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Turtle Heart Model

Название Продукция: Turtle Heart Model
модель: ZM043

Подробно о продукте: Turtle Heart Model

Turtle heart
Some reptiles(turtles.lizards.snakes) have three-chambered hearts 1ike amphibians.while others(crocodiles)have fourchambered hearts like birds and mammals.The fourth chamber was formed by the partition of the single ventricle into two—as a result of the gradual formation of a ventricular septum.The hearts of different reptiles have developed to various stages in this phylogenetic process.The model ZoS 54／1—3.a turtle heart (Emys orbkularis)provides an example of a reptile heart with incomplete ventricular septum.
The ventricle of the turtle heart is divided by an incomplete septum into a right(1)and a left(2)section.The venous blood of the systemic circulation flows into the right atrium(3)via a right(5) and 1eft(6)superior vena cava.as well as via an inferior vena cava(7)and the hepatic veins(8).which all unite to form the sinus venosus(9).From the right atrium the venous blood then flows into the right ventricular section f11.The arterial blood of the pulmonary circulation flows through the pulmonary veins(10) into the left atrium(4).then into the left ventricular section(2).Since the two ventricular sections are not completely closed off from each other partial mixing of venous and arterial blood can occur.However.three factors contribute to considerably reduce the mixing of blood: the peculiar inner structure of the ventricle.the arrangement of membranous valves in the efferent vessels.and the specialized contraction mechanism of the cardiac muscle.As a result.the pulmonary artery(13)carries mainly venous blood through the two pulmonary branches(14+15)to the lungs.The left arch of aorta(11).also arising from the right(venous)ventricular section(1).receives mixed blood.while almost pure arterial blood from the 1eft ventricular section(2)flows through the right arch of aorta(12).through the innominate arteries(1 6)and the subclavian arteries(17)to the anterior extremity,and with the pericardium by the apical ligament of the heart(19).