Nerve Impulse

Nerves The Nervous System CONTROLS and COORDINATES ALL ESSENTIAL FUNCTIONS of the human body. The Nervous System RECEIVES and RELAYS information about activities within the body and monitors and responds to INTERNAL and EXTERNAL CHANGES. The functioning Nervous System is an enormous network of "one-way streets

The Nervous System has FOUR FUNCTIONS that enable the body to respond quickly 1. Gathers information both from the outside world and from inside the body. (sensory) 2. Transmits the information to the processing area of the brain and spinal cord. 3. Processes the information to determine the best response.  (integrative) 4. Sends information to muscles, glands, and organs (effectors) so they can respond correctly.  Muscular contraction or glandular secretions. (motor)

The Speed of a Nerve Impulse As an impulse moves down a myelinated (covered with myelin) axon, the impulse JUMPS from Node to Node instead of moving along the membrane. This jumping from Node to Node greatly increase the speed of the impulse. Some myelinated axons conduct impulses as rapid as 200 meters per second.

74% of Pittsford High School students have never used marijuana They get high in other ways: ski mountain bike ultimate frisbee hang out with friends exercise basejumping or wrestle tigers 2009 Youth Risk Behavior Survey

Synapse The point of contact at which impulses are passed from one cell to another are known as THE SYNAPTIC CLEFT OR SYNAPSE. Neurons that transmit impulses to other neurons DO NOT actually touch one another.  The Small Gap or Space between the axon of one neuron and the dendrites or cell body on the next neuron is called the Synapse. 

Neurotransmitters The Axon Terminals at a Synapse contain tiny vesicles, or sacs. These tiny vesicles are filled with CHEMICALS known as NEUROTRANSMITTERS. (Acetylcholine) A NEUROTRANSMITTER is a chemical substance that is used by one neuron to signal another. 

Synaptic Clef Continued When an impulse reaches the Axon Terminal, dozen of vesicles release the Neurotransmitter into the Synaptic Cleft (GAP). The molecules of the neurotransmitter diffuse across the gap and attach themselves to SPECIAL RECEPTORS on the membrane of the neuron receiving the impulse. If enough neurotransmitter becomes attached to the cell membrane of the adjacent nerve cell, it stimulates it to continue the impulse.