Lung Development, Choanal Atresia, Lung Malformations & NRDS | First Aid 2026 | USMLE Step 1

Welcome to the Lecture 1 of Complete Respiratory System Series! 📖 First Aid 2026: Respiratory Embryology (Pages 678–679) This is the first lecture of the Respiratory System series, covering Respiratory Embryology from First Aid. In this video, you'll build a strong conceptual foundation by understanding lung development, congenital respiratory anomalies, alveolar cell biology, surfactant physiology, and neonatal respiratory disorders—topics that are repeatedly tested in USMLE Step 1, USMLE Step 2 CK, MBBS, FCPS Part 1, NRE, NEET PG, PLAB, MRCP, AMC, residency entrance exams, and medical school exams. 📚 Topics Covered • Lung Development Respiratory diverticulum Lung bud formation Five stages of lung development Embryonic stage Pseudoglandular stage Canalicular stage Saccular stage Alveolar stage Surfactant development Clinical correlations • Choanal Atresia Clinical presentation Diagnosis CHARGE syndrome High-yield exam points • Lung Malformations Pulmonary hypoplasia Diaphragmatic hernia and Potter's sequence Bronchogenic cysts Clinical correlations • Alveolar Cell Types Type I pneumocytes Type II pneumocytes Alveolar macrophages Club cells Pores of Kohn Law of Laplace Surfactant composition and functions Hemosiderin-laden macrophages • Neonatal Respiratory Distress Syndrome (NRDS) Pathophysiology Ground-glass appearance Risk factors Screening tests for fetal lung maturity Treatment Oxygen therapy complications Retinopathy of prematurity, Intraventricular hemorrhage, Bronchopulmonary dysplasia Important USMLE pearls 📖 How to Study This Lecture • Read First Aid 2026 Respiratory Embryology (Pages 678–679) before starting. • Watch the lecture without taking notes on your first pass. • Avoid distractions and focus on conceptual understanding. • Pause whenever instructed, revise the corresponding First Aid pages, then continue the lecture. • You may watch the lecture at 1.2× speed if comfortable. 📺 This lecture is part of the Complete Respiratory System Series, where every First Aid topic is explained conceptually with integration of anatomy, physiology, pathology, pharmacology, embryology, microbiology, and clinical correlations. 👍 If you found this lecture helpful, please Like, Subscribe, Share, and turn on the notification bell so you never miss the upcoming Respiratory System lectures. #pulmonology #firstaidusmle #usmlestep1guideforpakistanistudents #pathology #neetpg #usmlestep1lectures #medicalstudent #selfless #medical #mbbs #fcps #usmle