American Association of Critical-Care Nurses (AACN) Certification Practice Test

Which of the following statements regards the dopamine depletion in Parkinson's disease?

1. It results in weakness and wasting of muscles.

2. It affects the autonomic nervous system exclusively.

3. It leads to lack of voluntary movement control.

4. It does not affect muscle tone.

The correct answer is: It leads to lack of voluntary movement control.

In Parkinson's disease, dopamine depletion has a significant impact on the brain's ability to regulate movement, particularly in areas responsible for voluntary motor control. Dopamine is a crucial neurotransmitter that facilitates communication between neurons that control movement and coordination. When dopamine levels decrease, it disrupts this communication, leading to a condition known as bradykinesia, which is characterized by an overall reduction in voluntary movements. This results in a lack of ability to initiate and control movements effectively, which aligns with the explanation for why this statement is correct. The other options provided do not accurately represent the effects of dopamine depletion in Parkinson's disease. For instance, while there may be some muscle weakness in advanced stages, the primary issue is not muscle wasting but rather the impairment of the brain's signaling mechanisms for movement. Also, although the autonomic nervous system can be affected in Parkinson's, the disease is primarily characterized by motor symptoms directly linked to dopamine deficiency. Finally, muscle tone is often altered in Parkinson's disease, typically leading to rigidity rather than an absence of tone.