Session 3 Flashcards
(19 cards)
What happens to the heart in the 8th week of development?
The heart aligns within the pericardium
What structures are formed by the septums in the heart?
2 atria, 2 ventricles, ascending aorta, pulmonary trunk
What is the function of the septum primum during atrial septation?
Grows from the dorsal wall of atrium towards endocardial cushion
What happens to the ostium primum during septation?
Decreases in size
Where does the ostium secundum form?
In the upper portion of septum primum
What does the septum secundum create?
Foramen ovale
What causes the fusion of septum primum with septum secundum at birth?
Increased left atrial pressures
What does the bulbus cordis develop into?
Right ventricle
What leads to the formation of the interventricular septum?
Expansion of both ventricles with diverticulation of the internal wall
What are the components of the conotruncal region?
Conus cordis and truncus arteriosus
What is the role of the ductus venosus in fetal circulation?
Bypasses the liver to join inferior vena cava
How is blood directed to the left atrium in fetal circulation?
Through the foramen ovale
What does the ductus arteriosus connect?
Pulmonary trunk to the descending aortic arch
What structure transports oxygen and nutrients from the placenta to the fetus?
Umbilical vein
What does the ductus arteriosus become after closure?
Ligamentum arteriosum
How long does it take for the ductus venosus to close after birth?
Within 1 week
What structure decreases in size as atrial septation begins?
Ostium primum
What acts as a valve for the foramen ovale?
Septum primum
How does the foramen ovale close after birth?
Due to increased pressures in the left atrium and increased flow through the pulmonary arteries
