The circulatory system of birds, insects and arthropods

The circulatory system of birds has a striking difference from the circulatory system of reptiles: it has a complete separation of arterial and venous blood flow. A special feature of birds is their big heart. And in small birds, the size of the heart is larger, and the heartbeat is much more intense than that of large birds.

The blood pressure of birds is more than twice the number of reptiles and mammals. This also applies to the quantitative content of blood, hemoglobin, the total number of erythrocytes, and the sugar content, and also to the oxygen capacity of the blood. The circulatory system of birds has all these features due to the high level of metabolic processes. A large heart and a frequent pulse cause the accelerated circulation of blood in the system, which, combined with a large oxygen capacity and an increased amount of sugar, allows intensive and immediate saturation of tissues and all organs with nutrients and oxygen. This leads to the removal of products from the organs of the bird, resulting from metabolic processes.

The heart of a bird is four-chambered, consists of 2 auricles and 2 ventricles. In large veins, venous blood collects in the right atrium and flows into the right ventricle. The pulmonary artery departs from the right ventricle and then divides into the left and right branches. According to them, the venous blood tends to the lungs, where it is oxidized. Next, oxidized arterial blood moves through the veins into the left atrium. The circulatory system of birds has 2 circles of blood circulation (small and large). The large one consists of the left ventricle, the right arch of the aorta, the main artery, from which two arteries separate from the heart: the right and left nameless. She herself returns over the right bronchus along the spine, like the dorsal aorta. The arteries, each in turn, are divided into a drowsy, going to the head, and a large subclavian. The subclavian artery divides into a brachial one, directed into the muscles of the wing, and a powerful thoracic artery going into the muscles of the sternum.

From the large trunks of the dorsal aorta the internal and mesenteric tissues depart, they supply blood to the abdominal muscles, organs of the pelvic cavity, hind limbs, intestines, and stomach.

The circulatory system of birds collects venous blood from the bird's head into the jugular veins, which together with the vessels merge into the right and left hollow veins flowing into the right atrium. From the area of the cloaca, small veins collect blood, then merge together, forming three large.

The circulatory system of insects is an open circle. The blood is not completely enclosed in the muscle capsule attached to the back, the rest of the blood is washed and fills the cavities and gaps between the organs.

Glands of internal secretion secrete hormones that are contained in the hemolymph (blood) of insects. They are responsible for physiological processes. Thanks to blood, an internal pressure is created in the insect's body, which allows spreading the wings, helps the moulting process, unfolding the proboscis, supports the soft bodies of some species.

The circulatory system of insects consists of a heart, united by several successively contracting chambers. They can be up to 8. As a result of contractions, blood moves in the body. Its circulation in the subordinate organs occurs with the help of pulsating membranes - ampoules located in the limbs of the insect.

The circulatory system of arthropods is also an unclosed circle. The internal organs of arthropods are in cavities - sinuses, filled with hemolymph, washing internal organs, then it again returns to the heart and blood vessels. The circulatory system of arthropods has a heart-central organ (there are no ringworms), which is simple. Hemolymph does not participate in the transfer of gases, this function is performed by the trachea.