###Rationale: Ans. d. Ciliary muscles (Ref: Parson 20/e p5; Grays Anatomy 40/ep702) Ciliary muscles develop from Neural crest, not from neural crestDerivative of neural ectoderm:Ciliary- body epitheliumQIris epitheliumQSmooth muscles of iris (constrictorQ and dilator pupillaeQ)Part of vitreousRetinal pigment epitheliumQRetinaQ (its 9 sensory- layers)Optic vesicle and cupOptic nerveQ (fibers)Primordial Tissues and Ocular DerivativesNeural-EctodermSurface-EctodermMesodermNeural crest* Ciliary body epitheliumQ* Iris epitheliumQ* Smooth muscles of iris (constrictorQ and dilator pupil laeQ)* Part of vitreous Retinal pigment epitheliumQ* Retina (its 9 sensory layers) Optic vesicle and cup * Optic nerveQ (fibers)* Conjunctival epithelium* Corneal epithelium* Lacrimal glands * Tarsal glands * Lens* Extra-ocular musclesQ* Vascular endothelium of eye and orbit * Corneal stroma* Sclera* Iris* Choroid* Part of vitreous* Orbital bones* Orbital connective tissue* Ciliary musclesQ * Ciliary ganglionQ* Schwann cells of ciliary nerves* Meningeal sheath of optic nerve* Conjunctival and uveal melanocytes* ScleraQ* Trabecular meshwork of endothelium * Corneal stroma, keratocytes and endotheliumQ* Iris stroma * Choroidal stroma Part of vitreous

###Answer: OPTION D IS CORRECT.
###Question: Which of the following is not a derivative of neural ectoderm?
###Options:
A. Sphincter pupillae
B. Retina
C. Dilator pupillae
D. Ciliary muscles
