Embryology of the heart_ part 1.pdf

10/03/24 Embryology of the heart: part 1 Learning objective: de ne and explain the principle embryological development of the heart. Heart formation: 1. Primitive vessels ( endocardial tubes ) form on both sides of the embryo. 2. Folding of the embryo brings them together, they fuse into a single he...

10/03/24 Embryology of the heart: part 1 Learning objective: de ne and explain the principle embryological development of the heart. Heart formation: 1. Primitive vessels ( endocardial tubes ) form on both sides of the embryo. 2. Folding of the embryo brings them together, they fuse into a single heart tube. 3. Heart tube folds and partitions to create a 4 chambered structure. Heart tube: Heart tube has regions: 1. Sinus venosus ( venous in ow ). 2. Primitive atrium. 3. Primitive ventricle. 4. Bulbus cordis. 5. Truncus arteriosus ( arterial out ow ). There is folding of the heart tube. The bulbus cordis and primitive ventricle grow more on one side and so start to fold over. This results in a groove called the bulboventricular groove. This growth continues and the bulboventricular groove gets deeper and longer. The atrioventricular groove also forms. Partitioning now occurs internally: Now the heart tube needs to be separated internally to form 4 chambers: 1. Formation of the endocardial cushions- these split the atrium from ventricle and will become the AV valves. 2. Partitioning of the atrium- splits single atrium into left and right. 3. Partition of the ventricle- splits single ventricle into left and right. 4. Partitioning of bulbus cordis and truncus arteriosus- into aorta and pulmonary artery. Partitioning of the atria: weeks 5-7 Partitioning of BC and TA: Bulbar and truncal ridges are just endocardial cushions named for their location. They will fuse and form a division known as the aorticopulmonary septum. This separates the aorta from the pulmonary artery. The sinus venosus: Venous in ow to heart which has left and right horns. Left regresses to become coronary sinus, which drains the coronary arteries. Right remains to become part of SVC and part of the right atrium. Go the and there heart HARC is Dre a good development session video 2 on