Every person has their own part to play or if you want to get scientific then a niche. And if somebody doesn't do their job then it could slow everyone else down. Maybe I don't fully understand the question, But I hope its right.
The answer is Liver disease
Muscular tissues or cells expand and contract to move the body
The hormone ADH operates by negative feedback mechanism in that when the body's tissues lack water, it causes the nephrons to retain water to prevent the body's tissues drying out.