Question

Neuron Signaling and Muscle Contraction

1) “Dissect” the various parts of an action potential by describing the status (active or nonactive) of the voltage-gated sodium channel, voltage-gated potassium channel, sodium/potassium pump, and overall voltage and/ or voltage range (in millivolts, or mV) for each of the following.

A) Resting membrane (prior to the initiation of an action potential)

B) just before threshold to just after threshold (Depolarization)

C) Rising phase of the action potential

D) Falling phase of the action potential to hyperpolarization

E) Repolarization to resting membrane potential.

2) Explain how a signal gets propogated in a neuron starting at the place a signal is received to the place a signal is transmitted.

B) Where in the neuron is the decision to generate an action potential located and what is that location called?

3) What is the name of the site where an action potential is actually generated in a neuron that is using Saltatory Conduction?

B) What is the name of the cells that generate the myelin sheath?

C) How does a myelin sheath help promote Saltatory Conduction?

4) How does an electrical signal from the axon of one neuron get transmitted to the start of an electrical signal in the next neuron?

B) What determines how much (and what type) of neurotransmitter is released into the neuronal synapse?

5) Describe the relationship between the following terms, muscle fiber, myofibril, sarcomere, sarcolemma, sarcoplasmic reticulum, and sarcoplasm.

6) Provide the steps that help bring two Z disks in a sarcomere closer to each other. Include the terms, myosin, tropomyosin, troponin, ATP, thick filament and thin filament in your answer.

7) Provide the pathway for how an action potential in a neuron leads to contraction of a sarcomere in muscle. Include acetylcholine, neurotransmitter, calcium, troponin, sarcoplasmic reticulum and tubules in your answer.

8) What key characteristics distinguish skeletal muscle from smooth muscle and smooth muscle from cardiac muscle?

B) What is the difference between a fast fiber and a slow fiber in skeletal muscle?

C) Provide a way that the composition of these fibers in a muscle cell contribute to that muscle’s function.

Answer 1

when cell depolarization occur then sodium ions enter the cells and make its positive whereas when potassium channels becomes opened then it's get outside and makes cell more negative.

+351 Depolarization Colar posto KT charmes opened Nart channel Milivolts Гtate ATPepe m Sureshold u hyperpolarization t orekt 0.3 0.4 0.1 1.2 millisecond

Whereas sodium potassium ATPase maintain the concentration gradients of sodium and potassium by emitting 3Na and 2 k + outside and inside against their concentration by using ATP hydrolysis.