Fossils of isolated land plant spores (Heckman et al, 2001) suggest land plants may have been around as long as 475 million years ago; Fossils of land plant spores within plant fragments (Wellman et al., 2003) date back to 425 million years ago ( these were found in Oman and appear to be liverwort-like, although elaters are noticeably absent!)
The noun PUPILLARY REFLEX has 1 sense: 1. reflex contraction of the sphincter muscle of the iris in response to a bright light (or certain drugs) causing the pupil to become smaller. Familiarity information: PUPILLARY REFLEX used as a noun is very rare. Dictionary entry details.
The ciliospinal reflex response is mainly mediated by second-and third-order sympathetic nerves to the dilatator muscle of the iris.As the pupillary response to various pharmacological agents indicates a sympathetic dysfunction in patients with cluster headache, the ciliospinal reflex was studied in 25 patients.n 18 (72%) of our 25 patients, an asymmetric and lower ciliospinal reflex response on the symptomatic side was seen. In 3 (12%) patients, there was no difference in the response. In 4 patients (16%), the incorrect side was indicated by an asymmetric reflex response.