Zusammenfassung der Ressource
Fetal Circulation
- Foramen Ovale
- Normally closes at birth and forms the fossa ovalis (depression in RA)
- Closes due to decreased pulmonary pressures and
when the LA pressure exceed the RA pressure
- In about 30% of adults they may still have a
small PFO that hasn't closed completely at birth,
this can increase risk of cerebrovascular events
- Fetal cardiac shunt which allows blood to
enter the LA from the RA
- Allows blood to bypass the nonfunctional fetal lungs while
the fetus obtains its oxygen from the placenta.
- Develops in the late 4th of gestation
- Ductus Arterosis
- Connects the PA to the proximal
descending aorta
- Allows most of the blood from the
RV to bypass the fetus's fluid filled
non-functioning lungs
- Upon closure at birth becomes
ligamentum artiosum
- Non functional and formed within three
weeks of birth
- Can play a role in major trauma as it fixes the
aorta in place and during rapid recoil can result in a ruptured aorta
- Patent ductus arteriosis
- When the ductus arteriosis fails to close