Final answer:
Parkinson's disease features four major motor symptoms: bradykinesia, muscle rigidity, tremors, and postural instability. Cognitive decline and mood disorders also accompany the disease in advanced stages. The loss of dopaminergic neurons and Lewy bodies are characteristic pathological markers.
Step-by-step explanation:
Parkinson's disease is a degenerative disorder of the central nervous system that primarily affects movement. There are four major motor features of Parkinson's disease:
- Bradykinesia - referring to the slowness of movement and a general reduction in spontaneous motion.
- Muscle Rigidity - which is the stiffness of the limbs and trunk.
- Tremors - characterized by shaking, commonly occurring in the limbs at rest and diminishing during voluntary movements or sleep.
- Postural Instability - leading to impaired balance and coordination, often resulting in difficulties with walking and a tendency to fall.
In addition to these motor symptoms, non-motor features such as depression, dementia, and cognitive decline, are commonly associated with advanced stages of the disease. The pathology of Parkinson's includes the loss of dopaminergic neurons in the substantia nigra and the presence of Lewy bodies within the affected neurons.