The Central Nervous System Is Lacking in Animals That Have

question 34

Multiple Choice

The central nervous system is lacking in animals that have

• A) a complete gut.
• B) bilateral symmetry.
• C) radial symmetry.
• D) a closed circulatory system.
• E) excitable membranes.

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Definitions:

Spontaneous Depolarization

The self-initiated transition of a cell's membrane potential to a less negative value.

Cardiac Electrical Impulse

The electrical signals that stimulate the heart to contract, crucial for maintaining a consistent heart rhythm.

SA Node

Sinoatrial node, the heart’s natural pacemaker, located in the right atrium, responsible for setting the rate of heart beats by sending out electrical impulses.

Asystole

A state of no cardiac electrical activity, leading to a lack of contraction of the heart and cessation of blood flow; essentially, cardiac arrest.