The anatomy of the diaphragmatic circulation was found to be composed of an internal arterial circle formed by the head to head anastomosis of the phrenic arteries and internal mammary arteries. Branches originating from the internal arterial circle anastomosed head to head with branches of the intercostal arteries (8$ sp{ rm th}$ to 13$ sp{ rm th}$ intercostal space) to form costophrenic arcades all along the muscular fibers of the crural and costal diaphragm. These anastomosis were found to be physiologically functional. Diaphragmatic circulation produced only by the intercostal arteries was able to sustain costal and crural contractility at the fatigue threshold (TTdi of 0.20). However, internal mammary artery perfusion was only able to maintain costal contractility. Left and right hemidiaphragmatic arterial communications (shunting) were inexistant during electrophrenic unilateral and bilateral stimulation. Diaphragmatic venous outflow was produced mostly by the intercostal veins (60% of total diaphragmatic venous outflow) which drained into the azygos trunk. The phrenic veins contributed 25% and the internal mammary veins contributed 15% of total diaphragmatic venous outflow. Diaphragmatic circulation was found to be proportional to the Pdi and was related to the duty cycle by a parabolic function with the highest flow rates being observed at a duty cycle of 0.50, regardless of the Pdi being generated.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41053 |
| Date | January 1991 |
| Creators | Comtois, Alain Steve |
| Contributors | Grassino, Alejandro (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001482645, proquestno: NN94602, Theses scanned by UMI/ProQuest. |
Page generated in 0.0015 seconds