Question

7. Explain what happens at a microscopic level inside a muscle fiber during

beginning with the nerve impulse.

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SHEETS

Answer 1

1. contraction

2. actin

3. tendons

4. epidermis

5. dermis

6. acne

7. A nerve signal from the brain arrives at the intersection of the nerve and muscle cells and releases acetylcholine from the neuron. This triggers chemical changes in the muscle cell involving ions, including Ca2+. Calcium triggers the thick filaments, made of myosin, to attach to the thin filaments, made of actin, in the muscle cell, and the myosin pulls the actin toward the center of the muscle cell. ATP causes the release of the actin fibers, allowing the muscle to relax and the process to begin again.

Explanation: answers to all questions on this section.

Penn Foster

Answer 2

The question is not complete and is not available anywhere so it can be answered in a general way.

Answer:

At the ultrastructure level the nerve cell, has all the organelles in it. The organelles inside the cell helps in maintaining the cell alive and remains functional.

These include organelles such as nucleus, nucleolus and Golgi apparatus and mitochondria.

The microscopic level inside a muscle fiber is same like that of other cells besides the number of mitochondria is more.