Part A (Q4): Define Alzheimer's disease.

Alzheimer's Disease is the most common cause of dementia among older adults. It is an irreversible, progressive neurodegenerative brain disorder that slowly destroys memory, thinking skills, and eventually, the ability to carry out the simplest tasks of daily living.

• Pathology: It is characterized by the abnormal build-up of proteins in the brain—amyloid plaques and tau tangles—which disrupt communication between brain cells, leading to cell death and brain shrinkage.
• Symptoms: It begins with mild memory loss (forgetting recent conversations). As it progresses, individuals experience severe confusion, disorientation regarding time and place, mood changes (aggression, paranoia), and eventually lose the ability to speak, swallow, or walk. It invariably leads to complete dependency on caregivers.