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

Lacy’s Dry Run

How the Body Maintains Water Balance



Co Authors:

Ann L. Parkinson
School of Health and Sport Sciences
University of the Sunshine Coast
aparkins@usc.edu.au

Nicole B. Reinke
School of Health and Sport Sciences
University of the Sunshine Coast
nreinke@usc.edu.au

Abstract:

This interrupted case study in renal physiology and water balance follows the story of "Lacy," a star athlete, who makes poor fluid intake choices for the duration of a track and field day. Lacy notices changes in the volume and appearance of her urine as the day progresses, and eventually succumbs to suspected dehydration. Students work through questions about general body water inputs and outputs, the structure of the nephron and the locations within the nephron where water and sodium ion reabsorption take place. The hormonal control of water and sodium ion reabsorption by vasopressin (antidiuretic hormone) and aldosterone are also deliberated. Students then consider how nephron function is affected by the consumption of caffeine and the implications of body water imbalances on the functioning of the cardiovascular system. This case was developed for use in an upper-level human physiology course taken over two semesters and could be adapted for a lower-level physiology problem-based learning tutorial or extended for a pathophysiology course.

Objectives:
  • Describe the major sources of water input and output in the human body.
  • Describe the mechanisms of water loss from the human body.
  • Describe the reabsorption of water and sodium ions in the nephron.
  • Describe the effects of caffeine on nephron function.
  • Explain some of the consequences of an imbalance of body water.
  • Describe the relationship between body fluid and blood pressure.
  • Outline the mechanisms by which water is absorbed in the small intestine.
Keywords: Renal; nephron; water balance; vasopressin; aldosterone; blood pressure; water loss; dehydration; rehydration; caffeine; sports drink
Topical Area: N/A
Educational Level: Undergraduate lower division, Undergraduate upper division
Formats: PDF
Type/Method: Discussion, Interrupted
Language: English
Subject Headings: Physiology   Medicine (General)   Sports Science  
Date Posted: 11/1/2019
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



Name:
Email:
Department:
Institution:
City State:
Comments:
security code
Enter Security Code: