Final answer:
The subject of this question is Biology. The Sympathetic Nervous System regulates vasoconstriction, increases peripheral resistance, increases blood pressure, causes mydriasis (pupil dilation), and closes the internal sphincter of the bladder.
Step-by-step explanation:
The subject of this question is Biology. The question is asking about a system that regulates vasoconstriction, increases peripheral resistance, increases blood pressure, causes mydriasis (pupil dilation), and closes the internal sphincter of the bladder.
This description matches the actions of the Sympathetic Nervous System. The sympathetic nervous system is responsible for the fight-or-flight response in the body and activates these responses to prepare the body for action in stressful situations.
For example, vasoconstriction helps redirect blood flow to vital organs during times of stress, such as during physical activity or when feeling threatened. Increased blood pressure helps ensure an adequate blood supply to the body's organs and tissues. Mydriasis allows the eyes to let in more light, enhancing visual sensitivity. And the closure of the internal sphincter of the bladder helps prevent urination during the fight-or-flight response.