upper 1/3rd of oesophagus is supplied by ?
**Core Concept**
The esophagus is divided into three parts based on its blood supply, and understanding these regions is crucial for various clinical procedures, including anesthesia and surgical interventions. The upper 1/3rd of the esophagus receives its blood supply from a distinct set of branches.
**Why the Correct Answer is Right**
The upper 1/3rd of the esophagus is primarily supplied by branches from the inferior thyroid artery, which arises from the thyrocervical trunk. These branches include the esophageal branches that supply the upper esophageal sphincter and the adjacent mucosa. The blood supply to this region is relatively consistent and is important for procedures such as esophageal dilation or biopsy.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the lower 1/3rd of the esophagus is actually supplied by branches from the left gastric artery, not the upper 1/3rd.
**Option B:** This option is incorrect because the middle 1/3rd of the esophagus is supplied by branches from the broncho-oesophageal arteries, which arise from the aortic arch, not the upper 1/3rd.
**Option C:** This option is incorrect because the entire esophagus is supplied by branches from the descending aorta and other arteries, but this is not specific to the upper 1/3rd.
**Clinical Pearl / High-Yield Fact**
When performing anesthesia or surgical procedures in the upper esophagus, knowledge of the blood supply is crucial to avoid complications such as bleeding or esophageal perforation.
**Correct Answer: C. The broncho-oesophageal arteries which arise from the aortic arch supply the middle 1/3rd of the oesophagus, but the lower 1/3rd is supplied by the left gastric artery and the upper 1/3rd is supplied by the inferior thyroid artery.**