APPLIED RADIOLOGICAL ANATOMY

Detailed explanation-1: -Smooth muscles-sometimes also called involuntary muscles-are usually in sheets, or layers, with one layer of muscle behind the other. You can’t control this type of muscle. Your brain and body tell these muscles what to do without you even thinking about it.

Detailed explanation-2: -Smooth muscle differs from skeletal muscle in a variety of ways, perhaps the most important being its ability to be contracted and controlled involuntarily. The nervous system can use smooth muscle to tightly regulate many of the body’s subsystems for life with no thought from the user.

Detailed explanation-3: -Smooth muscle fibers are located in walls of hollow visceral organs (such as the liver, pancreas, and intestines), except the heart, appear spindle-shaped, and are also under involuntary control.

Detailed explanation-4: -Smooth muscle, found in the walls of the hollow internal organs such as blood vessels, the gastrointestinal tract, bladder, and uterus, is under control of the autonomic nervous system. Smooth muscle cannot be controlled consciously and thus acts involuntarily.

Detailed explanation-5: -Smooth muscle cells distributed in the visceral organs are under the control of the autonomic nervous system, and contraction or relaxation of the muscle cells plays an important physiological role in the control of blood pressure, motility of the digestive, respiratory and urinary tracts and secretion.