![]() ![]() From the Edinger-Westphal nucleus efferent impulses travel with the oculomotor nerve and reach the sphincter pupillae muscle and ciliary muscle after relaying in the accessory and ciliary ganglion. From the parastriate cortex, the impulses are relayed to the Edinger-Westphal nucleus of both sides through the occipitomesencephalic tract and the pontine centre. This efferent fibres relay in the accessory ganglion before reaching the sphincter pupillae muscle.Īccommodation reflex pathway: Here afferent impulses are extended from the retina to the parastriate cortex through the “optic nerve, optic chiasma, optic tract, lateral geniculate body, optic radiations and striate cortex. By this the impulse is relayed to the Edinger-Westphal nucleus and the subsequent efferent pathway of near reflex is along the oculomotor nerve. There is a assumption that afferent fibers from the medial rectus travel centrally through the oculomotor nerve to the mesencephalic nucleus of the trigeminal nerve, To a presumptive centre of convergence in the tectal or pretectal region. This contains two main components (1) Convergence reflex, i.e., constriction of pupil on convergence and (2) Accommodation reflex, i.e., constriction of pupil along with accommodation.Ĭonvergence reflex pathway: Here afferent pathway is still not cleared. Near reflex: it occurs when we look at near object.Postganglionic fibers travel along the short ciliary nerves to innervate this sphincter pupillae. The pre ganglionic fibres enter the inferior division of the third nerve and via the nerve to the inferior oblique reach the ciliary ganglion to relay. Efferent pathway it consists of the parasympathetic fibres which arise from the Edinger-Westphal nucleus in the midbrain and travel along the oculomotor nerve. ![]()
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