Evolution and functional differentiation of the diaphragm muscle of mammals

Matthew J. Fogarty, Gary C. Sieck

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


Symmorphosis is a concept of economy of biological design, whereby structural properties are matched to functional demands. According to symmorphosis, biological structures are never over designed to exceed functional demands. Based on this concept, the evolution of the diaphragm muscle (DIAm) in mammals is a tale of two structures, a membrane that separates and partitions the primitive coelomic cavity into separate abdominal and thoracic cavities and a muscle that serves as a pump to generate intra-abdominal (P ab ) and intrathoracic (P th ) pressures. The DIAm partition evolved in reptiles from folds of the pleural and peritoneal membranes that was driven by the biological advantage of separating organs in the larger coelomic cavity into separate thoracic and abdominal cavities, especially with the evolution of aspiration breathing. The DIAm pump evolved from the advantage afforded by more effective generation of both a negative P th for ventilation of the lungs and a positive P ab for venous return of blood to the heart and expulsive behaviors such as airway clearance, defecation, micturition, and child birth.

Original languageEnglish (US)
Pages (from-to)715-766
Number of pages52
JournalComprehensive Physiology
Issue number2
StatePublished - Apr 2019

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)


Dive into the research topics of 'Evolution and functional differentiation of the diaphragm muscle of mammals'. Together they form a unique fingerprint.

Cite this