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Why does myelin on the surface of an axon causes a speedier transmission of a nerve impulse down the axon?
Because the cytoplasm of the axon is electrically conductive, and because the myelin inhibits charge leakage through the membrane, depolarization at one node of Ranvier is sufficient to elevate the voltage at a neighboring node to the threshold for action potential initiation. Thus in myelinated axons, action potentials do not propagate as waves, but recur at successive nodes and in effect "hop" along the axon, by which process they travel faster than they would otherwise.
What else can I help you with?
What causes Mercury's surface to look as it does?
the extreme heat of the planet causes it to have a high rock content and so the surface looks rocky
What causes a vechile to move forward while in drive and possible causes?
A vehicle moves forward when in drive due to the transmission transferring power from the engine to the wheels. Possible causes for a vehicle not moving forward in drive could include low transmission fluid, a faulty transmission solenoid, a defective torque converter, or a worn-out clutch (for manual transmissions).
What is the function of the acetylcholine sacs?
a small organic molecule liberated at nerve endings as a neurotransmitter. It is particularly important in the stimulation of muscle tissue. The transmission of an impulse to the end of the nerve causes it to release neurotransmitter molecules onto the surface of the next cell, stimulating it. After such release, the acetylcholine is quickly broken into acetate and choline, which pass back to the first cell to be recycled into acetylcholine again. The poison curareacts by blocking the transmission of acetylcholine. Some nerve gases operate by preventing the breakdown of acetylcholine causing continual stimulation of the receptor cells, which leads to intense spasms of the muscles, including the heart. Acetylcholine is often abbreviated as Ach.
What is the first step for nerve impulse generation?
The first step for nerve impulse generation is the depolarization of the cell membrane, which is triggered by a stimulus. This depolarization causes a change in the electrical charge of the cell membrane, leading to the opening of ion channels and the initiation of an action potential.
What factor causes atmosphere pressure?
Weight of the atmosphere above a surface.
What causes changes in momentum?
impulse
What are the causes of impulse control disorders?
The exact causes of impulse control disorders are not fully understood as of 2004. Individuals who have had serious head injuries, however, can be at a higher risk for developing impulse control disorders, as are those with epilepsy.
What causes a nerve impulse move along the nerve fiber?
Electrical diferences.
What decreases on a constant impulse?
Velocity decreases on a constant impulse, as impulse is equal to the change in momentum. When a force is applied for a certain amount of time, it results in a change in momentum which causes the velocity to decrease at a constant rate.
The SA node triggers an impulse that causes both atria to do what?
SA node sends an impulse for the atria to contract. AV node is then activated which contracts the ventricles.
How does your heart pump?
The AV node sends out an electrical impulse that causes the heart to contract.
If one incoming impulse causes several outgoing nerve impulses you know that there is a?
diverging
When is an impulse an electrical signal?
When a stimulus causes positively charged ions to diffuse into the neuron.
What causes the normal delay in transmission at the AV node What is the importance of this delay for cardiac function?
The delay occurs within the fibres of the AV node. It is important because it allows the atria to complete their contraction and empty their blood into the ventricles before the ventricles contract. There is a short delay (1 m/second) in transmission of the impulse to the ventricles.
What is demyelinating processes?
Demyelination is the process that erodes the sheath that normally protects nerve cells. This causes a reduction in the nerve impulse conduction. One of the diseases that causes this is multiple sclerosis.
How do we determine the direction of the impulse vector?
The direction of the impulse vector is determined by the direction in which the force is applied to an object. It is always along the line of action of the force. The impulse vector points in the same direction as the force on the object and causes a change in the object's momentum in that direction.
The electrical impulse that causes the heart to contract is generated in the right atrium at the?
Sinoatrial, or SA node.
