Iris dilator muscle "musculus dilator pupillae", The "Nomina Anatomica" as authorized in 1895 in Basle and in 1935 in Jena used the full Latin expression. Iris dilator muscle The iris dilator muscle (pupil dilator muscle, pupillary dilator, radial muscle of iris, radiating fibers), is a smooth muscle of the eye, running radially in the iris and therefore fit as a dilator. The pupillary dilator consists of a spokelike arrangement of modified contractile cells called myoepithelial cells. These cells are stimulated by the sympathetic nervous system. When stimulated, the cells contract, widening the pupil and allowing for more light to pass through the eye.
1st Arkansas Light Artillery Battery (Colored) was assigned to garrison duty at Pine Bluff, Ark. 7th Army Corps, Dept. of Arkansas, till December, 1864. The battery saw action at Prior Creek on September 18, 1864. The battery was involved in the Expedition to Mount Elba, Ark., and the skirmish at Saline River, January 22-February 4, 1865. Mustered out on August 10, 1865. 1st Arkansas Light Artillery Battery (Colored) The 1st Arkansas Light Artillery Battery (African Descent) was a artillery battery that served in the Union Army during the American Civil War. The regiment was composed of African American enlisted men commanded by white officers and was