1 In-text citations in parenthesis, with only the author's last name and page number included (Smith, p. 4). 2  Double-spaced lines, but with no extra line breaks between each citation. 3  Footnotes (superscripted) also used to provide non-essential information.
Muscularis Extema is the layer of the digestive tract wall that is responsible for peristalsis.
The wavelike contractions of the smooth muscle in the gastrointestinal system are called peristalsis. The purpose of peristalsis is to push boluses of food along the gastrointestinal tract. This is achieved by the waves of contractions in the smooth muscle followed by relaxation of the muscles, pushing the bolus (ball of food) a bit further along the digestive tract with each contraction. These contractions move food or chyme through the esophagus, and intestines.