Hello. This is Dr. Love.
1. The Z line is the area of transition from the usual lining of the esophagus to the usual lining of the stomach. When saying that it is irregular, that means that it is not a simple ring at the lower end of the esophagus, but rather that the line is more of a wave form with high and low sections. Saying that it is 36 cm from the incisors is a way of measuring the exact location measuring from the point where the endoscope passes the front teeth.
The fact that the Z line is irregular is not an issue, by itself, as an irregular Z line can be seen in about 10-15% of normal people. The distance from the incisors also is not an issue, by itself. It is more a point of reference. When comparing one endoscopy to another, a comparison of the distance from a first endoscopy to a subsequent endoscopy will provide information about whether the location of the line is changing over time.
2. The antrum is a portion of the stomach. Erythematous mucosa in the antrum refers to redness of the lining of that part of the stomach, which is most often related to inflammation (gastritis). The biopsy will confirm gastritis and address what type of gastritis is present.
3. The duodenum is the first part of the small intestine, which is all that can be seen by endoscopy, and your duodenum is normal.
If I can provide any clarification, please let me know.