Select the Correct Statement About the Function of Myocardial Cells

question 31

Multiple Choice

Select the correct statement about the function of myocardial cells.

• A) The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction.
• B) Cardiac muscle cells are innervated by sympathetic, parasympathetic, and somatic nerve fibers so that the nervous system can increase heart rate.
• C) The refractory period in skeletal muscle is much longer than that in cardiac muscle.
• D) The entire heart contracts as a unit or it does not contract at all.

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Definitions:

Dizygotic Twins

Also known as fraternal twins, these are siblings born from two separate eggs fertilized by two different sperm, resulting in genetically distinct individuals born at the same time.

Fraternal Twins

Twins that develop from two separate eggs fertilized by two different sperm, resulting in siblings that are genetically unique from each other.

Correlation

A statistical measure that describes the extent to which two variables change together, but not necessarily indicating that one causes the other.

Intelligence

The overall capacity of an individual to understand complex ideas, adapt effectively to the environment, learn from experience, and engage in various forms of reasoning.