Fetal Circulation - Fetal circulation differs from adult circulation in several ways and is designed to ensure a high oxygen blood supply to the brain and myocardium

2. FETAL
CIRCULATION

3. INTRODUCTION
EVERY WOMEN IN HER LIFE
WILL ATTAIN PREGNANCY
,DURING HER GESTATION THE
NUTRIENTS,MINERALS,Etc
ARE PASSED THROUGH
UMBILICAL CORD
IN THE SAME WAY BLOOD AND
OXYGEN TO FETUS WILL PASS
THROUGH UMBILICAL CORD

4. DEFINITION
 ACCORDING TO ANNAMMA JACOB
Fetal circulation differs from adult
circulation in several ways and is
designed to ensure a high oxygen
blood supply to the brain and
myocardium

5. CHARACTERISTICS
*The placenta is the source of
oxygen for the fetus
*Fetal lungs receive less than
1% of blood volume lung do
not exchange gas
*Right atrium of the fetal heart
is the chamber with highest
oxygen concentration

7. STRUCTURES
Fetal circulation contains five
unique structures
1.ONEUMBILICAL VEIN
2.TWO UMBILICAL
ARTERIES
3.DUCTUS VENOSUS
4.FORAMEN OVALE
5.DUCTUS ARTERIOSUS

8. ONE UMBILICAL VEIN
It carries oxygen and nutrients to
the fetus
TWO UMBILICAL ARTERIES
 Carry deoxygenated blood and
waste products from fetus
 This permits most of the highly
oxygenated blood to go directly into
the right atrium

9. In the right atrium most of the well
oxygenated(75%) DUCTUS
VENOSUS
blood directed into the FORAMEN
OVALE by the valve of the inferior
vena cava passes into left atrium

10. PATTERN OF BLOOD
FLOW
 The umbilical vein carrying the
oxygenated blood(80% saturated)
from the placenta enters the fetus at
the umbilicus and runs along the free
margin of the flaciform ligament of the
liver
 The blood carried from the placenta
through umbilical vein enters the
inferior vena cava through ductus
venosus

11.  This permits most of the highly oxygenated
blood to go directly into the right atrium
 In the right atrium most of the well oxygenated
ductus venosus blood directed into the foramen
ovale by the valve of the inferior vena cava
passes into the left atrium
 From the left atrium blood flows into the left
ventricle
 During ventricular systole the left ventricle blood
is pumped into the ascending and arch of aorta
are distributed by their branches to HEART
,HEAD,NECK,BRAIN AND ARMS

12.  This permits most of the highly oxygenated
blood to go directly into the right atrium
 In the right atrium most of the well oxygenated
ductus venosus blood directed into the foramen
ovale by the valve of the inferior vena cava
passes into the left atrium
 From the left atrium blood flows into the left
ventricle
 During ventricular systole the left ventricle blood
is pumped into the ascending and arch of aorta
are distributed by their branches to HEART
,HEAD,NECK,BRAIN AND ARMS

13.  Deoxygenated blood returns from the
head and arms through superior vena
cava enters the right atrium and
passes into the right ventricle
 Blood from right ventricle flows into
the pulmonary artery
 The right ventricle blood with oxygen
content is discharged into pulmonary
trunk

14.  The resistance in the pulmonary arteries
during fetal life is very high the main
portion of the blood passes directly
through the ductus arteriosus into the
desending aorta by passing the lungs
where it mixes with the blood from the
proximal aorta
 70% of cardiac output is carried by the
ductus arteriosus to the desending aorta

15.  The deoxygenated blood leaves
the body by way of two umbilical
arteries to reach the placenta
where it is oxygenated & gets
ready for recirculation
 The mean cardiac output is
comparatively high in fetus & is
estimated to be 350 ml/kg/min

16. CHANGES OF FETAL
CIRCULATION AT BIRTH
 The hemodynamics of the fetal
circulation undergoes profound
changes soon after birth
 1.CESSATION OF PLACENTAL
BLOOD FLOW
 2.INITIATION OF RESPIRATION

17.  CLOSURE OF UMBILICAL
ARTERY
 CLOSURE OF UMBILICAL VEIN
 CLOSURE OF DUCTUS
ARTERIOSUS
 CLOSURE OF FORAMEN
OVALE