The two systems are not directly connected, however, without muscles you would not have blood circulation, and the immune system requires blood circulation to do its work.
the respiratory system gives us oxygen and also helps in combustion of food. So after it combusts this food, the food goes to the muscles in the form of energy.
Although the heart pumps blood with the ions of calcium necessary for the contraction and the brain sends the electrical signals for contraction the muscular systems mainly needs calcium ions for...