Final answer:
The parasympathetic nervous system (PNS) can lower the metabolic rate, while the sympathetic nervous system (SNS) can increase it.
Step-by-step explanation:
The parasympathetic nervous system (PNS) can have an effect on metabolic rate. The PNS is responsible for the rest and digest functions of the body, which include promoting digestion, conserving energy, and reducing metabolic rate.
When the PNS is activated, it can lower the metabolic rate. This can be seen in activities such as eating a meal or relaxing after a stressful event. The body shifts its focus to digestion and relaxation, which leads to a decrease in energy expenditure and metabolic rate.
On the other hand, when the sympathetic nervous system (SNS) is activated, it can increase the metabolic rate. The SNS is responsible for the fight or flight response and increases energy expenditure to prepare the body for action. This can be seen in activities such as exercising or being in a stressful situation.