Development of the Heart and Great Vessels Flashcards
What is the embryological origin of the heart?
The heart develops from the splanchnic mesoderm of the lateral plate mesoderm.
At what week of gestation does the heart begin to develop?
The heart begins to develop in the third week of gestation.
What structure gives rise to the heart tube?
The heart tube arises from the cardiogenic mesoderm.
What are the main regions of the primitive heart tube?
The primitive heart tube has five regions: truncus arteriosus, bulbus cordis, primitive ventricle, primitive atrium, and sinus venosus.
What is the direction of cardiac looping, and why is it important?
The heart tube loops rightward (dextral looping) to establish proper anatomical positioning.
What congenital defect results from abnormal cardiac looping?
Abnormal cardiac looping can result in dextrocardia or situs inversus.
What are the major components of the septum primum and septum secundum?
The septum primum forms the initial partition between the atria, while the septum secundum forms a secondary partition overlapping the foramen ovale.
How does the foramen ovale form in the fetal heart?
The foramen ovale forms as a temporary opening between the atria, allowing right-to-left shunting in fetal circulation.
What structure allows oxygenated blood to bypass the lungs in fetal circulation?
The foramen ovale and ductus arteriosus allow blood to bypass the fetal lungs.
What happens to the foramen ovale after birth?
After birth, the foramen ovale closes due to increased left atrial pressure, forming the fossa ovalis.
What are the key steps in atrial septation?
Atrial septation occurs through the growth of the septum primum and septum secundum, with eventual closure of the foramen ovale.
How does the muscular ventricular septum form?
The muscular ventricular septum forms by upward growth from the base of the ventricles.
What is the role of the endocardial cushions in heart development?
The endocardial cushions contribute to atrioventricular valve and septum formation.
How do the conotruncal ridges contribute to heart formation?
The conotruncal ridges spiral and fuse to form the aorticopulmonary septum.
What is the embryological origin of the aorticopulmonary septum?
The aorticopulmonary septum is derived from neural crest cells.
What are the major derivatives of the truncus arteriosus?
The truncus arteriosus gives rise to the ascending aorta and pulmonary trunk.
How does the spiral formation of the aorticopulmonary septum occur?
The aorticopulmonary septum forms in a spiral pattern, ensuring proper outflow tract separation.
What congenital heart defect results from failure of truncal septation?
Persistent truncus arteriosus results from failure of truncal septation.
What are the derivatives of the bulbus cordis?
The bulbus cordis contributes to the smooth outflow portions of the ventricles.
What congenital defects arise from neural crest cell abnormalities in heart development?
Neural crest defects can cause Tetralogy of Fallot, transposition of the great arteries, and truncus arteriosus.
What are the five key embryonic dilations of the heart tube?
The heart tube dilations are truncus arteriosus, bulbus cordis, primitive ventricle, primitive atrium, and sinus venosus.
Which embryonic structure gives rise to the smooth part of the right atrium?
The sinus venosus forms the smooth part of the right atrium.
What structure forms the trabeculated parts of the atria?
The primitive atrium forms the trabeculated parts of the atria.
What are the main derivatives of the sinus venosus?
The sinus venosus contributes to the right atrium and coronary sinus.
What is the embryological origin of the superior vena cava?
The right common cardinal vein and right anterior cardinal vein form the superior vena cava.
What is the significance of the ductus arteriosus in fetal circulation?
The ductus arteriosus shunts blood from the pulmonary artery to the aorta, bypassing the lungs.
What happens to the ductus arteriosus after birth?
The ductus arteriosus closes to become the ligamentum arteriosum.
What mediates closure of the ductus arteriosus?
Closure of the ductus arteriosus is mediated by a drop in prostaglandin levels and increased oxygenation.
What are the six aortic arches, and what are their derivatives?
The aortic arches develop into structures like the carotid arteries, subclavian arteries, and ductus arteriosus.
Which aortic arch gives rise to the common carotid artery?
The third aortic arch forms the common carotid arteries.
Which embryonic structure forms the right subclavian artery?
The right fourth aortic arch and right dorsal aorta form the right subclavian artery.
What does the left sixth aortic arch develop into?
The left sixth aortic arch forms the ductus arteriosus.
What embryonic structure gives rise to the coronary arteries?
The coronary arteries arise from epicardial mesenchymal cells and aortic root.
What is the embryological origin of the pulmonary veins?
The pulmonary veins develop from the primitive pulmonary venous plexus.
What causes dextrocardia during development?
Dextrocardia occurs due to improper cardiac looping.
What congenital heart defect results from endocardial cushion malformations?
Endocardial cushion defects can cause atrioventricular septal defects.
What is the most common congenital heart defect?
Ventricular septal defects are the most common congenital heart defects.
What are the four components of Tetralogy of Fallot?
Tetralogy of Fallot consists of pulmonary stenosis, right ventricular hypertrophy, overriding aorta, and ventricular septal defect.
How does persistent truncus arteriosus affect circulation?
Persistent truncus arteriosus results in a single outflow tract supplying both systemic and pulmonary circulation.
What developmental abnormality leads to transposition of the great arteries?
Transposition of the great arteries results from failure of aorticopulmonary septum spiraling.
What are the embryological origins of the mitral and tricuspid valves?
The mitral and tricuspid valves develop from the endocardial cushions.
How do semilunar valves develop?
Semilunar valves form from truncoconal swellings and neural crest cells.
What congenital defect results from abnormal semilunar valve development?
Abnormal semilunar valve development can lead to pulmonary or aortic stenosis.
What are the key features of hypoplastic left heart syndrome?
Hypoplastic left heart syndrome is characterized by an underdeveloped left ventricle and aorta.
What is the fate of the umbilical vein after birth?
The umbilical vein becomes the ligamentum teres hepatis.
How does fetal circulation differ from postnatal circulation?
Fetal circulation has three main shunts: ductus venosus, foramen ovale, and ductus arteriosus.
What is the role of prostaglandins in ductus arteriosus patency?
Prostaglandins maintain ductus arteriosus patency before birth.
What is the function of the vitelline veins in development?
The vitelline veins contribute to the portal venous system.
What is the function of the cardinal veins in embryonic circulation?
The cardinal veins develop into the major systemic veins.
What major vessels arise from the aortic sac?
The aortic sac contributes to the formation of the aortic arch and great arteries.
