The smooth muscle is used in all hollow organs.
single-unit smooth muscle
Cows stomach is a smooth muscle since smooth muscle is found mostly in the walls of hollow organs.
Smooth muscle is the muscle that lines hollow organs. A classic "smooth muscle" is the arteries and veins. They have the ability to contract and relax, but are not under conscious control.
Smooth muscle activity is responsible for involuntary body activities and the contractility of hollow organs. Hollow organs include the bladder gastrointestinal tract blood vessels, and the uterus.
Cardiac muscle also may appear striated, but with only a single band crossing each bundle, the intercalated disc. Each cell possesses only one or two, large, round nuclei, which typically stain fairly dark.
Smooth muscle (involuntary)lines ducts and vessels.