Question

Motor Nerve Function Procedure:

1. Motor nerves can be "activated' on the surface of the forearm using low level electrical stimutation.
2. Take the electronic stimulator and place the two electrodes on the ventral surface of the forearm.
3. Set the stimulator on its lowest settings and turn it on by turning the knob at the top of the device:
4. SLOWLY increase the frequency and amplitude settings until you see the muncles contract and reiax.
What process does the electrical stimulator cause in a nerve? (Remember that a nerve is made up of the axons of many neurons) it cause them to twitch and flinch (thestly on middle finger) because of action pretential

Answer 1

The electrical stimulator causes action potentials in motor nerves, leading to the release of acetylcholine at the neuromuscular junction and subsequent muscle contraction. This artificial stimulation mimics natural nerve impulses and is critical for muscle activity.

Step-by-step explanation:

When an electrical stimulator is used on motor nerves, it elicits action potentials in the axons of neurons. These action potentials subsequently cause the release of the neurotransmitter acetylcholine at the neuromuscular junctions, initiating muscle contractions. The electrical stimulator mimics the natural signals that would typically come from the central nervous system, signaling the muscles to contract.

Mechanism of Action

The process begins when the electrical stimulator induces a threshold-level electric current that depolarizes the neurons. This change in voltage opens voltage-gated sodium channels, causing an influx of sodium ions and resulting in the propagation of an action potential along the axon. The action potential travels to the neuromuscular junction, where it triggers the release of acetylcholine from the nerve terminal into the synaptic cleft.

Neuromuscular Junction and Muscle Contraction

Acetylcholine binds to receptors on the muscle fiber's membrane, causing sodium channels on the muscle cell to open and generate a muscle action potential. This leads to a cascade of events that result in muscle contraction. The process by which a motor neuron initiates a muscle contraction is essential for voluntary movements as well as reflexes and is critical for tasks ranging from simple motions to complex coordinated activities.

Understanding the Importance of Action Potentials

The generation of action potentials is a fundamental aspect of nerve function. This electrical activity is crucial for communication between the nervous system and muscle tissue. Without these signals, muscles would remain inactive and unable to respond to stimuli, which highlights the importance of properly functioning motor nerves and their associated pathways.