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An Acrid Situation

Hypercapnia’s Effects on Blood pH


Hollie L. Leavitt
Department of Biology
College of Western Idaho


This directed case study tells the story of a geriatric patient who has recently been diagnosed with idiopathic pulmonary fibrosis. It begins with him informing his granddaughter, “Jillian,” of the diagnosis. Jillian is a nursing student who is able to answer many questions for her grandfather about what is happening in his body. Acting as Jillian, students will walk the grandfather through an explanation of his disease including changes in lung structure and how these changes will affect gas exchange at the respiratory membrane (and therefore pO2 and pCO2 levels in the blood), leading to eventual acidosis. The case study allows students to synthesize many of the respiratory system learning objectives taught in a college-level introductory level anatomy and physiology class, with a focus on the bicarbonate buffer system and its role in maintaining acid-base balance in the blood. The case could also be used in nursing or other professional programs, or in high school honors or AP anatomy and physiology courses.

  • Describe the structure of the respiratory membrane and how its structure allows for gas exchange between the lungs and the blood.
  • Understand how changes to the respiratory membrane can affect gas exchange.
  • Determine how blood pO2 and pCO2 are affected by a restrictive lung disorder.
  • Describe the bicarbonate buffer system in the blood that maintains blood pH within the range of 7.35–7.45.
  • Explain how the bicarbonate buffer system responds to changes in CO2.
  • Determine the relationship between blood pCO2 and blood pH.
  • Predict how a restrictive lung disorder will change blood pH.
Keywords: Idiopathic pulmonary fibrosis; interstitial lung disease; acid base balance; bicarbonate buffer system; equilibrium reactions; respiratory system; restrictive lung disease; pulmonology; acidosis; respiratory membrane; respiratory physiology
Topical Area: N/A
Educational Level: High school, Undergraduate lower division, Clinical education
Formats: PDF
Type/Method: Directed
Language: English
Subject Headings: Anatomy   Physiology   Medicine (General)   Nursing  
Date Posted: 8/5/2019
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.

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