The sympathetic and parasympathetic nervous systems are subdivisions of the

autonomic nervous system (ANS)

Explanation:

The Autonomic Nervous System (SNA) is the part of the nervous system that controls and regulates internal organs such as the heart, stomach and intestines, without the need for conscious effort by the body. It is part of the peripheral nervous system (which includes the Somatic Nervous System or SNS and SNA) and for this reason it also controls some of the body's muscles.

Thus, most organs are controlled by the sympathetic and parasympathetic nervous system. Sometimes both have opposite effects on the same organ. For example, the sympathetic system increases blood pressure while the parasympathetic system decreases it. In general, both systems work together to ensure that the body responds adequately to different situations.