right crus
The right crus is the part of the diaphragm that takes origin from L1-L3. It splits to enclose the esophagus. So, in the case of an esophageal hernia, the herniating stomach would be entirely surrounded by the fibers of the right crus. The left crus is the part of diaphragm that takes origin from L1 and L2. It is smaller and shorter than the right crus, and it intermingles with the right crus around the aortic hiatus. It does not contribute to the esophageal hiatus. The central tendon is the tendon in the middle of the diaphragm where all the fibers of the diaphragm attach. It provides an opening for the inferior vena cava. Finally, sternal and costal fibers refer to muscle fibers in the diaphragm that take origin from the xyphoid process or the ribcage. This could not refer to the right crus, since it originates on the lumbar vertebrae.