PADI Divemaster Certification Practice Exam

The Haldanean model describes how the body absorbs and releases inert gas through what theoretical construct?

1. Systems

2. Compartments

3. Phases

4. Layers

The correct answer is: Compartments

The Haldanean model is based on the concept of compartments, which represent different body tissues or fluids that absorb and release inert gases at varying rates. In this model, the body is divided into multiple compartments, each with its own specific characteristics regarding how it interacts with inert gases such as nitrogen during diving. This approach allows for a more accurate prediction of the risk of decompression sickness, as each compartment can have a different rate of inert gas uptake and release based on factors like blood flow, tissue type, and the partial pressure of gas in the surrounding environment. For example, more vascular tissues such as muscles and fat absorb gas more quickly than less vascular tissues, contributing to the overall dynamics of how inert gas is handled during and after a dive. The use of compartments in the Haldanean model is foundational for understanding dive planning and the physiological effects of diving on the body.