Ryabushko O. Peculiarities of the gallbladder structure in humans and animals in comparative anatomical aspect

The research devoted to revealing the features of the structural components of the gallbladder wall of a man and representatives of different classes of animals depending on the natural type of nutrition. It has been established that the wall of fish gall bladder which consists of the mucous membrane, the muscular and adventitious membranes, are characterized by flask-shaped and pear-shaped forms. The mucous membrane is most expressed in the neck of the gallbladder of herbivorous fish, and less in the neck of the bladder of predatory fish, where it forms single, low folds of the mucosa. The widest will be the adventitious and muscular membranes of the wall. The birds are characterized by a flask-shaped, cylindrical and pear-shaped gallbladder. A more complex structure of the structural components of the wall is characteristic of herbivorous birds, in which the mucosa on all sites forms a large number of folds of different heights and has the largest thickness in the body of the gallbladder. The muscular membrane is well developed, formed by two layers of smooth muscle fibers. Predatory birds are characterized by a more simplified structure of the gallbladder wall, this is evidenced by a decrease in the thickness of the mucosa of neck wall and decrease in the height and number of its folds. In mammals, pear-shaped and flask-shaped forms of the gallbladder predominate. A mucous membrane of herbivorous mammals, greatly thick at the bottom, forms numerous folds where anastomoses occur, contains a multitude of vessels of the microcirculatory bed, small lymph nodes and mucous glands. In omnivorous animals, the mucous membrane forms low, but wide folds, from the top to the base of which the blood vessels pass. In carnivorous animals, the mucous membrane does not contain lymphoid structures and mostly expressed in the body of the gallbladder. Pear-shaped form of the gallbladder is more typical for humans. At the area of the bladder’s bottom and body, the relief of the mucous membrane is similar to the relief of herbivorous mammals. Structurally the muscular and adventitious walls of the gallbladder are most similar to the wall of the omnivores bladder. The wall of the human gallbladder, as well as herbivorous and omnivorous mammals, contains lymph nodes and mucous glands. Most differences are observed in the structural components of the gallbladder wall in humans and carnivorous mammals.