Let's Take for example the activation of renin-angiotensin system, renin is secreted by the kidney, then it will convert the angiotensinogen (previously dry by the liver) into angiotensin I, then it will be converted into angiotensin II by the enzyme conversion at the level of the lungs, and finally angiotensin II will act at the level of the vessels to exert the vasoconstriction.
This example shows the harmony between the different organs (the kidneys, the liver, the lungs and the vascular system) for the functioning of the renin-angiotensin system.