Embryonic development Flashcards
What do these structures turn into?
Aortic sac
Truncus arteriosus
Bulbus cordis
Primitive ventricle
Primitive atrium
Sinus venosus
Aortic sac- aortic arches
Truncus arteriosus- aortic arches and arteries
Bulbus cordis- right ventricle and outflow tracts
Primitive ventricle- left ventricle
Primitive atrium- parts of right and left atrium
Sinus venosus- superior vena cava and right atrium
What germ layer is responsible for heart?
Mesoderm
What does the endocardial tubes form?
Primitive heart tube
What does the endocardial tubes form?
Primitive heart tube
Importance of heart shunts?
Bypass pulmonary circulation- not needed in utero
What are two shunts? Location?
Foramen Ovale (between atria)
Ductus arteriosus (pulm artery to aorta)
Function umbilical vein/artery
Umbilical vein- carry oxygenated
Umbilical artery- carry deoxygenated
Why can pulmonary circulation be bypassed?
Not required in utero
Foetal circulation
What occurs after first breaths?
First breaths of life -> lungs expand → alveoli in lungs cleared of fluid
What does increase in baby’s bp and reduction pulmonary pressure do?
Reduce need for ductus arteriosus to shunt blood
Closure of shunt
What causes the ductus arteriosus to shut?
Increase in baby’s BP
Reduction pulmonary pressure
What does ductus arteriosus shunt closure lead to?
Increase pressure in left atrium of heart → decrease pressure in right atrium -> foramen ovale closes → newborn circulation
Describe process of newborn circulation?
Increase pressure in left atrium of heart → decrease pressure in right atrium -> foramen ovale closes → newborn circulation
