Explore BrainMass

Membrane Potentials, Calcium and Muscle Contraction

This content was STOLEN from BrainMass.com - View the original, and get the already-completed solution here!

1. Explain, briefly, why the 10-fold difference in concentration of Na+ across the membrane is important to excitable membranes.
2. How do voltage-gated calcium channels relate to electrical activity of the neuronal vs. sarcolemmal membrane? Concentrate on the differences. Keep your answer brief (3-4 sentences).
3. Why are muscle action potentials only the result of excitation? Think about what hyperpolarization would do for contraction.

Thank you

© BrainMass Inc. brainmass.com October 25, 2018, 10:04 am ad1c9bdddf

Solution Preview

Cells often actively pump out certain ions to polarize themselves - that is, to separate ions of different charges on opposite sides of a membrane - in order to use this gradient as a means to regulate their function. For example, neurons will do this and make use of the electrochemical gradient that builds up as a means of sending signals from one end of the neuron to the other, where more chemical signals are then stimulated by movements of this gradient to send a signal to another cell.

Excitable membranes are membranes which can depolarize, or alleviate the polarized build-up of ions on different sides of the ...

Solution Summary

380+ words explains the concentration differences in Na across excitable membranes and other related questions.

See Also This Related BrainMass Solution

Muscle contraction

Review the videos below on the steps of muscle contraction:

1) Events at the neuromuscular junction

2) Excitation-contraction coupling

3) Crossbridge cycle

These videos illustrate the steps that occur for skeletal muscle cells, which are very similar to cardiac, heart, muscle cells which contract in a very similar way.
1 Now outline how alterations at the chemical level cause complications at the organismal level: How does crude oil interrupt heart cell signaling and overall heart cell function? What does this do to the fish?
2 An outline of the research techniques used in this study, including brief description of each technique.

View Full Posting Details