Types of circulatory systems
There are two types of circulatory systems:
closed circulatory system: It consists of a series of blood vessels which, without leaving them, travels blood. The material carried by the blood reaches the tissues through diffusion. It is characteristic of annelids , molluscs and cephalopods vertebrates.
open circulatory system: The blood pumped by the heart travels through blood vessels, which supplies blood directly to cells and then returned by different mechanisms. This type of system is presented in arthropods and molluscs cephalopods not .
blood circulation was discovered by the physician William Harvey .
fish Circulation
Full Circulation: Appears in fish. In the blood circulation only happens once through the heart at every turn. The heart is tubular and shows a venous sinus that collects the blood, an atrium and a ventricle impeller. The blood comes from the veins of the body charged with CO 2 to the heart. The ventricle pumps blood to the gills to get oxygen flowing through arteries and distributed throughout the body. The return of blood to the heart through veins is performed.
The brachial artery, carrying blood to the gills for oxygenation. Therefore, the circulation in these animals is closed, simple and complete, ie there is only one circuit and no mixing of blood.
amphibians Circulation
In the first vertebrate lungs (Amphibians and Reptiles no crocodiles) is the heart and thoracic position appears twice circulation, as there is a lower circuit or pulmonary vein that carries blood to the lungs and bring back arterial blood to the heart from those, and the circuit greater or general, blood that carries blood to the body and brings back the venous blood to the heart.
In these animals the heart has three cavities : two atria (right and left) and a single ventricle, rather muscular. The right atrium receives venous blood from the body, and sends it to the ventricle to the pump to the lungs through the pulmonary artery. The left atrium receives arterial blood from the lungs, and it sends the ventricle pumps blood to the body through the aorta. Between the two arteries there is a small tube called throw it through. The atria contract in succession, so that the mixture of blood in the ventricle is scarce. However, the double movement will be incomplete.
reptiles Circulation
Reptiles In crocodilians and there is a complete division of the ventricle in two compartments (right and left). Therefore, it is the heart and has two staffs tetraventricular Aortic left leaving the right ventricle and carries venous blood, and the right leaving the left ventricle and carries blood pressure. There is a very small mixing of blood in the descending aorta. Therefore, it is considered that the movement is incomplete.
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