UC San Diego News Center. Unsafe at Any Level: Very Low Blood Alcohol Content Associated With Causing Car Crashes. Even âminimally buzzedâ drivers are more often to blame for fatal car crashes than the sober drivers they collide with, reports a University of California, San Diego study of accidents in the United States.
The pleuroperitoneal membranes fuse with the dorsal mesentery of the esophagus and with the dorsal portion of the septum transversum to complete the partition between the pleural and peritoneal cavities. The membranes form the primitive diaphragm but end up as only a small portion of the fully developed diaphragm.The dorsal mesentery of the esophagus fuses with the two structures septum transversum and the pleuroperitoneal membranes to form the middle of the diaphragm.Other muscle fibers that grow into the dorsal mesentery of the esophagus will develop into the crura of the fully developed diaphragm.he first strucuture to become part of the diaphragm is the septum transversum, a mesodermal strucutre that forms the central tendon of the diaphragm. The septum transversum is identifiable at three weeks of gestation as a mass of mesoderm just posterior to the pericardial cavity, which contains the heart.
The origins of the diaphragm are found along the lumbar vertebrae of the spine and the inferior border of the ribs and sternum. Openings in the diaphragm allow the esophagus, phrenic and vagus nerves, descending aorta, and inferior vena cava to pass between the thoracic and abdominal cavities....hen we inhale, the diaphragm contracts and is drawn inferiorly into the abdominal cavity until it is flat. At the same time, the external intercostal muscles between the ribs elevate the anterior rib cage like the handle of a bucket. The thoracic cavity becomes deeper and larger, drawing in air from the atmosphere.