New search
download case
  • Overview
  • Teaching Notes
  • Answer Key
  • Comments/Replies

Thyroid Troubles

A Case Study in Negative Feedback Regulation


Breanna N. Harris
Biological Sciences
Texas Tech University


In this interrupted case study, students shadow an endocrinologist as she tries to determine what is wrong with Angela Barber. Angela is a middle-aged woman presenting with symptoms suggestive of a thyroid issue. Students are given background information, patient history, and results from thyroid-specific blood tests. The exercise emphasizes the hypothalamic-pituitary-thyroid axis and particularly highlights the role of negative feedback. Students will use results from serum thyrotropin and thyroid hormone level tests, as well as patient symptoms, to come up with a diagnosis. In preparation for the diagnosis, students are asked to compare the endocrine profiles of patients with Graves' disease, Hashimoto's disease, iodine deficiency (primary hypothyroidism), and various tumors. The case was developed for college-level biology majors in a physiology course, but also has been used successfully for pre-nursing students in a non-majors anatomy and physiology course. Thus, this activity would be suitable for majors in physiology or pre-medical students, as well as allied health majors.

  • Diagram the negative feedback system of the hypothalamic-pituitary-thyroid axis.
  • Compare and contrast hyperthyroidism and hypothyroidism.
  • Explain potential causes of a goiter.
  • Compare different thyroid disorders and explain how dysregulation at various levels of the HPT axis correspond to each disorder.
Keywords: thyroid, thytopin, iodine, hyperthyroidism, feedback, Graves’ disease, iodine deficiency, hypothyroidism, HPT, Hashimoto’s disease, endocrinology
Topical Area: N/A
Educational Level: Undergraduate lower division, Undergraduate upper division
Formats: PDF
Type/Method: Directed, Interrupted
Language: English
Subject Headings: Biology (General)   Medicine (General)   Nursing   Physiology   Science (General)  
Date Posted: 9/19/2016
Date Modified: N/A
Copyright: Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

Teaching Notes

Case teaching notes are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering here.

Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

  Download Teaching Notes

Answer Key

Answer keys for the cases in our collection are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering here.

  Get Answer Key

City State:
security code
Enter Security Code: