<prompt> Parathyroid gland develops from?Brachial cystBrachial cleftBrachial pouchBrachial arch  <response>: ANSWER: C Brachial pouchREF: Langmans medical embryology 9th edition page 384-385See APPENDIX-6 below for BRACHIAL ARCHESInferior parathyroid develops from 3rd brachial pouch while superior parathyroid develops from 4th brachial pouch APPENDIX - 6Brachial ArchesThere are six pharyngeal arches, but in humans the fifth arch only exists transiently during embryologic growth and development. Since no human structures result from the fifth arch, the arches in humans are I, II, III, IV, and VI. The first three contribute to structures above the larynx, while the last two contribute to the larynx and tracheaPharyngealArchMuscularContributionsSkeletal ContributionsNerveArteryCorresponding Pouch Structures1stmandibulararchMuscles of mastication, Anterior belly of the digastric, Mylohyoid, Tensor tympani, Tensor veli palatiniMaxilla, mandible only as a model for mandible not actual formation of mandible, Incus and Malleus, Meckels cartilage, Ant. ligament of malleus, Sphenomandibular ligamentTrigeminal nerve V2 and V3Maxillary artery, external carotid arteryEustachian tube, middle ear, mastoid antrum, and inner layer of the tympanic membrane.2nd hyoid archMuscles of facial expression. Buccinator, Platysma, Stapedius, Stylohyoid, Posterior belly of the digastricStapes, Styloid process, hyoid lesser horn and upper part of body, Reicherts cartilage, Stylohyoid ligamentFacial nerve VIIStapedialArterymiddle ear, palatine tonsils3rdStylopharyngeusHyoid greater horn and lower part of body, thymusGlossopharyngeal nerve IXCommoncarotidInternalcarotidInferiorparathyroid,Thymus4thCricothyroid muscle, all intrinsic muscles of soft palate including levator veli palatiniThyroid cartilage, epiglottic cartilageVagus nerve X Superior laryngeal nerveRight 4th aortic arch: subclavian artery Left 4th aortic arch: aortic archSuperior parathyroid, ultimobranchial body which forms the Para follicular C-Cells of thyroid gland6thAll intrinsic muscles of larynx except the cricothyroid muscleCricoid cartilage, arytenoid cartilages, corniculate cartilageVagus nerve X Recurrent laryngeal nerveRight 6th aortic arch: pulmonary artery Left 6th aortic arch: Pulmonary artery and ductus arteriosusRudimentary structure, becomes part of the fourth pouch contributing to thyroid C-celts. See APPENDIX-2 below for Types of cartilagePinna or auricle is formed of elastic cartilage not fibrocartilage APPENDIX - 2Types of Cartilages Hyaline CartilageElastic CartilageFibrocatilageCompositionType II collagenChondroitin sulfateType II collagenElastin fibersType I collagenPerichondriumPresentPresentAbsent Articular cartilageArytenoid cartilageThyroid cartilageCricoid cartilageEpiphyseal growth plateNasal septumCostal cartilage of ribsAuricleAuditory tubeEpiglottisCuneiform cartilage of larynxEpiglottisExternal auditory canalArticular discsIntervertebral discsMenisciPubic symphysisGlenoid labrumAcetabular labrum 