Answer
Smooth muscle has different contraction abilities from striated muscle. Unlike skeletal muscle when smooth muscle is stretched, it is still able to contract.
Visceral (single unit) smooth muscle has a stress relaxation response. When a hollow organ like the urinary bladder receives urine from the ureters, it stretches and this triggers a contraction response. But this is followed immediately by a relaxation response; so the organ resets and does not empty prematurely.
Work Step by Step
If the stress-relaxation response did not take place in the smooth muscles, urine would be expelled almost as soon as it dribbled into the bladder, and one would have to be going to the bathroom continuously all day.
