. The neurotransmitters cross the synapse and bind to special molecules on the other side, called receptors. Receptors are located on the dendrites. Receptors receive and process the message.

Axon terminal What is ????

Axon terminal What is ????

Axon terminal What is ????

Axon terminal What is ????

Axon terminal What is ????

Axon terminal What is ????

myelin sheath dendrites cell body synapse Review The __________________ protects the axon and helps messages travel faster. The __________________ receives messages from other neurons. The __________________ contains the nucleus and directs the activities of the cells. Messages travel through a space called the __________________ between neurons. myelin sheath dendrites cell body synapse

Make a pipe cleaner model of a neuron. Extension: Make a pipe cleaner model of a neuron.

RESOURCES http://images.google.com/imgres?imgurl=http://www.drugabuse.gov/JSP/MOD3/images/NEURON2.gif&imgrefurl=http://www.drugabuse.gov/JSP/MOD3/page3.html&usg=__rzbUKVLZ-VJ0FmcIhJ4b9t_lA4k=&h=350&w=350&sz=9&hl=en&start=16&tbnid=T-_maaMtqaqiAM:&tbnh=120&tbnw=120&prev=/images%3Fq%3Dneuron%26gbv%3D2%26hl%3Den%26sa%3DX http://www.biotechlearn.org.nz/var/biotechlearn/storage/images/focus_stories/transgenic_cows/images/a_nerve_cell/219060-1-eng-AU/a_nerve_cell_large.jpg http://upload.wikimedia.org/wikipedia/commons/thumb/b/bc/Neuron_Hand-tuned.svg/400px-Neuron_Hand-tuned.svg.png