Mydriasis iris sphincter, composed of circularly arranged muscle fibers, and the iris dilator, composed of radially arranged muscle fibers. The sphincter is innervated by (signaled by nerves of) the parasympathetic nervous system, and the dilator by the sympathetic nervous system. Sympathetic stimulation of the adrenergic receptors causes the contraction of the radial muscle and subsequent dilation of the pupil. Conversely, parasympathetic stimulation causes contraction of the circular muscle and constriction of the pupil. The mechanism of mydriasis depends on the agent being used. It usually involves either a disruption of the parasympathetic nerve supply to the eye (which normally constricts the
The Widening Gyre (album) Donegal Jig" 11. "Lurgy Streams" (song) 12. "The Triple T" (a.k.a. "Thomas Tourish's Tune") 13. "Far beyond Carrickfinn" (song) «Áit shéimh gan smál—slán slán go fóill—macalla do ghlór ar feochan na gaoithe.» «A glentle unblemished place—goodbye for now—the echo of your voice on the breath of the breeze.» 14. "The Road Home" (slow house) Prior to the release of "The Widening Gyre", Altan had already played live in concert (at least) one track from the new album, "The Tin Key/Sam Kelly's Jig/The Gravediggers (Jigs)", during (at least) one of their 2014 shows (i.e. their last show of 2014: on 5