Cur why has the octopus three hearts? Evolutionary adaptation to unique physiology
The presence of three hearts in the octopus is not a quirk of nature, but a result of deep evolutionary adaptation, directly related to the peculiarities of its circulatory system and lifestyle. This unique cardiological configuration represents a highly effective solution to the problem of oxygen supply to a large and extremely active organism with a number of specific anatomical features. To understand the functional significance of this system, it is necessary to consider the composition and role of each heart in the context of the general physiology of the cephalopod mollusk.
Blood based on copper and its consequences for the circulatory system
The fundamental reason for the development of three hearts is the type of respiratory pigment in the octopus's blood. Unlike mammals, whose blood uses iron-containing hemoglobin, the blood of octopuses and other cephalopod mollusks is based on hemocyanin, where copper acts as the oxygen carrier. Hemocyanin is significantly less effective in binding and transporting oxygen than hemoglobin. When in contact with air, such blood takes on a characteristic blue hue. To compensate for this relative inefficiency, octopuses require a more powerful and specialized circulatory system capable of creating high pressure to ensure rapid delivery of oxygen to tissues.
Two branchial hearts: specialized pumps for efficient gas exchange
Two of the three hearts, known as branchial hearts (or branchial hearts), serve as pumps for the first stage. They are located at the base of each of the two gills. The main function of these hearts is to receive venous blood rich in carbon dioxide from the entire body and force it through dense capillary networks of the gills. This is a critically important process, as resistance in the thin gill vessels is very high. Without these specialized pumps, the main heart would not be able to cope with the load, and the blood flow t ...
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