If Both the SA Node and the AV Node Fail

question 65

Multiple Choice

If both the SA node and the AV node fail, what would be the expected outcome of impulse rate within the heart?

• A) The rate would be 30 -40 beats per minute due to the concentration of pacemaker cells in the Purkinje fibers.
• B) The sympathetic nervous system takes over and maintains normal heart rate.
• C) The individual would be in heart failure or have a myocardial infarction due to the lack of a beating heart.
• D) The vagus nerve takes over and maintains a normal heart rate.
• E) The heart is autorhythmic therefore it continually beats even after death because death is defined as a lack of brain waves.

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Definitions:

Incus

A small anvil-shaped bone in the middle ear that transmits sound vibrations from the malleus to the stapes.

Cerumen

A yellowish waxy substance secreted in the ear canal, known as earwax.

Otopyorrhea

The discharge of pus from the ear, often resulting from an ear infection.

Endolymph

A fluid contained in the membranous labyrinth of the inner ear, crucial for hearing and balance.