The authors study the classical Grodins model of respiration and the associated control problem. The Grodins system is obtained by writing down the conservation laws for \(\text{CO}_ 2\) and \(\text{O}_ 2\). Differential equations are obtained for lung, brain and tissues. Scaling and asymptotic analysis are used to reduce the model drastically to a much simplified form. The model consists of two separate controllers due to oxygen and carbon dioxide. The authors focus on the carbon dioxide controller and show that it can be considered as two coupled delay recruitment equations. It is shown that periodic and chaotic solutions may be obtained by varying controlling parameters.