<Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> In the fetal heart, the foramen ovale (/ fəˈreɪmən oʊ ˈvæli, - mɛn -, - ˈvɑː -, - ˈveɪ - /), also foramen Botalli, ostium secundum of Born or falx septi, allows blood to enter the left atrium from the right atrium . It is one of two fetal cardiac shunts, the other being the ductus arteriosus (which allows blood that still escapes to the right ventricle to bypass the pulmonary circulation). Another similar adaptation in the fetus is the ductus venosus . In most individuals, the foramen ovale closes at birth . It later forms the fossa ovalis . </P> <P> The foramen ovale (from Latin, meaning' oval hole') forms in the late fourth week of gestation, as a small passageway between the septum secundum the ostium secundum . Initially the atria are separated from one another by the septum primum except for a small opening below the septum, the ostium primum . As the septum primum grows, the ostium primum narrows and eventually closes . Before it does so, bloodflow from the inferior vena cava wears down a portion of the septum primum, forming the ostium secundum . Some embryologists postulate that the ostium secundum may be formed through programmed cell death . </P> <P> The ostium secundum provides communication between the atria after the ostium primum closes completely . Subsequently, a second wall of tissue, the septum secundum, grows over the ostium secundum in the right atrium . Blood then only passes from the right to left atrium by way of a small passageway in the septum secundum and then through the ostium secundum . This passageway is called the foramen ovale . </P>

Foramen ovale is located where on the fetal heart