1. Which of the following mechanisms is primarily responsible for the maintenance of homeostasis in the human brain? A. Synaptic plasticity B. Blood-brain barrier C. Glial cell function D. Neuronal apoptosis Answer: B. Blood-brain barrier Rationale: The blood-brain barrier is crucial for maintaining the homeostatic balance of the brain's environment, protecting it from pathogens and regulating the transport of nutrients and waste products. 2. During a stroke, the disruption of cerebral blood flow affects homeostasis by: A. Increasing intracranial pressure B. Altering neurotransmitter release C. Impairing glucose metabolism D. All of the above Answer: D. All of the above Rationale: A stroke disrupts cerebral blood flow, leading to increased intracranial pressure, altered neurotransmitter release, and impaired glucose metabolism, all of which affect brain homeostasis. 3. In the context of neurological homeostasis, astrocytes are known to: A. Generate action potentials B. Regulate synaptic transmission C. Produce myelin sheath D. Modulate blood flow Answer: D. Modulate blood flow Rationale: Astrocytes play a role in modulating blood flow to different regions of the brain, thereby contributing to the maintenance of homeostasis by ensuring adequate nutrient and oxygen supply. 4. The role of the hypothalamus in homeostasis includes regulation of: A. Sleep-wake cycles B. Body temperature C. Appetite and satiety D. All of the above Answer: D. All of the above