Structures passing through the aoic hiatus of diaphragm are:
**Core Concept**
The aortic hiatus of the diaphragm is an anatomical opening that allows vital structures to pass from the thoracic cavity to the abdominal cavity. It is a crucial passage that enables the aorta, the thoracic duct, and the azygos system to communicate between the two cavities.
**Why the Correct Answer is Right**
The aortic hiatus is located at the level of T12-L1 vertebrae and allows the descending thoracic aorta to pass from the thoracic cavity to the abdominal cavity. The thoracic duct, which is responsible for draining lymph from the lower body, also passes through the aortic hiatus. Additionally, the azygos system, which includes the azygos vein and its tributaries, also traverses this opening.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it does not mention any of the structures that pass through the aortic hiatus.
* **Option B:** This option is incorrect as it mentions the esophageal hiatus, which is a separate opening in the diaphragm that allows the esophagus to pass from the thoracic cavity to the abdominal cavity.
* **Option C:** This option is incorrect as it mentions the caval opening, which is the opening through which the inferior vena cava passes from the abdominal cavity to the thoracic cavity, but not the aortic hiatus.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that the aortic hiatus is located at the level of T12-L1 vertebrae, which is a critical landmark for surgeons and anesthesiologists during thoracic and abdominal surgeries.
**Correct Answer: C. Aorta, thoracic duct, and azygos system.**