Gastrointestinal Digestive System Essay

When rationally thinking about the gastrointestinal tract or digestion, nearly all of its functions are regulated by the autonomic nervous system, or involuntary, meaning that we do not consciously have to contemplate digestion for digestion to occur. With this being stated, it would make sense that almost the entire gastrointestinal tract is made up of smooth muscle. Smooth muscle is very distinctive from the other types of muscle in the body due to the fact that it is not controlled consciously, but unconsciously regulated by the autonomic nervous system through the release of neurotransmitters or hormones (McCance, 2014).

They only parts of digestion that are voluntary are the choice to digest food when we are hungry which requires ingestion and mastication of food, the first phase of the swallowing process, and excretion of waste or defecation. All other parts of digestion happen involuntarily with the assistance of the autonomic nervous system. With this being the case, only the pharynx, the upper third of the esophagus, and the external anal sphincter are composed of striated muscle. The middle third of the esophagus is the only part of the gastrointestinal tract that is composed of striated and smooth muscle. The rest of the gastrointestinal tract is composed of smooth muscle; including the lower
Another mechanism of tonic contraction of the lower esophageal sphincter includes the parasympathetic (vagus) nerve, or cholinergic vagal stimulation, which applies an inhibitory effect on the amount of sphincter pressure making it easier for the lower esophageal sphincter to contract (Goyal & Chaudhury,