Final answer:
Parkinson's disease is a neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, leading to symptoms such as tremors, rigidity, slowed movement, and postural instability. Additional symptoms may include cognitive decline and depression. Treatments aim to increase dopamine levels in the brain, with L-DOPA as a common medication.
Step-by-step explanation:
Parkinson's disease is a neurodegenerative disorder that primarily affects the motor system. The disease is characterized by the loss of dopamine-producing neurons in the substantia nigra, which is a region in the brain that plays a critical role in regulating movement. This loss leads to cardinal symptoms such as muscle tremor, muscle rigidity, bradykinesia (slowed movement), and postural instability. Additional symptoms can include cognitive decline, depression, and in the advanced stages, dementia.
Though the exact cause of neuronal degeneration in Parkinson's disease is not fully understood, both genetic mutations and environmental factors are implicated in the disease's progression. Treatments focus on increasing dopamine levels in the brain, with L-DOPA being a commonly used medication; however, its effectiveness can diminish over time, and it can have significant side effects.