anatomi sirkulasi janin-dws a
TRANSCRIPT
FETUS CIRCULATION
Noverika WindasariMercubaktijaya - 2011
Sirkulasi Fetus berbeda dari sirkulasi posnatal :
• Paru
• Ginjal
• GIT
O2 & nutrien dari darah maternal
Saat lahir otomatis terjadi modifikasi ke arah normal
Belum berfungsi
Placenta
Is the “fetal lung”However cellular layers covering the villi are thicker and less permeable than the alveolar membranes in the lungs and exchange is much less efficient
Is also the route by which all nutritive materials enter the fetus and wastes are discharged to the maternal blood
SIRKULASI FETUS
Kebutuhan oksigen Fetus dari placenta
Vena Umbilikalis IVC
vena porta hepar
SVC / IVC RA
RA For. ovale LA LV Aorta asenden:
* 9 % arteri koronaria
* 62 % pembuluh carotis / subclavia
tubuh bagian atas / otak
* 29 % aorta desenden keseluruh tubuh
RV :
* Arteri Pulmonalis
- 80 % duct. Arteriosus aorta desenden tubuh
- 12 % ke paru-paru resistensi pembuluh darah paru meningkat
Perubahan sirkulasi fetus segera setelah lahir
Segera setelah lahir fetus akan menyesuaikan
dengan lingkungan luar
Plasenta paru-paru
Ductus venosus / foramen ovale / ductus
arteriosus tertutup
Umbilikal kord di clamped / kontriksi natural
Changes in Fetal Circulation
& Respiration at Birth At birth, placental circulation is cut off and
peripheral resistance suddenly rises
Pressure in aorta rises until > than in pulmonary artery
Because of placental circulation has been cut off, the infant becomes increasingly asphyxial
Finally, infant gasps several times and the lungs expand
Markedly negative intrapleural pressure (-30 to -50 mmHg) during the gasps contributes to the expansion of the lungs
Changes in Fetal Circulation
……………….& Respiration at Birth
The sucking action of the first breath plus constriction umbilical veins squeezes 100 ml of blood from placenta (the “placental transfusion”)
Once the lungs are expanded, the pulmonary vascular resistance falls to < 20% of utero value and pulmonary blood flow increases markedly
Blood returning from the lungs raises the pressure in the left atrium, closing foramen ovale by pushing the valve that guards it against the interatrial septum
Changes in Fetal Circulation
……………….& Respiration at Birth
Ductus arteriosus constricts within a few hours
after birth, producing functional closure, and
permanent anatomic closure follows in the next
24-48 hours due to extensive intimal thickening
Mechanism producing the initial constriction is
not completely understood, but the increase in
arterial O2 tension plays an important role
Changes in Fetal Circulation
……………….& Respiration at Birth
Relatively high concentrations of vasodilators
(especially prostaglandin) are present in the
ductus arteriosus
Synthesis of the prostaglandin is inhibited by
inhibition of cyclooxygenase at birth
In many premature infants the ductus fails to
close spontaneously, but closure can be
produced by infusion of drugs that inhibit
cyclooxygenase
Perubahan setelah lahir :
A.umbilicalis medial umblical ligament
V.Umbilicalis Lig.Teres (pd hepar)
Duct. venosus VC lig.venosum
Foramen ovale tertutup segera sesudah lahir
penekanan inter atrial septum
Duct arteriosus tertutup Lig.arteriosum
Beberapa kelainan kongenital
1. Tipe sianotik :
- Tetralogy Fallot
- Eisenmenger Syndrome
2. Tipe Non Sianotik :
- ASD
- PDA
- Congnital Aorta Stenosis
- Co Aortasio Aorta