Ciliary muscle is supplied by -

Ans. is 'a' i.e. Short ciliary nerves o The ciliary muscle receives only parasympathetic fibers from the short ciliary nerves that arise from the ciliary ganglion. These postganglionic fibers are part of cranial nerve V (Nasociliary nerve of the trigeminal)o Presynaptic parasympathetic signals that originate in the Edinger-Westphal nucleus are carried by cranial nerve III (theoculomotor nerve) and travel through the ciliary ganglion. Parasympathetic activation of the M3 muscarinic receptors causes ciliary muscle contraction, the effect of contraction is to decrease the diameter of the ring of ciliary muscle. The zonule fibers relax and the lens becomes more spherical, increasing its power to refract light for near vision.o The parasympathetic tone is dominant when a higher degree of accommodation of the lens is required, such as reading a book