Cardiac embryology Flashcards
Where do the blood vessels develop?
Extraembryonic mesoderm (which forms part of the placenta and umbilical cord)
What do the umbilical arteries and veins communicate with?
The developing fetal circulation and placenta
Where does the heart develop?
Cardiogenic mesoderm which develops ~day 18
Where are the atria walls developed from?
Embryological atrium
Smooth part of right atrial wall formed by the right horn of the sinus venosus
Smooth part of left atrial wall formed by its growth into the pulmonary veins
What is the function of right to left shunting in the developing heart?
Bypass the lungs
What is the consequence of an atrial septal defect?
Left to right shunting after birth
Small defects are not cyanotic and can be asymptomatic and close during growth
What Truncus Arteriosus defects can occur?
Failure of bulbar ridge formation (VSD + common arterial outflow) - Cyanotic
Failure of equal division (of aorta + PT) - can lead to right ventricular hypertrophy and cyanosis (esp. with PT stenosis)
What is congenital cyanosis?
Congenital heart defects leading to deoxygenated blood entering arterial circulation (or when insufficient oxygenation takes place)
Which congenital defects can lead to cyanosis?
Transposition of great vessels
Tetralogy of Fallot
Truncus Arteriosus defects
Critical pulmonary stenosis
Which congenital defects are not cyanotic?
Atrial septal defects
Ventricular septal defects
Patent ductus arteriosus
