Learning Objectives

After completing this series of learning modules you will be able to describe the pathway of air flow to and from the alveoli, recognize clinical and physiological examples of conditions that alter alveolar ventilation and, through application of the role of blood CO₂ levels in regulating respiration, predict and explain the body's compensatory responses that will maintain homeostasis.  The detailed learning objectives are presented below.

1:    MODULE 1:  After completing this module, you will be able to summarize the role of the lungs in clearing CO₂ from the bloodstream by: 

1.1:   Tracing the pathway of airflow into and out of the lungs, identifying each component of the pathway and distinguishing between elements of the conducting and respiratory zones, respectively.

1.2:   Identifying and differentiating between the following in terms of their CO₂ partial pressures:

a)       inspired, alveolar and expired air

b)       pulmonary and systemic arterial and venous blood

1.3:   Defining tidal volume as a composite of dead space volume and alveolar ventilation

1.4:     Using definitions of inspiratory and expiratory reserve volumes and specific examples to illustrate and justify the statement: “More effective lung ventilation is achieved by decreasing the rate and increasing the depth of breathing”.

2:      MODULE 2: After completing this module, you will be able to delineate the role of blood CO₂ levels in regulating lung ventilation by:  

2.1:    Outlining the physiological process by which air is moved into and out of the lungs under resting conditions and, given a diagram of the brainstem, locating the ventral respiratory group (VRG) and justifying its designation as the pacesetting inspiratory centre of the body.

2.2:    Using the carbonic acid-bicarbonate equilibrium reaction to link CO₂ levels with pH and explain the mechanism by which CO₂ levels regulate the rate and depth of breathing  via the VRG.

3:        MODULE 3:, After working through the applied samples, you will recognize various clinical and physiological scenarios as representations of alterations in dead space volume that have associated influences on blood CO₂ clearance and the regulation of lung ventilation by the VRG.  This module will allow you to: 

3.1:     Develop and use a functional  definition of dead space volume to recognize extrinsic examples of increases in this volume and to explain the physiological basis of the body’s compensatory responses.

3.2:     Extend your comprehensive definition of dead space volume developed in 3.1 to additionally recognize clinically-relevant examples of dead space volume.