Search results
Results from the WOW.Com Content Network
Dilation and constriction of the pupil. Pupillary response is a physiological response that varies the size of the pupil, via the optic and oculomotor cranial nerve.. A constriction response (), [1] is the narrowing of the pupil, which may be caused by scleral buckles or drugs such as opiates/opioids or anti-hypertension medications.
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 pupil) or overactivity of the sympathetic nervous ...
Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurons send axons to neurons of the Edinger-Westphal nucleus whose visceromotor axons run along both the left and right oculomotor nerves .
A contracted pupil during sleep may be an indication the brain is replaying new memories while a dilated one may hint at older memories being relived, a new study suggests. The study, published in ...
The pupillary sphincter muscle and pupillary dilator muscle control the iris to adjust the size of the pupil to adjust how much light enters into the eye. The pupillary dilator muscle increases the pupillary diameter and it is arranged radially, but the pupillary sphincter muscle is responsible for the constriction of the pupil's diameter and ...
It explains the defining features of a tonic pupil: (1) The pupil does not react to light. The original light-reaction neurons have been destroyed. (2) Tonic constriction with attempted near vision. Aberrant regeneration of nerve fibers intended for the ciliary muscle causes abnormal, tonic contraction of the pupil with accommodation.
Whereas, the pupil is the passive opening formed by the active iris. Pupillary reflex is synonymous with pupillary response, which may be pupillary constriction or dilation. Pupillary reflex is conceptually linked to the side (left or right) of the reacting pupil, and not to the side from which light stimulation originates.
The paper detailed that a friendly expression is shown when the ears and whiskers move forward while the eyes close, and an aggressive cat has constricted pupils, ears flattened against the head ...