Development of cardiovascular system primitive circulation Primordium of the heart and vessels – in the middle of the 3rd week The heart begins to beat at 22-23 days Sono registration – during the 4th week •Primitive blood circulation. •Heart development (dev. of heart tube, septa and valves) •Aortal arches and their derivatives. •Fetal blood circulation. •Cardiovascular system malformations. DAY 15 – 16 in extraembryonic mesoderm of - yolk sac (vasa omphalomesenterica /vitellina/), - connecting stalk and placenta (vasa umbilicalia) DAY 17 – 18 in mesenchyme of embryo Vessels development: (from week 3) hemangiogenesis - blood islands (insulae sanguinae) Differentiation of mesenchymal cells Þ angiogenic cells: - angioblasts ð endothelium (at the periphery of blood islets) - hemoblasts ð primitive erythrocytes (in the center of blood islets) Blood islet angioblasts hemoblasts primitive endothelium primitive erythrocytes Groups of angiogenic cells in mesenchyma ectoderm mesenchyme endoderm angiogenic cells form a "horseshoe-shaped" space between somatic and splanchnic layer of mesoderm = pericardial cavity. Two endothelial tubes arrise in splanchnic mesoderm. The ventral portion with tubes forms the cardiogenic area ð two heart tubes, while the lateral portions form the dorsal aortae. Krevní oběh, srdce,cévy - 3 Krevní oběh, srdce,cévy - 4 Figure 5 cardev002-2a Cardiogenic region just cranial to the prechordal plate. cardev003-1all Krevní oběh, srdce,cévy - 5 Krevní oběh, srdce,cévy - 5 ð Fusion of heart tubes ð mesocardium dorsale ð diferentiation of heart wall: ● endocardium ● heart jelly ● epimyocardium Vitelline, umbilical and intraembryonic vessels fuse together and form the primitive blood circulation (¹ fetal blood circulation!) ch1-1-a-img4-big.jpg (30258 bytes) Tube7 tube5 Pericardial cavity Cor tubulare simplex Septum transversum Yolk sac Connecting stalk Desc.aorta Asc.aorta Saccus aorticus Truncus arteriosus Sinus venosus right horn degenerate v. cardinalis ant. sin. v. cardinalis com.sin. v. cardinalis post. sin. a. mesenterica sin. aorta dorsalis a. iliaca com.sin. a. umbilicalis sin. from a. iliaca int. v. umbilicalis sin. v. omphalomesenterica sin. Vessels + cor tubulare branchial arteries 1-6 aa.omphalomesentericae Right Leftt Ventral wiew • Histogenesis of heart tube wall • COR TUBULARE SIMPLEX– temporarily suspended on mesocardium dorsale (4). Visceral mesoderm (splanchnopleura, 5) propagates and forms myoepicardial coat ð myocardium (b) + epicardium (a). Below endothelium (d) – layer of cardiac jelly ð subendocardiac connective tissue (c). S2_4_02a a b c d tube5 Heart tube(s) Pericardial cavity (arrows show fixed postioin of cranial and caudal end of the heart tube) conus arteriosus truncus arteriosus cardev015-1a cardev017 cardev018-2a Looping of the heart tube - because growth of the heart tube is faster than growth of the pericardial cavity and both ends of tube are hold by pericardium. tube5 atria1 Bulboventricular loop Ventro- caudally to the right Dorso- cranially ventral view lateral view Cor sigmoideum Truncus arteriosus + saccus aorticus Bulbus cordis Ventriculus Atrium Sinus venosus vv. cardinales communes vv. umbilicales vv. vitellinae Cor tubulare simplex Cor sigmoideum uniloculare Cor quadricameratum Heart tube Septum atrioventriculare A/ Endocardial cushions – from dorsal (3) and ventral (2) wall of atrioventrikular canal. Grow against each other and seperate right and left AV canal (4, 5). B/ Lateral interventricular cushions – bicuspid + tricuspid AV valve. S2_4_07a S2_4_07 Ventriculus Septum interventriculare Grows from apex cordis craniallly to AV septum S2_4_04a 6- membranózní část septa 7- IV septum Atrium Septum atriorum -septum primum s ostium primum (obliteration); ostium secundum -septum secundum with foramen ovale S2_4_06 atria2 S1 – septum primum, O1 – ostium secundum Septum primum Grows from dorsocranial wall – ostium primum (caudally), closes later, and ostium secundum (above) appears by cell apoptosis atria3 S1 – septum primum, SS – septum spurium, O1 – ostium primum, EC – endocard. cushion, Perf – perforation of ostium secundum, SAO – sinoatrial orifice, In septum primum by cell apoptosis foramen secundum will arrise Plné kosočtverce S1 – septum primum, S2 – septum secundum, SS – septum spurium, O1 – foramen secundum, FO – foramen ovale, EC – endocard. cushion, LVV – left venous valve atria4 Septum secundum -semicircular fold, does not reache endocardial cushions; -covers foramen secundum in septum primum and by its free lower margin surrounds foramen ovale atria5 S1 – septum primum (valvula foraminis ovalis), S2 – septum secundum, SS – septum spurium, O1 – foramen secundum, FO – foramen ovale, EC – endokardový polštářek, Perf – perforace, SAO – sinoatriání orificium, LVV – levá venózní chlopeň Blood from v. cava under pressure flows from the right atrium into the left. before and after birth S2_4_06 1. Vena cava superior 2. Venae pulmonales 3. Atrium sin. 4. Atrium dx. 5. Septum primum 6. Septum secundum 7. Primitive left atrium 8. Primitive right atrium 9. Valve of vena cava inferior 10. Valve of sinus coronarius 11. Sinus venosus Sinus venosus vv. cardinales communes vv. umbilicales vv. vitellinae Left veins obliterate and - left part of sinus venosus ð sinus coronarius - right part of sinus venosus ð part of right atrium wall Sinus venosus + atria Truncus arteriosus atrium Sinus venosus: -transvesal part -R + L horns: v. cardinalis comm. v. umbilicalis v. omphalomesenterica On the right side: v. cava sup. from v. cardin. comm. dx.+ v. precardin. dx. v. cava inf. (posthepatic part) from v. omphalomes. dx. On the left side: veins obliterate and give rise to sinus coronarius (pictures - view from dorsal side) Truncus arteriosus + aortic sac separates into: -2 aortic roots with 6 pairs of aortic arches figdev2 Bulbus cordis - cranial – truncus arteriosus - middle – conus arteriosus -caudal – part of ventricle wall File:Gray466.png F1 Bulbus cordis – participate in ventricle wall; in RV - conus arteriosus, in LV – sinus aortae. Heart Bulbus cordis a truncus arteriosus a pair of opposing ridges appear in walls of bulbus cordis and truncus arteriosus. These ridges twist around each other, forming spiral aortico-pulmonary septum. This septum divides bulbus cordis and truncus arteriosus into two channels, the aorta and the truncus pulmonalis. It also participates in the closure of the interventricular foramen S2_4_05 1. Aorta 2. a. pulmonalis sin. 3. Truncus pulmonalis 4. Septum interventriculare (muscular part) 5. right ventricle 6. membranous part of septum interventriculare Septum aortopulmonale cardev033-2 figurelarge11-34 heart\cardev042.gif 368x320 Embryo Heart - Before Birth heart\cardev042a.gif 323x279 Embryo Heart - After Birth File:Embryonic Circulations.jpg Primitive blood circulation Congenital malformations in CVS (the most frequent) •With left – right shunt (without cyanosis) atrial septum defect ventricular septum defect ductus arteriosus apertus (= patens, = persistens) •With right – left shunt (with cyanosis) Fallot tetralogy transposition of great vessels truncus arteriosus (common aorticopulmonal canal) tricuspid valve atresia •Without shunt coarctation of aorta aortic stenosis pulmonary stenosis dextrocardia (+situs inversus) ectopia cordis Atrial Septal Defects a group of common congenital anomalies defects occuring in a number of different forms and more often in females. heartASD patent foramen ovale left-right shunting Ventricular Septal Defect The Ventricular Septal Defect occurs in the interventricular septum, and is more frequent in males that females. heartVSD left-right shunting Patent Ductus Arteriosus occurs commonly in preterm infants, can close spontaneously (by day three in 60% of normal term neonates) the remainder are ligated simply and with little risk. heartPDA left-right shunting Tetralogy of Fallot Named after Etienne-Louis Arthur Fallot (1888) who described it as "la maladie blue" and is a common developmental cardiac defect. The syndrome consists of a number of cardiac defects possibly stemming from abnormal neural crest migration. fallot consists of: 1.ventricular septal defect 2.pulmonary stenosis (valvular or infundibular) 3.results in an overriding aorta 4.right ventricular hypertrophy Transposition of Great Vessels Characterized by aorta arising from right ventricle and pulmonary artery from the left ventricle and often associated with other cardiac abnormalities (e.g. ventricular septal defect). transposition right-left shunting Tricuspid Atresia Blood is shunted through an atrial septal defect to the left atrium and through the ventricular septal defect to the pulmonary artery. The shaded arrows indicate mixing of the blood. Tricuspid_atresia right-left shunting Coarctation of Aorta (preductal or postductal) before or behind ductus arteriosus coarctation Aortic Stenosis Pulmonary Stenosis aortic_stenosis_valvular pulmonary_stenosis_valvular Hypoplastic Left Heart Characterized by hypoplasia (underdevelopment or absence) of the left ventricle obstructive valvular and vascular lesion of the left side of the heart. hypoplastic_left%20_heart Functional_hypoplastic_left_heart hypoplastic left hear functional hypoplastic left heart Double Outlet Right Ventricle De-oxygenated blood enters the aorta from the right ventricle and is returned to the body. double_outlet_right_ventricle Pulmonary Atresia Abnormal blood flow (as indicated by the shaded blue arrow) is from the right atrium and right ventricle through an atrial septal defect to the left side of the heart. Blood can reach the pulmonary arteries only through a patent ductus arteriosus. pulmonary_atresia more images follow fig09 arterial end of heart tube aortic sac dorsal aortae Gray477.svg V. cardinalis communis Veins entering venous end of herat tube: sinus venosus untitled-18a Development of veins At birth, the circulation of the fetal blood through the placenta is stopped and the lungs begin to function. The foramen ovale, ductus arteriosus, ductus venosus and umbilical vessels subsequently obliterate and transform into corresponding ligaments. S2_4_09a S2_4_09 1. Internal carotid artery 2. External carotid artery 3. Common carotid artery 4. Right subclavian artery 5. Arch of aorta 6. Brachiocephalic artery 7. Ductus arteriosus 8. 7th intersegmental artery 9. Pulmonary artery 10. Carotid duct 11. Obliterated right dorsal aorta S2_4_08