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.
Pupil and iris: The pupil is the circular opening in the colored part of the eye which is the iris. The iris dilates or opens and contracts to let in more or less light. Lens: Resembles the lens of a camera and focuses the light, changing shape as it takes in light reflected from objects near and far.