Iris dilator muscle the superior orbital fissure. From there, they travel with the nasociliary nerve and then the long ciliary nerve. They then pierce the sclera, travel between sclera and choroid to reach the iris dilator muscle. They will also pass through ciliary ganglion and travel in short ciliary nerves to reach the iris dilator muscle. The pupillary dilator acts to increase the size of the pupil to allow more light to enter the eye. It works in opposition to the pupillary constrictor. Pupil dilation occurs when there is insufficient light for the normal function of the eye, and during heightened sympathetic activity,
Striated muscle tissue Striated muscle tissue Striated muscle tissue is a muscle tissue that features repeating functional units called sarcomeres, in contrast with smooth muscle tissue which does not. The presence of sarcomeres manifests as a series of bands visible along the muscle fibers, which is responsible for the striated appearance observed in microscopic images of this tissue. There are 3 types of striated muscles: Contractions in striated muscles are voluntary, except for the heart muscle, in which contractions are regulated involuntarily by the sinoatrial node. Cardiac muscle is often treated separately from the other striated muscles, as it has different characteristics. During