Answer:
Negative
interacting to reduce the elevated CO2 to the a set point.
Step-by-step explanation:
As the concentration of C02 ( the stimulus) begins to rise by muscular contraction, chemo-receptors in the breathing center of the hypothalamus detected this stimuli as blood circulate through, and send sensory inputs to the brain and spinal cord.
Motor output from the brain and spinal cord through the breathing control center, stimulated the respiratory muscles to contract,.Therefore the rate of breathing increases . Thus as the concentration of CO2(stimulus)rises, rate of breathing increases, to reduce it ,therefore acidosis of the blood is prevented.
Thus a rise in the level of input stimulus(elevated blood CO2 Conc,) leads to corresponding increases in the output signals(breathing) to reduce the blood CO2 concentration back to the set point. This is negative feedback mechanism.
Thus both the respiratory and circulatory system performs homeostatic interaction to maintain stable blood pH from fluctuating CO2 concentration.