Comparativevertebratecirculatorysystem脊椎动物循环系统比较.docVIP

Comparative vertebrate circulatory system Jing-Hong Ding Biology science of International college, Hunan University of Arts and Science Abstract: The vertebrate circulatory system is a closed-pipe system, It was divided into the cardiovascular system and the lymphatic system. The cardiovascular system including the heart, arteries, veins and capillaries, the blood; lymphatic system including the lymphatic capillary, lymphatic vessels, lymphatic duct, lymph nodes and lymph (the omitted). The circulatory system is the body of material transport and maintain internal environment that the extracellular fluid stability an important system. The circulatory system is an important immune system, and participate in the regulation of body temperature. Key words: Vertebrate The circulatory system The circulation of the blood Portal vein1 . Heart and blood circulation The vertebrate blood in pipe flows continuously according to a certain direction, namely in the back of the body from the front to the back, while in the abdomen is from back to front. But in any animal is a most inferior animal (urochordates) from the blood circulation in the belongs to the open tube, and the blood does not flow along the fixed direction, the regular change of direction, the same vessel to take turns to be the artery and vein, which is unique in the notochord in animal. The heart is a dynamic organ blood circulation, with a muscular wall thick, with a cavity, produce rhythmic contraction, so that the blood circulation flow in blood vessels. 1.1 Blood circulation route Cardiac structure and changes from aquatic to terrestrial vertebrate transition and evolution due to respiratory organs are closely related to gill breathing vertebrates (cyclostomes and fishes) within the heart of all is the blood, the heart will hypoxic blood pressure to the gills, after gas exchange, more oxygenated blood flows through the various parts of the body directly from the gills again, blood back to the heart of Chinese L nights per cycle body 1 weeks after only 1 times in the heart, the blood circulation is a circle, called the single cycle. In a water landing process, respiratory organs from the gills to the lung, the circulatory system is correspondingly changed significantly. Blood back to the heart of the body should be pressure pulmonary gas exchange, become more oxygenated blood back to the heart, and then again, and is extruded to the various parts of the body, blood returns to the heart. The blood through the body in a week two times by heart, blood circulation way for a large circle (OP cycle) and a small (pulmonary circulation), called double loop (amphibian animal has the above). At this point the heart bear the deoxygenated blood and blood pressure to the pulmonary oxygen respectively and each part of the body of the task.1.2 Heart A pericardial heart is located in the cavity, alimentary canal anterior ventral, the coated by pericardial membrane. Fish and pericardial cavity tail two amphibians in the cavity front, terrestrial vertebrate heart back to the ventral side, move to front abdominal cavity.1.2.1 Single cycle animal heart Differentiation of amphioxus head rope animal no heart, rhythmic beat ability of abdominal aorta with, equivalent to the original heart. Gills to breathe the primitive vertebrate heart model is a straight tube consists of 4 successive cavity. The 4 cavity by forward followed: venous sinus, atrial, ventricular and arterial cone. In the course of development that has been twisted to form s shape tube, make vein Dou Hexin real was brought to the ventricular back. Cyclostomata began to have cardiac differentiation, the heart has the basic structure of the vertebrate heart, but venous sinus is very underdeveloped.Cardiac structure of cartilaginous fishes represent leading heart structure of fish typical, by venous sinus, atrial, ventricular and arterial cone four cavity. Conus arteriosus is a thick walled tube, often with valve. The muscle fleshy wall and ventricular as active contraction, is a part of ventricular extending forward. Teleost heart structure and cartilaginous fishes are similar, but different in teleost fishes by artery ball instead of the arterial cone. Artery ball is abdominal aortic base enlargement, wall is composed of smooth muscle, elastic but not active contraction, does not have the valve on the wall.1.2.2 Double circulating animal heart 1.2.3. 1 Incomplete double circulation At the beginning of double cycle period, many blood oxygen and blood can not be completely separated, the double loop called incomplete dual cycle, amphibians and reptiles possess. This is due to the imperfect caused cardiac structure.1) Amphibia Atrial consists of one to two, atrial septum is incomplete (i.e. holes with (without) Isopoda and Caudata) or completely (part of Caudata and Anura free). The left atrium receives more oxygenated blood is returned by the pulmonary vein, right atrium receives blood from vein returned by the body and blood oxygen returned by the cutaneous vein, together into the single ventricle. Amphibian ventricle gapless appeared, but the heart chamber wall is provided with a plurality of muscle trabeculae extending backwards and forwards, to reduce the mixed left, right atrium blood in a certain extent. Arterial and venous sinus developed cone.2) Reptiles Reptiles are still not fully double cycle, but than amphibian progress: intraventricular are not completely separated, multiple blood oxygen and blood further apart. Higher reptiles crocodile has a complete ventricular septal, leaving only a hole (Pan Shikong) is nearly complete double circulation, blood circulation. Arterial cone and venous sinus. 1.2.3.2 Complete double circulationBirds and mammals heart completely separated into left and right atrial and right ventricular, blood and oxygen blood completely separated to form a complete double circulation. Deoxygenated blood from the body back to the heart via right atrial vein into the right ventricle, is pressed into the pulmonary artery arch; more oxygenated blood from the pulmonary vein back to the heart via the left atrium into the left ventricle, is pressed into the arterial arch.2 Arterial system The artery is will be transported to all parts of the body of the vessel by heart Bo out blood (i.e. centrifugal blood vessels), pipe wall thickness and elastic, repeatedly until the branches into arterioles, capillaries.2.1 Basic models of the arterial system 2 1.1 abdominal artery in 1 branches, emanating from the heart, extending forward in the digestive tract. 2.1.2 dorsal aorta of 1, is located in the confluence of digestive tract back, back to 1, branch to the body. 2.1.3Arcuate artery arch connecting abdominal aorta and dorsal artery, embryonic period is generally 6 to. In all but the basic pattern of ridge animal in roughly the same, the part mainly in the arterial arch.2.2 The evolution of each class of vertebrate arterial arch 2.2.1 Fish Due to the gills, fish gills arterial arch in broken into two parts, namely the afferent branchial artery and branchial artery, in the middle of capillary connection, for gas exchange. Cartilaginous fishes retain second to 6 of the aortic arch, teleost retain third to 6 on the aortic arch, the degradation.2.2.2 Amphibian above vertebrate animal Adult because battalion pulmonary respiration, arterial arch not disconnected, and retain only the 3,4,6 of the aortic arch: third of the carotid artery, is distributed in the head and brain; fourth of artery, left and right body artery merged into the dorsal aorta; sixth of pulmonary artery. Amphibian larva belongs gills, and fish like arterial arch; adult because the skin is an important respiratory organs. The sixth arterial arch of pulmonary arteries, branches of the lungs and skin. The birds into the left body arterial arch body degradation, leaving only the right body arterial arch; mammals retain the left aortic arch.3 Venous system Venous collection of systemic blood back to the heart, the heart blood vessel, often with the corresponding artery wall is thin, less elastic. The lumen has valve, to prevent the backflow of blood.3.1 Basic models of the venous system 3.1.1 Fish (including the cartilaginous fish and bony fish) with vertebrate primitive venous system. 3.1.1.1 H main-vein system on the front main vein, collected from the head of the blood; the posterior cardinal vein, collected at the rear of the body wall, gonad and kidney blood; anterior, posterior cardinal vein at the heart of both sides meet, common people to exchange a short total main vein, finally into the venous sinus. 3 1 1.2 Portal system The portal vein is at both ends for capillary lumen without valve, a blood vessel, including hepatic portal vein, blood flow to the liver from the digestive tract collected tail blood into the renal portal vein and pituitary portal system of the kidney.3.2 Venous system in the evolution of the tetrapod 3.2.1 Amphibian The basic model of venous system of amphibian has four classes (mostly tailless amphibian have), namely Y type large vein (or superior vena cava) system and the pulmonary veins. 3.2.1.1 Y venous system instead of H main vein system. The total main vein and anterior cardinal vein with 1 right before the large vein, 1 in posterior cardinal vein was 1 after the big vein instead. 3.2.1.2 Pulmonary vein. Lung appeared the corresponding emergence of pulmonary vein. Pulmonary vein directly into the left atrium, which plays a decisive role for the emergence of atrial septation and blood circulation route. 3.2.2 ReptilesBasically and tailless amphibian similar, but the renal portal degradation. 3.2.3 BirdsThe basic model of venous system has a kind of birds. Re