How do the circulatory, excretory and respiratory systems work together to maintain ph homeostasis?

The pH balance is regulated mostly by the kidney(excretory) and the lungs(respiratory). The kidney will excrete a number of acid/base molecule based on the blood pH. When the body excess in H+, it will excrete acid to make the blood more base.
The respiratory will control the level of carbon dioxide. Carbon dioxide will be changed into bicarbonate and H+ which makes the blood acidic. When the blood is acid, the carbon dioxide is removed more vigorously.

Predator instincts is what causes it