AEMCA Practice Exam

What anatomical area is primarily affected in Parkinson's disease?

1. The cerebral cortex

2. The hippocampus

3. The substantia nigra

4. The temporal lobe

The correct answer is: The substantia nigra

Parkinson's disease primarily affects the substantia nigra, which is a crucial region in the midbrain that plays an essential role in movement control. This area is responsible for the production of dopamine, a neurotransmitter that helps regulate coordination and balance. In Parkinson's disease, the neurons in the substantia nigra degenerate and die, leading to a significant reduction in dopamine levels. This deficiency results in the hallmark symptoms of Parkinson’s, such as tremors, rigidity, bradykinesia (slow movement), and postural instability. The other anatomical areas mentioned, such as the cerebral cortex, hippocampus, and temporal lobe, are involved in various cognitive functions, memory, and sensory processing but do not play as direct a role in the motor control issues characteristic of Parkinson's disease. Thus, the focus on the substantia nigra is essential for understanding the disease's pathophysiology as it pertains to movement disorders.