Cardio embryology Flashcards
What are the first signs of cardiovascular development in the embryo
Formation of blood Islands and myoblasts
Blood cell development first begins where
endothelial lined tubes then moves to the liver then to the bone marrow
First form of the heart?
Endothelial tube
What is the sinus venosus
Thats where blood from the placenta comes into the fetal heart, then goes to the unpartitioned atrium, unpartitioned ventricle, bulbus cortis
Truncus arteriosus develops into
Aorta and pulmonary trunk
Bulbus cortis turns into
The parts of the left and right ventricle inferior to the aorta and pulmonary trunk
primordial ventricle turns into
rt and left ventricle
Sinus venosus
left horn turns into coronary sinus, right horn into rt atrium
Does the atrium ever get fully partitioned during the fetal period?
No, because you want the blood flow to go from right to left and get into the systemic circulation without going through the undeveloped lungs
Ostium primum
opening between left and right atria
Describe developemnt of the atrial septa
As the septum primum grows down towards teh endocardial cushion, holes develop in its superior portion (ostium secundum) that allow blood flow to continue to flow from right to left atria even as the ostium primum closes
Foramen ovale
A hole in the septum secundum (a crescent shape septum that drops next to the septum primum) that allows blood to pass through the atrial septum
Changes in pressure after birth
Before birth, the right atrium is under very high pressure b/c of the blood flow coming in from the placenta. This pressure allows the blood to go through the foramen ovale to the right side. After birth, the placental flow stops. blood goes to lungs and then to left atrium so pressure reverses and is high on the left
What about the little bit of blood that makes its way to the right ventricle and tries to move into the lungs via the pulmonary trunk during prenatal life?
It is shunted through the ductus arteriosus which attaches the pulmonary trunk to the aorta.
Ventricular septum has a muscular portion and a membranous protion
true…membranous part comes from endocardial cushion…muscular part comes from a ridge in the myocardium
Left to right atrial shunt is caused by?
Excessive resorption of the septum primum or absence or septum secundum or potentially absence of both
Left to right atrial shunt leads to
Pulmonary hypertension. You get right atrial and ventricular overload that gets pumped to the lungs. Too much blood in the lungs
Ventricular septal defect almost always found where?
Membranous part of the septum
Left to right ventricular shunting can cause?
Cyanosis
Eisenmanger complex
When congenital defects lead to pulmonary hypertension and enlarged right heart usually due to a left to right shunt
Atrial defects lead to eilenmanger complex more slowly than ventricular
true
Septum that divides the aorta and pulmonary trunk comes from
neural crest cells…its a spiral septum, know that
Three conditions that cause cyanosis
Tetralogy of Fallot, transposition of the great vessesls, persistent truncus arteriosus
What is tetralogy of fallot
occurs when the aorticopulmonary septum shifts to the right and fails to alight properly. Results in pulmonary stenosis, overriding aorta, interventricular septal defect, right ventricular hypertrophy. Causes right to left shunting. Basically its a small pulmonary artery and a big aorta
