Using Pulse Oximetry to Illustrate Homeostasis in the Secondary Biology Laboratory

Abstract

To survive, complex organisms must maintain homeostasis by coordinating the activity of interacting, hierarchical systems. This is a core biological idea in the Next Generation Science Standards and one that many students find challenging. The most common lab exercise used to introduce homeostasis – a mini-experiment in which students measure how physical activity affects their pulse and respiratory rate – fails to show any direct evidence of internal stability. In this article, we describe how modifying this lab using an inexpensive pulse oximeter rectifies this shortcoming, giving students the ability to collect laboratory data that show both change and dynamic stability.