The greater omentum is now recognized as an important organ in the fight against intra-abdominal infections, so it is often called the “policeman of the peritoneal cavity”. The greater omentum plays the most important role in the implementation of immune supervision of the antigenic condition of the peritoneal fluid and rapid response of damage to the gastrointestinal tract, which is often complicated by inflammation of the peritoneum – peritonitis. The purpose of the work was to study the peculiarities of the structure of the greater omentum of white rats and its role in peritonitis by means of a bibliographic analysis of the literature. Materials and methods. This bibliographic analysis is based on published articles, books, textbooks, monographs and dissertation abstracts. For the purposes of this systematic review, a literature search was carried out in the worldwide Internet, domestic sources of literature, scientific and electronic library of Poltava State Medical University using the following key words: “morphology”, “comparative anatomy”, “greater omentum”, “greater omentum of the rats”, “immune system”, “white rats”, “laboratory animals”, “rat anatomy”, “peritonitis”. Results and discussion. The greater omentum of white rats and humans are represented by two different structures: translucent membranous regions and regions rich in adipose tissue. According to the literature, the greater omentum of white rats is the main morphological characteristic (in miniature), homologous to the human one. The main function of the greater omentum, according to the opinion of many authors and ours too, is immunity. Immune structures of the greater omentum of white rats are represented by lymphoid nodules, known in the literature as milky spots, most of which are located near arteries and veins. In pathological conditions, the greater omentum acquires absolutely special properties, such as plasticity, the ability to fuse with a traumatic and inflamed surface, the ability to hemostasis and phagocytosis, the ability to germinate and revascularize, to absorb fluids and microparticles from the peritoneal cavity, and the ability to the immunological response. Conclusion. According to the literature, the greater omentum of white rats is a miniature likeness of the greater omentum of a person. However, unlike the latter, it consists of only one duplication of the visceral peritoneum, between the leaves of which there are blood vessels with deposits of adipose tissue and milk spots. Thus, the greater omentum of white rats is a perfectly acceptable object of experimental research with the subsequent legitimate extrapolation of their results to humans. The greater omentum occupies a central place in the peritoneal defense mechanisms due to its innate immune function, high absorbing capacity, and ability to attach to neighboring structures to close defects of abdominal organs and promote their healing, due to its expressive angiogenic activity

Keywords: greater omentum, milky spots, peritonitis, white rats

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