If We Were Able to Artificially Alter the Membrane Permeability

question 54

Multiple Choice

If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________.

• A) threshold is reached more quickly and heart rate would increase
• B) potassium channels compensate and no change in heart rate would occur
• C) heart rate would decrease, but blood pressure would rise due to the excess sodium present
• D) tetanic contraction would occur due to the short absolute refractory period of cardiac muscle

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Definitions:

Direction

In electrical and electronic contexts, direction can refer to the path in which current flows or the orientation of a magnetic or electric field.

Valence Electrons

Electrons located in the outer orbit of an atom.

Maximum Number

The highest value in a given set or range.

Matter

Anything that occupies space.