Severe injury to skeletal muscle can be significant enough to raise CK-MB levels above normal, but such injury doesnât usually cause a high relative index. If your doctor suspects injury to both heart muscle and skeletal muscle, troponin is a more accurate test for identifying a heart attack.
The radial smooth muscle layer (dilator pupillae) is responsible for dilating the pupil. Source(s): http://en.wikipedia.org/wiki/Iris_%28ana...http://en.wikipedia.org/wiki/Dilator_pup...LaughingMan Â· 8 years ago.he iris is composed of two smooth muscle layers, arranged radially and circularly.
The pigmented area around the pupil is the iris. Along with supplying a person's eye color, the iris is responsible for acting as the pupil's stop, or sphincter. Two layers of iris muscles contract or dilate the pupil to change the amount of light that enters the eye. Behind the pupil is the lens, which is similar in shape and function to a camera lens.