It is the firing of a nerve which sends an electrical signal down the axons of that nerve. The message propagates by the movement of Sodium (Na) and Potassium (K) ions in and out of the axon wall/sheath.
The electrical messages, called nerve impulses, may travel as fast as 150m per sec or as slow as 0.2m/s
a nerve impulse is an electrical signal that travels along the axon of a neurone to and from receptor.
Across a SYNAPSE, along a DENDRITE and the SOMA, and finally along the AXON.
The Synapse:
At a SYNAPSE, an impulse from the first (initiating) neuron which has reached that presynaptic neurons axon terminal causes voltage-gated Calcium ion pores to open in that axon terminal, allowing Calcium ions into that axon terminal, which causes small bags (vesicles) of chemicals (neurotransmitters) to merge with the cell membrane at the end of that axon terminal (the beginning of the synapse), releasing the neurotransmitters into the space between two neurons (the synaptic cleft), where they DIFFUSE quickly over to the SECOND neuron, usually at dendrite or dendritic spine, where the neurotransmitters bounce or slide or otherwise fit into the RECEPTOR sites of ligand-gated Sodium PORES on the SECOND or receiving neuron, causing those pores to open, allowing Sodium ions to enter the dendrites of the receiving neuron.
Dendrite, and Soma (the body of the Neuron):In and along a DENDRITE & then across the SOMA, the Sodium ions electrostatically "bump" one another, resulting quickly and finally (but with decreasing force) in somewhat of a "pileup" of Sodium ions at the AXON HILLOCK (the place on the neuron where the AXON begins). This is called ELECTROTONIC impulse conduction or transmission. The Axon: If enough dendrites have been stimulated, or one or more have been repeatedly stimulated sufficiently, to cause a big enough pile up of Sodium ions at the axon hillock (ie, resulting in a big enough voltage), then that TRIGGER will open voltage-gated ion pores, allowing more sodium ions in, which opens more voltage-gated ion pores further along the axon, which brings in more sodium ions, which open more voltage-gated pores, etc. This process continues along the axon until it reaches the end of the axon terminals. This mode of impulse conduction is called the ACTION POTENTIAL.electrical messages, called nerve impulses, may travel as fast as 150m per sec or as slow as 0.2m/s
Nerve impulses: an electrical impulse that passes from the sensory receptor (e.g. Nerve ending) along the sensory neuron to the spinal cord. The impulse then passes to a relay neurone and straight back along a motor neurone to the effector organ (e.g. muscle). The time between the stimulus and the reflex action is as short as possible. It allows you to react to danger without thinking about it.
Nerves a made up of cells called neurons. Neurons have special proteins embedded in their membranes. These special proteins allow charged particles called ions to pass through the membrane. For understanding nerve impulses, consider the movement of Sodium (Na+), Potassium (K+) and Chloride (Cl-) ions.
If you are eating a healthy diet, your body should have a full supply of these ions. They are found both inside and outside the neural cell. When at rest, the proteins in the neuron's membrane are allowing Na+ and K+ ions to exit, but they are preventing Na+ ions from entering. As a result, the neuron ends up with slightly less positive ions inside compared to outside. This difference in charge is roughly -70mv and its given the name resting potential.
A nerve impulse begins when an individual neuron receives a stimulus that enables the action potential threshold to be reached (around -50mv). The stimulus is specific for the neural receptor. In other words, a light receptor is stimulated by a particular quantity of light energy. A sound receptor is stimulated by a particular quantity of sound energy...so on. If the charge difference reaches -50mv, Na+ gates open allowing Na+ ion to rush into the cell. The charge inside the neuron climbs to roughly +30mv. This is the impulse.
One section of the neuron affects the neighboring section, and so on, the impulse is carried to its destination.
A nerve impulse is a depolarization of the neurolemma followed by a repolarization that moves progressively down the length of the axon.
The fuction of nerve impluses is for the body to communicate with other body parts and make the body work as a whole.
Nerve impulses are electrical signals.
the spinal nerve sends nerve impulses away from the CNS
Carry nerve impulses from receptors toward the central nervous system.
It's main purpose is to transport messages from one part of the body to another in the form of nerve impulses.
The characteristic of a nerve cell that relates directly to its function in receiving and transmitting nerve impulses is its king extensions. Cells are limited in size by the rate at which substances needed by the cell can enter the cell through the surface.
Nerve cells have many adaptions that make them functional. Some of these adaptions include longer axons in order to deliver action potentials a long distance. The dendrites carry the nerve impulses to the cell body. The myelin sheath increases the rate of transmission of nerve impulses.
to receive and conduct electrochemical impulses
long extensions
its long extensions
to transfer nerve impulses to the brain
the spinal nerve sends nerve impulses away from the CNS
The primary function of the peduncle is to control body movements. It sends nerve impulses from our brain to control our body.
Nerve impulses are electrical signals.
nerve impulses
Cholesterol provides insulation in neurons to improve the conduction of nerve impulses.
Carry nerve impulses from receptors toward the central nervous system.
vagus nerve
Accumulation of chemical neurotransmitters and specific protein molecules