Constrictions of esophagus when measured from upper incisiors are present at
**Core Concept**
The esophagus has three main constrictions that are important anatomically and clinically. These constrictions are narrowing points where the esophagus can be easily compressed or obstructed.
**Why the Correct Answer is Right**
The correct answer is related to the anatomical locations of these constrictions, which are: the first constriction at the cricopharyngeal sphincter (upper esophageal sphincter), the second at the aortic arch, and the third at the lower esophageal sphincter (near the diaphragmatic hiatus).
**Why Each Wrong Option is Incorrect**
**Option A:** This is not the correct location for any of the main constrictions of the esophagus.
**Option B:** Similarly, this does not correspond to the recognized anatomical locations of esophageal constrictions.
**Option C:** This option is also incorrect as it does not accurately represent the location of the esophageal constrictions.
**Clinical Pearl / High-Yield Fact**
It's crucial to remember that the constrictions of the esophagus are at approximately 15 cm (cricopharyngeal), 22-25 cm (aortic arch), and 37-40 cm (diaphragmatic hiatus) from the upper incisors, as these are key points for understanding esophageal pathology and intervention.
**Correct Answer:** Correct Answer: C. 22-25 and 37-40 cm from upper incisors.