Does the muscular system effect the body systems?

Answer:
it does... in the lower legs, the muscle contractions help the venous valves to keep venous flow moving upwards, helping the blood move from the feet to the heart, preventing pooling of venous bloods and conditions like varicose veins.
intercostal muscles help in breathing especially at times of high exertion like sprinting.

the heart is a muscle itself: made of cardiac muscle.

these are only some examples.
First answer by Medstud1. Last edit by Medstud1. Contributor trust: 1 [recommend contributor recommended]. Question popularity: 1 [recommend question].