MCQ IN MEDICINE

Detailed explanation-1: -The absorption of most dietary iron occurs in the duodenum and proximal jejunum and depends heavily on the physical state of the iron atom. At physiological pH, iron exists in the oxidized, ferric (Fe3+) state. To be absorbed, iron must be in the ferrous (Fe2+) state or bound by a protein such as heme.

Detailed explanation-2: -Iron is take up into the duodenal enterocyte on the apical membrane via DMT1 and is stored or exported during its life span of a few days (Fig. 3). If iron retained within the enterocyte is no exported, it will be lost as duodenal enterocytes are shed in the gastrointestinal tract.

Detailed explanation-3: -Liver-derived, circulating HEPC regulates duodenal iron absorption and also modulates iron release from stores in hepatocytes and RE macrophages (which recycle iron from senescent erythrocytes).

Detailed explanation-4: -Intestinal mucosal cells in the duodenum and upper jejunum absorb the iron. The iron is coupled to transferrin (Tf) in the circulation which delivers it to the cells of the body.