In a reflex, the information is first detected in the sensor and travels along sensory neurons to the spinal cord. Once the action potential reaches the spinal cord, the information is transmitted across the synapse to the motor neuron.

A reflex does not require any thought input. The path taken by the nerve impulses in a reflex is called a reflex arc. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. Reflex arc: The path taken by the nerve impulses in a reflex is called a reflex arc.

Sensory neurons receive impulses and carry them from the sense organs to the spinal cord or brain. Motor neurons carry impulses from the brain and spinal cord to muscles or glands.

What is the difference between a two-neuron and a three-neuron reflex arc? A two-neuron reflex arc consists of only two types of neurons and a three-neuron reflex arc consists of all three. Why are reflexes important? Reflexes are important because they help you have a quick response to danger.

In our discussion we will examine four major reflexes that are integrated within the spinal cord: the stretch reflex, the Golgi tendon reflex, the withdrawal reflex and the crossed extensor reflex.

A nerve impulse begins when a neuron receives a chemical stimulus. The nerve impulse travels down the axon membrane as an electrical action potential to the axon terminal. The axon terminal releases neurotransmitters that carry the nerve impulse to the next cell.

The fastest nerve impulses travel at 288 km/h (180 mph) and are achieved by various nerves in the body. This was published by C.F. Stevens, in New York, in 1966, in Neurophysiology: A Primer.

The following four steps describe the initiation of an impulse to the “resetting” of a neuron to prepare for a second stimulation:

• Action potential. Unlike a graded potential, an action potential is capable of traveling long distances.
• Repolarization.
• Hyperpolarization.
• Refractory period.

Nerve impulses begin in a dendrite, move toward the cell body, and then move down the axon. A nerve impulse travels along the neuron in the form of electrical and chemical signals. The axon tip ends at a synapse. A synapse is the junction between each axon tip and the next structure.

When neurons communicate, the neurotransmitters from one neuron are released, cross the synapse, and attach themselves to special molecules in the next neuron called receptors. Receptors receive and process the message, then send it on to the next neuron. Eventually, the message reaches the brain.

The nerve impulse is a wave of depolarization traveling along the axon of the motor nerve such that the resting membrane potential of about −70 millivolt is reversed, becoming briefly positive. At the nerve terminal, the nerve impulse causes voltage-gated calcium channels at the active zones…

For example, if your finger touches a hot stove, nerve impulses support quick communication between nerve cells in the hand and the brain so you avoid a serious burn.

Neurons

The nerve cell(neuron) receives and transfers messages, thereby helping to control and coordinate the working of different parts of the body.