Heart Circulation

placenta , foramen ovale,ductus venosus,ductus arteriosus ,umbilical cord

Placenta

Foramen ovale

Ductus arteriosus

Umbilical cord

Fetal circulation differs from extra uterine circulation because
the fetus derives oxygen and excretes carbon dioxide not from
gas exchange in the lungs but from the exchange in the
placenta.

Right and Left Atrium &
Right and Left Ventricle

Right chambers

Arteries and Veins

tricuspid valve and mitral valve

Veins

Arteries

SVC(dob)-> RA ->TV->RV->PV->PA->LUNGS -> PV->LA->MV->LV->AV-> AORTA->REST OF BODY

IVC->(blood to liver for detoxificaton)->IVC-> RA ->TV->RV->PV->PA->LUNGS ->(OB) PV->LA->MV->LV->AV-> AORTA->REST OF BODY

The PA is carrying the deoxygenated blood, carries blood away
from the heart towards the lungs and the PV is carrying the
oxygenated blood, carry the blood from the lungs towards the
heart.

• Placenta
• Umbilical cord
• Foramen ovale
• Pulmonary arteries

Oxygenated. Because the blood of the fetus is re-oxygenated in
the placenta.
- From the placenta the oxygenated blood will flow towards the
umbilical vein.
- From the umbilical vein the oxygenated blood will pass
through to the Ductus Venosus to bypass the liver because the
liver is still immature but some small amount of blood goes
here to provide nourishment to the liver.
- From the Ductus Venosus the oxygenated blood flow will go
towards the IVC.
- deoxygenated blood from the brain will flow towards SVC
- SVC carry oxygenated blood
- IVC carry deoxygenated blood

1) The opening in SVC
2) IVC
3) Tricuspid valve
4) Foramen ovale

• TV & SVC
• Foramen Ovale & IVC

Because the lungs are not yet functional/ expanding kaya
majority tatawid ng ductus arteriosus an artery to artery
connection. Supplying blood to lower parts of the body
- Once blood is deoxygenated it will be collected by the
umbilical artery to go back to the placenta for re-oxygenation

Placenta → oxygenation blood → umbilical vein →
ductus venosus to bypass the liver → inferior vena cava
→ right atrium → foramen ovale → left atrium → mitral
valve → left ventricle (still oxygenated blood)→
ascending aorta → brain → blood becomes unoxygenated
→ superior vena cava → right atrium → mixed blood →
tricuspid valve → right ventricle → pulmonary artery →
ductus arteriosus → descending aorta (mixed blood) →
lower parts of the body → utilize by body and cell →
unoxygenated blood → umbilical arteries → placenta for
re-oxygenation and detoxification.

- First placenta is out, since this is the first time for the baby to
become separated from the mother. The placenta will no longer
give oxygen to the baby.
- The baby is on his own for the first time. The baby cries. There
will be the first lungs expansion. Then, the expanding lungs
will get blood from the heart. When lungs are expanding blood
from the right-side rushes towards the pulmonary artery going
to the left and right lungs. So, the amount of the blood in the
right side will decrease and the pressure also of the right side is
decreased, the blood goes to the lungs.
- Once the lungs re-oxygenate the blood they will go back to the
pulmonary vein entering the left atrium. The amount of blood
now will increase and the pressure in the left atrium is also
increased.
- Foramen ovale is like a flap it opens and closes the rush of the
oxygenated blood from the lungs towards the pulmonary vein
entering the left atrium it increases the pressure in the left
atrium.
- There is increased pressure in the left atrium. Decreased
pressure in the right atrium and the foramen ovale will slowly
close because of the high pressure on the left side compared to
the low pressure in the right side. Eventually flap will close
- Umbilical vein, umbilical arteries and ductus venosus, since
you clamp and cut the cord, eventually they will constrict,
become ligaments. Ligamentum venosum and arteriousum.
- Ductus arteriosus closed, the increase oxygen concentration in
the blood of the baby will trigger the constriction of the ductus
arteriosus.

12 hours after
delivery

24 hours after delivery.
(maximum waiting time is 48 hours

“m – murmur” upon auscultation.

28 days of life up to the first 2 days of 48
days of life, but on the third day if may murmur pa din it must
be investigated