<prompt> Diaphragm is developed from -EctodermEndodermSeptum secundumSeptum transversum  <response>: Ans. is di.e., Septum transversum Development of diaphramo Diaphragm develops from 4 structures derived from mesoderm which unite to form a sheet.1 Septum transversum Gives origin to sternal part and central tendinous region.2 Pleuroperitoneal membrane Dorsal paired portion.3 Dorsal mesentry of oesophagus Gives origin to crural part Dorsal unpaired portion.4 Lateral body walls from cervical myotomeGives origin to peripheral costal portion of diaphragm. 