All about the circulatory system of animals


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The circulation has the task of transporting nutrients and oxygen to the cells and collecting waste products and carbon dioxide. A process that occurs in all animals, so we explain to you now all about the circulatory system of animals.


All about the circulatory system of animals

the the circulatory or cardiovascular system is the set of organs responsible for the transport of different fluids, such as blood and, more generally, lymph, whose main task is to provide the cells of the body with the elements necessary for their survival. the circulatory system is also primarily responsible for oxygen transport to body cells living beings. However, there are circulatory systems adapted to each type of organism, according to their characteristics. basically the invertebrates children have a circulatory system open. However, the most complex systems are found in the types of circulatory systems farm. Now we will analyze what each is based on.

free movement

In this type of circulation, the body has no true heart pump blood. The pumping system is made by contractions blood vessels. The system is therefore very slow, This is because the animal has to constrict the blood vessels through the muscles.

Animals that have this circulatory system also don’t have blood as such. Rather, it is a liquid composed of hemolymph Yes some blood.

However, the main characteristic of this circulatory system is the ability of blood to to go out of the blood vessels Yes bath all organs of the body.

The consequence of all this is that animals which present this type of circulatory system are small and with a very low metabolism. That is to say, your breathing, your digestion and your ability to move are very slow. It usually occurs in most arthropods and molluscs.

closed circulation

found in animals vertebrates, although some invertebrates also exhibit them (the so-called higher vertebrates, such as squid and octopus). It is the system that is in the human organism.

The characteristics of this circulatory system are that the animal has the ability to transportation nutrients and oxygen through a system complex formed by a heart who pumps and blood vesselsformed by veins, arteries and as lower branches, capillaries.

It is called a closed system because the blood is contents in the blood vessels and has no chance of free flow by other organisms as in the previous case of closed circulation.

Organisms that have this system are more quicksince the system itself is faster and the blood pressure is much higher due to the pumping of the heart.

It should also be added that animals working with this type of circulation need remove waste in another way quickly done. Thus, it can be seen that each type of circulatory system has its own advantages and disadvantages.

In the closed circulation we have several subtypes, depending on the animal.

simple closed circulation

Simple circulation is typical of fish. In his case, the heart has a curved shape and is formed by a atrium and one ventriclealso has a venous sinus or accessory chamber.

This structure allows your way of working to be one way. The blood spell of the heart following a contraction of the ventricle, is carried by a blood vessel called the dorsal aorta. From there it goes directly to gillswhere is oxygen. After that, the blood is transported and distributed throughout the body. give up oxygen and capture dioxide of carbon and returns to the venous sinus of the heart by veins.

That is, the differentiating characteristic of this circulatory system is that the blood does not passes through the heart once per cycle. The heart, in simple circulation systems, never pump oxygenated blood. It expels only deoxygenated blood.

closed double circulation

It’s the animals vertebrates that work through lungs. In the lungs there is a gas exchangeblood redeems oxygen for him carbon dioxide. The main animals that have this system are amphibians, reptiles, birds and mammals.

This system operates on a double meaning. On the one hand, the blood oxygen it travels from the lungs to the various organs. Once this first phase is over, the blood returns to the lungs with carbon dioxide.

It is basically called a double circulation because the blood passes twice by the heart in the same respiratory cycleonce to go to lungs (carrying carbon dioxide) and the second time with the intention of going to the rest of the body charged with oxygen. But all does not stop there, within the closed double circulation we can find two other sub-types: the complete closed double circulation and the incomplete closed circulation.

incomplete circulation

It is a type of circulation farm Yes double. The main characteristic of incomplete blood circulation is the mixing oxygenated blood with blood returned with carbon dioxide.

The meeting place is heart. Unoxygenated blood comes from other parts of the body and oxygenated blood logically comes from the lungs. For this reason, the hearts of living organisms that exhibit this type of circulatory system have only a single ventricle.

full circulation

Like the incomplete, it is a type of closed and double circulation, in this case the oxygenated blood at no time does it mix with deoxygenated blood from other organs of the body.

Circulatory system in invertebrates

When analyzing the circulatory system in invertebratesthey must be analyzed in different groups, since each has its particular characteristics:

Porifera, cnidarians and flatworms

These three invertebrate groups do not have a circulatory systemeach has its own particularities:

Sponge circulatory system

  • poriferous – When it comes to obtaining nutrients and oxygen, sponges do so by exchanging substances with the environment in which they live.
  • cnidarians – In this case, jellyfish also exchange substances but by diffusion
  • flatworms – They also resort to diffusion, through the gastrovascular cavity with which they have

molluscs and annelids

The molluscs They have an open circulatory system. By having a multi-chambered heart, they can send hemolymph into open spaces. From there it passes through the veins, the gills and returns to the heart.

snail circulatory system

This is how molluscs work, except in the case of cephalopods. And it is that squids, octopuses, cuttlefish and others have a closed circulatory system and gill hearts that facilitate blood oxygenation

For their part, the annelids They have a closed circulatory system, with a dorsal vessel and a ventral vessel communicating with each other. The rate of contraction is constant and in cases such as worms they add larger cross vessels which serve as the heart.

arthropods and echinoderms

If we talk about the arthropods, their circulatory system is open. Its tubular heart is enclosed in a pericardial cavity pierced with holes called ostioles. Thus, the hemolymph crosses the arteries, crosses all its tissues, until it returns to the heart through the ostioles.

spider circulatory system

In the case of shellfish, before returning to the heart, the hemolymph passes through the gills. Whereas, in the case of insects, hemolymph does not carry oxygen, only nutrients and wastes.

Finally, the echinoderms They have an open but very small circulatory system. In fact, most of the circulation is ensured by the ambulacral system which has its origin in the hemal.

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