Overview Diaphragm derived from 4 different sites septum transversum (located between primitive heart and liver) → central tendon pleuroperitoneal folds body wall→ peripheral parts of diaphragm dorsal mesentery of esophagus → crura diaphragm descends during development and becomes innervated on week 4 of development by the phrenic nerve C 3, 4, 5 Herniations Congenital diaphragmatic hernia failure of the pleuroperitoneal membrane to develop abdominal contents herniate into the pleural cavity contents can compress lungs buds preventing proper development causing pulmonary hypoplasia commonly presents on left posterolateral side Symptoms in newborn flat abdomen dyspnea bowel sounds in chest area cyanosis Esophageal hiatal hernia stomach herniates through esophageal hiatus due to the elevated level, esophagogastric sphincter does not work properly "acid reflux" in adults infants typically vomit when laid down after feeding