Which one of the following is an Ectodermal Derivative?
(D) Muscles of the Iris [IBS7 - 346; Grays40 - 701; Grays39 - 722/EctodermMesodermEndodermNeuroectodermNeural crestEpidermis, hair, nailsMuscle (smooth, cardiac, skeletal)Epithelial lining of Gastrointestinal tractAll neurons within brain and spinal cordGanglia: dorsal root, cranial, autonomicCochlear duct, semicircular ductsExtraocular muscles (preotic somites)Muscles of the tongue (occipital somites)Trachea, bronchi, lungsRetinaSchwann cellsEnamel of teethConnective tissue, dermis of skinBiliary apparatusNeurohypophysisPia and arachnoidAdenohypophysisBone, cartilageUrinary bladder, urethraAstrocytes, oligoden- drocytesAdrenal medullaLens of the eyeBlood and lymph vesselsVagina Parafollicular cells (calcitonin)Parotid glandHeartAuditory tubeAorticopulmonary septumMammary glandsAdrenal cortexMiddle ear cavityDilator and sphincter pupillae muscle.Epithelial lining of lower anal canalSpleenParenchyma of LiverCiliary muscleKidneyPancreasDura materTestes, ovariesSubmandibular glandSublingual gland ThyroidParathyroid# Muscles of Iris arc ectodermal in origin:> All other muscular (smooth, cardiac and skeletal) muscles are mesodermal in origin.> Only the muscles of Iris are exception in origin (ectodermal), whereas all other visceral muscles are derived from mesoderm.> The musculature of the iris (Sphincter and dilator pupillae) is of ectodermal origin (optic cup) but the ciliary muscle is mesodermal.
Muscles of the Rectum
Muscles of the Blood vessels
Muscles of the Larynx
Muscles of the Iris
Misc.