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Conduction of action potentials

By: HWC, Views: 6758

• Action potentials must be rapidly conducted over long distances in order for the nervous system to communicate with other cells. • Propagation of an action potential uses processes similar to those that generate the potential at the trigger zone. • a When a graded potential reaches ...

Action potentials - electrical characteristics and generation

By: HWC, Views: 6555

• An action potential is the nervous impulse or signal for long distance communication. Each action potential is generated at the cell's trigger zone. • Action potentials are considered an all-or-nothing phenomena because they are either generated or not. • The generation of an action...

The Nerve Impulse

By: Administrator, Views: 11194

The action potential explained.

Nervous pathway to the Neuromuscular (NMJ)

By: HWC, Views: 7152

• A nervous impulse, also called an action potential, starts from the brain or spinal cord to signal skeletal muscle cell contraction. Action potentials continue along a motor neuron to the muscle cell. • The signal to contract must cross a synapse - the neuromuscular junction (NMJ) - betwe...

Summation - defined, spatial, temporal & AP generation or not

By: HWC, Views: 6529

If several presynaptic end bulbs release their neurotransmitter at about the same time, the combined effect may generate a nerve impulse due to summation Summation may be spatial or temporal • A typical neuron may have thousands of synapses. A corresponding number of postsynaptic membrane ...

Factors that affect conduction rates (myelination, axon diameter & temperature)

By: HWC, Views: 6734

• Several factors determine the rate of conduction of action potentials: • Myelination • Axon diameter • Temperature • The step-by-step depolarization of an axon is called continuous conduction and occurs along unmyelinated axons. • Neurons in the PNS have many axons that ...

Lactation and Breast Feeding

By: HWC, Views: 7460

Regulation of lactation - breast preparation • Pregnancy hormones trigger breast changes to prepare for feeding the new baby. • The amount of the hormone prolactin, essential to the initiation of lactation, increases steadily throughout pregnancy. • However, high levels of both estroge...

Phases of an Action Potential - Resting Potential, Threshold, Rising, Falling, & Recovery Phases

By: HWC, Views: 6081

In this tutorial, we will review the phases of an action potential measured from a small area of a neuron's membrane. The action potential can be divided into five phases: the resting potential, threshold, the rising phase, the falling phase, and the recovery phase. When the neuron is at rest,...

Neurotransmission at chemical synapses & Excitory and inhibitory potentials

By: HWC, Views: 6553

• A series of events occur at chemical synapses in order to communicate with the adjacent cell. • The action potential arrives at the presynaptic membrane. • The depolarization phase of the action potential opens voltage gated Ca+ channels. • increased inflow of Ca+' into the cyto...