The structure of the human abdominal cavity is very different from the structure of similar anatomical structures in other species of mammals. The abdominal cavity (cavum abdominis) or the abdominal cavity is called the space lined by the intraperitoneal fascia, bounded above by the leaf of the diaphragm, on both sides and in front by the wide muscles (musculi obliqui et transversus abdominis) of the abdomen, and behind - by the lumbar spine and the muscles adjacent to it . Below it, that is, an abdominal or abdominal cavity, smoothly passes into a small cavity of the small pelvis. In the abdominal space there are various internal organs together with the peritoneum covering them, as well as large vascular trunks and nerves.
The structure of the abdominal cavity of a person is studied in detail in higher medical schools, since diseases of the organs located in it are the most common pathological conditions in medical practice. It is from the surgeon’s deep knowledge of such a feature of the human body as the structure of the abdominal cavity that the life of more than a dozen patients in need of it sometimes depends.
The structure of the organs of the human abdominal cavity is characterized by the fact that most of them are covered with a thin serous membrane called the peritoneum. The peritoneum is a delicate and very thin connective tissue structure, which has a huge number of differentiated elastic fibers and is covered inside by a single-layer flat epithelium, i.e., mesothelium. This thin serous membrane has a large and very peculiar suction ability. Serous fluid, which is sufficiently produced by the peritoneal mesothelium, lubricates the surface of all internal organs, facilitating their friction with each other. Due to this unique property of the peritoneum, a healthy person does not feel discomfort or any changes in his own abdominal cavity. However, with inflammatory phenomena, when a foreign effusion falls on the sheets of the peritoneum, there is a feeling of sharp and ongoing pain. In inflammatory processes, the peritoneum is able to form adhesions to limit the spread of infection throughout the abdominal cavity.
The structure of the human abdominal cavity is the same in each of the representatives of Homo sapiens. It alone may differ slightly in different periods of his life. In childhood, it has its own characteristics, in adulthood - its own. There are also some differences between the male and female abdominal cavities. For representatives of the strong half, this cavity is an enclosed space, and for the female part of the population it is not such, because it connects with the uterine cavity through the fallopian tubes, and through the vagina with the surrounding environment.
Organs in the abdominal or abdominal cavity can be covered with a serous membrane either on all sides, or only partially. Some of them are not covered by the peritoneum at all. The peritoneum that lines the walls of the abdomen is called the parietal peritoneum, that is, the parietal, and the one that lines most of the internal organs is called the visceral or visceral peritoneum. Therefore, speaking in general, we can say that the structure of the human abdominal cavity is nothing more than a slit-like space between the sheets of the parietal (parietal) and visceral (internal) peritoneum, filled with a small amount of aseptic serous fluid.
The following parts are also distinguished in the peritoneum, which are called mesentery. The mesentery, or duplicate, is a bifurcated sheet of the peritoneum, on which the small intestine without the duodenum, the appendicular process, the transverse and sigmoid parts of the colon of the large intestine are suspended from the abdominal cavity .