- After consuming large amounts of food, digestion starts to occur. When it comes to digestion, a person does not need to think about it in order for it to occur. As to why digestion is under the autonomic nervous system, specifically the parasympathetic nervous system.
Organs:
*Esophagus - once a person swallows food, it travels into the esophagus wherein the brain signals its muscles to conduct peristalsis which is a wave-like movement that helps food move down the gastrointestinal (GI) tract.
*Lower esophageal sphincter - this ringlike muscle, that is usually closed to keep substances from the stomach to flow back into the the esophagus, is found the end of the esophagus that relaxes to lets food pass into the stomach.
*Stomach - the brain signals the creation of stomach acid and enzymes to help break down food through the glands found in the stomach lining. The muscles then start moving to help mix digestive juices and food.
*Small intestine - muscles of the small intestine also mix digestive juices from different organs in the body such as the pancreas and food, in which the small intestine absorbs water and nutrients into the bloodstream. Movement again occurs through muscle movement wherein waste travels into the large intestine.
*Large intestine - the large intestine once more absorbs water. Peristalsis then occurs to help transport waste such as undigested food, fluid to the rectum.
2. My friend driving home from work and listening to her favorite music are things she deliberately did, however, a bicycle coming out of nowhere is not something she had in mind which triggered her fight or flight response, which is under the autonomic nervous system that caused her heart to beat rapidly and increase her heart rate