Gastrointestinal System Nursing Exam Questions Related

Review Gastrointestinal System Nursing Exam Questions related questions and content

The defaecation reflex:

  • A. Is initiated by stretching the anal canal
  • B. Is integrated in a control center in the lumbar spinal cord
  • C. Is integrated in a control center in the sacral spinal cord
  • D. Is controlled by the vagus nerve
Correct Answer: C

Rationale: The correct answer is C because the defecation reflex is integrated in a control center in the sacral spinal cord. This is due to the presence of the parasympathetic nerves that control the smooth muscles of the colon and rectum in the sacral region. The sacral spinal cord is responsible for coordinating the reflexive relaxation of the internal anal sphincter and contraction of the rectum during defecation. Choices A and B are incorrect because the initiation and integration of the defecation reflex do not involve the anal canal stretching or the lumbar spinal cord. Choice D is incorrect as the defecation reflex is not controlled by the vagus nerve, which is primarily responsible for the parasympathetic innervation of organs in the thorax and upper abdomen.