Neural Crest | Migration, Hirschsprung, Waardenburg & DiGeorge | USMLE Step 1

Neural crest cells migrate from the developing neural folds to form peripheral ganglia, Schwann cells, melanocytes, adrenal medullary chromaffin cells, and major craniofacial and cardiac contributions. Connect each derivative to the clinical findings of Hirschsprung disease, Waardenburg syndrome, 22q11.2 deletion syndrome, and Treacher Collins syndrome. This lesson distinguishes conductive from sensorineural hearing loss, explains why TBX1-related pharyngeal signaling is more than an intrinsic neural crest defect, and clarifies modern mammalian evidence for the endodermal origin of thyroid C cells. It also reviews the cellular origins of melanoma, schwannoma, pheochromocytoma, and neuroblastoma. Companion review PDF and original practice questions: https://usmlefox.com/lesson/V061?utm_... Educational review for USMLE Step 1. This lesson is not individualized medical advice. #USMLE #Step1 #NeuralCrest #Embryology