A literal translation of his name from Latin is "I place between", Which reflects the role of the newly discovered organ - interstitium. How did it happen that it had previously eluded anatomists? What functions does it perform in the human body?
An organ (or organ) is called a collection of tissues that perform a similar function. Until 2017, anatomists were convinced that 79 different organs are present in the human body. In January last year, it was recognized that the eighty human body is a keddle, a thin peritoneal membrane, the role of which is to fix the viscera to the abdominal cavity. This year, it was discovered that there are 81 organs in the human body - and the last discovered is one of the largest. His explorers, scientists from the NYU School of Medicine, the University of Pensylvania and Mount Sinai Beth Israel Medical Center, called him an interstitium, which means "placed between”.
If it is considered one of the largest organs, how did it happen that it has not been noticed yet? It turns out that everything is to prepare preparations for examination under a microscope.
Flexible sponge
The entire history of the discovery began with Israeli scientists: Dr. David Carr-Locke and Dr. Petros Belias and their patient, who was looking for cancer metastases. Traditionally, the methods of histopathological examination consist in the microscopic observation of a dead specimen taken from the patient. However, in the case of an Israeli patient, a modern technology of confocal laser endomicroscopy was used, which allows the observation of still living tissues.
Among the various samples taken from the patient, the researchers found one that looked damaged. There were small, empty spaces in it that scientists could not identify. It turned out that these were remains of sunken spaces that were filled with liquid early. With time, they began to notice these "sunken spaces" also in other samples. In a traditional study of a dead slice, fluid from these spaces leaked completely, and the remains of a flexible liquid-soaked sponge were generally recognized as remnants of connective tissue.
The researchers concluded that this previously unknown, flexible network of small spaces, filled with liquid, filled with fluid, is a new organ - the interstitium. It turned out that the so-called "spongy" interstitial fluid structure is extremely widespread in the human body. It occurs between the layers of the skin, is present in the lining of the intestines, surrounded by blood vessels or the bloodthills, separating the muscles from each other. Thanks to this, it can be said that it is one of the largest organs.
Long unknown, although important
It turns out that the flexible construction of a network of liquid-filled interstitium blebs is extremely important from the point of view of the human body. Thanks to the newly discovered organ, individual tissues do not break apart during the movement, and the fluid present in the interstitium absorbs the potential impact of, for example, the organs at each other during their work. The interstitial fluid itself moves very easily through the body, and through it the cancer cells can move so quickly between even distant parts of the body.
It is also believed that changes in the structure of collagen fibers, building the "sponge" of the interstitium, appearing during the aging of the body lead directly to the formation of wrinkles, hardening of tissues or stiffness of joints, observed in older people.
It is surprising that the interstitium, with its range of functions, has been hiding from our prying eyes for so long!
Based:
P. C. Benias et al.,Structure and Distribution of an Unrecognized Interstitium in Human Tissues. Scientific Reports 8 (2018) 4947
