Answer:
The changes described in the scenario are associated with the function of the sympathetic nervous system. When faced with a perceived threat, such as a bear walking towards him, the body's sympathetic nervous system is activated, triggering the "fight or flight" response. This response includes dilation of the pupils, sweating, and increased heart rate and blood pressure, among other physiological changes. These changes help to prepare the body to either fight the threat or run away from it.
Step-by-step explanation: