Autonomic nervous system sympathetic and parasympathetic

The answer is the subdivisions of the Autonomic nervous system.

Explanation:

The sympathetic and parasympathetic are the subdivisions of the Autonomic Nervous System. Their actions are usually antagonistic to each other.

the abdomen (less formally called the belly, stomach, tummy or midriff) constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. the region occupied by the abdomen is termed the abdominal cavity. the stomach secretes acid and enzymes that digest food. ridges of muscle tissue called rugae line the stomach. the stomach muscles contract periodically, churning food to enhance digestion. the pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.