Fish and other aquatic creatures

What is the heart of fish? Fish Heart Chambers


When moving through blood vessels, the substance is exchanged between it and the tissues of the body. The vascular bed is very long and has many branches that interfere with normal blood flow. So, to overcome the entire path, it is necessary to set a certain pressure, and it is the heart that creates it.

The structure of this organ in fish is easier than in terrestrial animals. Knowing how many chambers of the heart are in fish and in other creatures, a comparative analysis can be made. It will allow you to visually see the differences and similarities of their cardiovascular system.

How many fish have heart chambers?

The heart of fish has a small weight, only 0.1% of the mass of their body, although there are exceptions to this rule. And many from school times remember how many chambers of the heart of fish are. Only two - the atrium and ventricle. But they have structural differences. According to the general scheme, there are two types that have similarities and differences.

Both options have four cavities:

  • venous sinus
  • valvular atrium,
  • ventricle,
  • Some kind of education, in its structure resembling the aortic arch.

The plate-wooded has an arterial cone, while the bony has an arterial bulb. The difference of these schemes lies in the morphofunctional features of arterial formations and ventricles. In the first case, the fish have fibrous tissue without valves. In fishes belonging to the plate-like, the arterial cone contains muscle tissue and a system of valves.

Knowing all this, everyone will know how many chambers of the heart are in fish, and what is their structure. Of particular interest is the structure of the myocardium, as it is represented by a homogeneous cardiac tissue. It is thinner than other animals.

Heart work

By how many chambers the heart of fish has, it is possible to determine the principle of this organ’s work and its rhythms. Heart rate (HR) is determined by many factors, including water temperature and fish age.

For clarity, it is proposed to consider the heart rate of carp at room temperature water.

Scientists have concluded that the frequency of contractions is strongly influenced by water temperature. The colder in the pond, the slower the heart beats. So, at a temperature of 8 ° C, the heart rate is about 25 beats per minute, and at 12 ° C - 40 beats.


Knowing what the heart of the fish and how many cameras in it, you can imagine the number of circles of blood circulation in them. Due to the fact that there are two chambers, the fish have only one circulation, although blood circulates through it for a long time. It takes about two minutes to complete a full circle, and a person’s blood passes two rounds in 23 seconds.

The movement of blood from the ventricle begins. From there, it enters through the bulb or arterial cone into the abdominal aorta. The blood is divided into two channels, diverging to the gill petals. Two arterioles depart from the leaf artery, which form the capillary network. It merges into one outgoing arteriole, and it passes into the outgoing petal artery. The latter form the right and left outgoing gill arteries.

The carotid arteries extend to the head, and the gill form the spinal aorta, which runs along the entire vertebra of the fish. Passing all over the body, the blood returns to the heart through the venous channel to the venous sinus. The structure of the heart of fish allows you to pump only venous blood. Passing through the gill apparatus, venous blood exchanges gases with water.

The vessels of the circulatory system of fish have a valve apparatus. It prevents the passage of blood through the channel. The uniformity of its movement is ensured by an even filling of the heart, without sharp fluctuations that are observed in humans.

Important body

The heart is the main and main organ of any circulatory system. Fish, like humans and other animals, have a heart. This may seem strange, because fish are cold-blooded animals, unlike us. This body is a muscle bag, which is constantly shrinking, thereby pumping blood throughout the body.

What is the heart of the fish and how is the movement of blood, you can learn by reading the information in this article.

Body size

The size of the heart depends on the total body weight, so the larger the fish, the greater its "motor". Our heart is compared with the size of the fist, the fish have no such possibility. But as is known from biology lessons, a small fish has a heart of only a few centimeters. But among large representatives of the underwater world, the body can even reach twenty to thirty centimeters. These fish include catfish, pike, carp, sturgeon and others.

Where is the heart?

If someone cares about the question of how many hearts a fish has, we will immediately reply - one thing. It is surprising that this question may arise at all, but as practice shows, it can. Very often, when cleaning fish, housewives do not even suspect that they can easily find the heart. Like humans, the heart of the fish is located in the front part of the body. If, to be more precise, then right under the gills. On both sides of the heart is protected by ribs, like ours. In the figure that you see below, the main organ of the fish is designated number one.

Considering the peculiarities of fish respiration and the presence of gills in them, the heart is different in structure than in terrestrial animals. Visually, the heart of the fish is similar in shape to ours. A small red pouch, with a small pale pink pouch from below, is the organ.

The heart of cold-blooded aquatic inhabitants has only two chambers. Namely, the ventricle and atrium. They are located in close proximity, and to be more precise, one above the other. The ventricle is located under the atrium and is distinguished by a lighter shade. Fish have a heart consisting of muscle tissue, this is due to the fact that it acts as a pump and is continuously reduced.

Circulation of blood

The heart of the fish connects to the gills with the help of the arteries, which are located on both sides of the main abdominal artery. It is also called the abdominal aorta, in addition, thin veins through which blood flows to the atrium from the whole body.

The blood of fish is saturated with carbon dioxide, which must be recycled as follows. Passing through the veins, blood enters the heart of the fish, where it is pumped through the arteries to the gills through the atrium. The gills, in turn, are equipped with many thin capillaries. These capillaries pass through all the gills and help to quickly transport pumped blood. After that, it is in the gills that carbon dioxide mixes and changes to oxygen. That is why it is important that the water where the fish live is saturated with oxygen.

Oxygenated blood continues its journey through the body of the fish and goes to the main aorta, which is located above the ridge. From this artery, many capillaries are branched off. They begin the circulation of blood, more precisely, the exchange, because as we remember, the blood returned from the gills, saturated with oxygen.

The result is a replacement of blood in the body of the fish. Blood from the arteries, which usually looks rich red, changes to blood from the veins, which is much darker.

Blood circulation direction

The chambers of the heart of fish are the atrium and ventricle, which are equipped with special valves. It is precisely due to these valves that blood moves only in one direction, excluding the return throw. It is very important for a living organism.

Veins send blood to the atrium, and from there it flows to the second chamber of the heart of the fish, and then to the special organs - the gills. The last movement occurs through the main abdominal aorta. Thus, it can be seen that the heart of the fish makes many endless cuts.

Heart cartilage fish

This special class of fish, which is characterized by the presence of the skull, spine and flat gills. The most famous representative of this class can be called sharks and stingrays.

Like their cartilaginous congeners, the heart of cartilaginous fish has two chambers and one circulation. The process of exchanging carbon dioxide for oxygen occurs in the same way as described above, with only a few features. These include the presence of a sprinkler, which helps the water to get into the gills. And all because the gills of these fish are located in the abdominal area.

Another distinctive feature can be considered the presence of such an organ as the spleen. She, in turn, is the terminal stop of blood. This is necessary so that at the moment of special activity there is a quick feed of the latter into the right organ.

The blood of cartilaginous fish is more saturated with oxygen, due to the large number of red blood cells. And all because of the increased activity of the kidneys, where they are produced.

Verified Answer

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Two-chamber heart. The ventricle pushes blood through the arteries. The blood in the atrium accumulates; when its volume becomes sufficient, it is pushed into the ventricle. One circle of blood circulation. The blood during contraction of the ventricle is pushed into the aorta. Then it enters the vessels, and then into the spinal aorta. After that, the blood is sent to the organs and tissues. Ends the circle of blood circulation in the atrium.

Four-chamber heart. The right atrium accumulates blood from the superior and inferior vena cava. The right ventricle pushes blood into the pulmonary artery. 4 pulmonary veins flow into the left atrium. The left ventricle pushes blood into the aorta. Two circles of blood circulation, large and small. Big: left ventricle-aorta-artery-internal organs and vein cells-right atrium. Small: right ventricular-pulmonary arteries-lungs-pulmonary veins left atrium.

Four-chamber heart. The right atrium accumulates blood. The right ventricle pushes blood into the pulmonary artery. The left atrium pushes blood into the left ventricle. The left ventricle pushes blood into the aorta. Two circles of blood circulation. Small from the right ventricle to the left atrium. Large from the left ventricle to the right atrium.

Three-chamber heart (except crocodiles, they have 4 cameras). Two atria, one ventricle. Blood from the right atrium enters the ventricle of the heart and is retained in its right side by a septum, arterial blood from the left atrium is released into the left part of the ventricle. Two circles of blood circulation.

Three-chamber heart. Arterial blood enters the left atrium from the lungs, and mixed blood enters the right atrium, and arterial blood from the skin veins. Two circles of blood circulation.