chapter 27 Development of cirCulatory systen
Chapter 27 Development of circulatory system
1 Formation of primitive cardiovascular system
1. Formation of primitive cardiovascular system
1) extra-embryonic blood vessels ---blood island at the middle of 3rd week, wall of the yolk sac mesenchyma proliferate and/ form isolated cell clusters, the peripheral cell become flattened and differentiate into endothelial cell to from endothelial tube central located cells are detached and develop into primitive blood cells(blood stem cell 血岛
1) extra-embryonic blood vessels ---blood island: at the middle of 3 rd week, wall of the yolk sac mesenchyma proliferate and form isolated cell clusters, the peripheral cell become flattened and differentiate into endothelial cell to from endothelial tube; central located cells are detached and develop into primitive blood cells(blood stem cell)
-endothelial tube approach and fuse with each other to form an endothelial tube network endothelial tube network appears in chorionic membrane and body stalk, and connect to vitelline circulation 原始血管 原始血细胞
---endothelial tube approach and fuse with each other to form an endothelial tube network ---endothelial tube network appears in chorionic membrane and body stalk, and connect to vitelline circulation
2)intra-embryonic blood vessels by the 18-20th days, endothelial tube network appears in intraembryonic mesenchyma to form intraembryonic endothelial tube network by the end of 3rd week, intraembryonic and extraembryonic endothelial tube networks connect to each other to form a diffuse endothelial tube network c-endothelial tube networks fuse or disappear to form primitive cardiovascular system
2) intra-embryonic blood vessels ---by the 18-20th days, endothelial tube network appears in intraembryonic mesenchyma to form intraembryonic endothelial tube network ---by the end of 3 rd week, intraembryonic and extraembryonic endothelial tube networks connect to each other to form a diffuse endothelial tube network ---endothelial tube networks fuse or disappear to form primitive cardiovascular system
---primitive cardiovascular system /heart tube paired, by the 4th week, which fuse /arteries dorsal aorta vitelline artery 心管 umbilical artery aortic arch 6 pairs /veins. anterior cardinal vein posterior cardinal vein common cardinal vein主动 vitelline vein 静脉窦 umbilical vein
---primitive cardiovascular system: /heart tube: paired, by the 4 th week, which fuse /arteries: -dorsal aorta: -vitelline artery -umbilical artery -aortic arch: 6 pairs /veins: -anterior cardinal vein -posterior cardinal vein -common cardinal vein -vitelline vein -umbilical vein
2. Development of heart 1)Formation of primitive heart cardiogenic plate: proliferation of splanchnic mesodermal cell to form a pair of longitudinal cell cord. then differentiate into cardiac tube pericardiac coelom: space in mesoderm 围心腔 生心索
2. Development of heart 1) Formation of primitive heart ---cardiogenic plate: proliferation of splanchnic mesodermal cell to form a pair of longitudinal cell cord, then differentiate into cardiac tube ---pericardiac coelom: space in mesoderm
rapid growth of brain vesicles pulls the buccopharyngeal membrane,/the cardiogenic plate and pericardiac coelom forward 围心腔
---rapid growth of brain vesicles pulls the buccopharyngeal membrane, the cardiogenic plate and pericardiac coelom forward
lateral folds of the embryo make the two cardiac tube approach andfuse with each other 背主动脉 心管 e
---lateral folds of the embryo make the two cardiac tube approach and fuse with each other
dorsal mesocardium cardiac tube Invaginate into 心背系膜 pericardiac coelom and connect to it by dorsal mesocardium 心背系膜
---dorsal mesocardium: cardiac tube invaginate into pericardiac coelom and connect to it by dorsal mesocardium