41. A prime example of this is when the residential bacterium E . coli of the GI tract enters the urinary tract. 42. Exit occurs through the GI tract or the reproductive tract and expulsion involves arrest of the beetle s own reproductive capabilities. 43. Metoclopramide, a dopamine D 2 receptor antagonist, increases contractility and resting tone within the GI tract to improve gastric emptying. 44. Cancers of the GI tract that are shown to be due, to some extent, to field defects include colon cancer. 45. The GI tract fills with air while the lungs do not receive a proper air supply, preventing them from inflating fully. 46. The suspensory muscle marks the end of the duodenum and the division between the upper gastrointestinal tract and the lower GI tract . 47. The second vital secretion of the GI tract is that of digestive enzymes that are secreted in the mouth, stomach and intestines. 48. While some of these enzymes remain embedded in the wall of the GI tract , others are secreted in an inactive proenzyme form. 49. Peristalsis refers to the rhythmic contractions whereby material is propelled through a tube, commonly where food is propelled through the GI tract . 50. In coxsackie 4B virus, there is a potential for involvement of class I loci, particularly those expressed in the GI tract .
