2023 MBBS EMBRYOLOGY RESPIRATORY SYSTEM.ppt

LECTURE NOTE BY ORISH CHINNA DEPARTMENT OF ANATOMY UNIPORT, RIVERS STATE  RESPIRATORY SYSTEM 4TH WK---- { ENDODERMAL ORIGIN}  FORMATION OF LUNG BUD – 4TH WK Appearance of resp diverticulum(lung bud) at ventral wall of foregut Esophagotrachael septum Partions...

LECTURE NOTE BY ORISH CHINNA DEPARTMENT OF ANATOMY UNIPORT, RIVERS STATE  RESPIRATORY SYSTEM 4TH WK---- { ENDODERMAL ORIGIN}  FORMATION OF LUNG BUD – 4TH WK Appearance of resp diverticulum(lung bud) at ventral wall of foregut Esophagotrachael septum Partions resp. Diverticulum into Ventral portion Dorsal portion (Resp primordium) { Oesophagus} DIAGRAM  LUNG DEVPT. CONTD Respiratory primordium Forms Lung buds Developes into Trachea & 2 bronchi (R& L) { at the end of 5th wk} RIGHT bronchi (10 ) LEFT bronchi(primary) ( Forms) 3sec bronchi @ sec bronchi @ 2lobes 3lobes  LUNG DEVPT CONTD. SECONDARY BRONCHI Further development 10 TERTIARY bronchi( R) ; 8 ON THE ( L) Creating BRONCHOPULMONARY SEGMENT DIAGRAM 1A DIAGRAM 1B  4 STAGES OF LUNG MATURATION PSEUDOGLANDULAR PERIOD CANANICULAR PERIOD TERMINAL SAC OR PRIMITIVE ALVEOLI PERIOD ALVEOLAR PERIOD  MATURATION OF THE LUNGS FORMATION OF PSEUDOGLANDULAR 6 -16WKS TERMINAL PERIOD BRONCHIOLES. NO RESP BRONCHIOLES CANALICULAR PERIOD 16-26WKS TERMINAL Note formation of type BRONCHIOLES 1 alveolar epithelial DIVIDES TO cells (,latter type 2 FORM{ Smaller which produces canals} surfactant) RESP.BRONCHIOLES & ALVEOLAR DUCTS TERMINAL SAC OR 26WKS TILL BIRTH FORMATION OF PRIMITIVE ALVEOLI TERMINAL PERIOD SAC(primitive alveoli) CAPPILARIES ESTABLISH CLOSE CONTACT (for  MATURATION OF THE LUNGS PSEUDOGLANDULAR 6 -16WKS FORMATION OF PERIOD TERMINAL BRONCHIOLES. NO RESP BRONCHIOLES ANALICULAR PERIOD 16-26WKS TERMINAL Note formation of type BRONCHIOLES alveolar epithelial DIVIDES TO ells (,latter type 2 FORM{ Smaller which produces canals} urfactant) RESP.BRONCHIOLES & ALVEOLAR DUCTS ERMINAL SAC OR 26WKS TILL BIRTH FORMATION OF RIMITIVE ALVEOLI TERMINAL ERIOD SAC(primitive alveoli) CAPPILARIES ESTABLISH CLOSE CONTACT (for DIAGRAM 1(best diagram) CANANICULAR PERIOD 1 Type I pneumocytes 2 Type II pneumocytes 3 Capillaries DIAGRAM 2 DIAGRAM 3 THE END