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What Happened to 28 Days?

A Clicker Case About the Human Menstrual Cycle


Tamar L. Goulet
Department of Biology
University of Mississippi


This clicker case introduces the human menstrual cycle and its associated misconceptions by following the story of Ann, a newlywed college student. Ann worries that she is pregnant and confides in her friend, Karen, a biology major. By following their discussion, students learn about the follicular and luteal phases of the menstrual cycle, the hormones involved, and the negative feedback that occurs. By the end of the case, students will understand the human female menstrual cycle and be able to predict when ovulation occurs during any given cycle. The case is geared for an introductory biology class for both non-majors and majors. It could also be used in a human reproduction class.

  • Understand the human female menstrual cycle:
  • Understand when ovulation occurs during the human female menstrual cycle:
  • Counter some of the pervasive misconceptions about the human female menstrual cycle.
Keywords: Human reproduction; menstrual cycle; menstruation; menses; estrogen; progesterone; corpus luteum; luteal phase; ovary; uterus; ovulation
Topical Area: N/A
Educational Level: Undergraduate lower division
Formats: PDF, PowerPoint
Type/Method: Clicker, Interrupted
Language: English
Subject Headings: Biology (General)   Physiology   Anatomy  
Date Posted: 8/29/2011
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.

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Thanks, I've just been teaching the menstrual cycle to my International Baccalaureate Biology students, this matches perfectly.

Global Jaya International School
Tangerang 15224 Indonesia
I have adapted the PowerPoint to follow each step of Slide 18 so that it is a little clearer. If you'd like to see it, please contact me. Thank you and thanks for your great work.

Elisa Whitman
AP Biology
Stonington High School
Pawcatuck, CT

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