This is a presentation I had made for giving a seminar on Fetal Circulation in the first year of my MBBS course in Maharashtra. Please share it with your juniors and colleagues.Thank You Presentation By Tashif Jilani

1. FETAL CIRCULATION
-
By Tashif (60)
Afaque (73)
Suraj (64)
Sonali (79)
Yash (76)

2. SUBTOPICS:-
• Tashif – Introduction and Process of Fetal
Circulation
• Afaque-Shunts and Pecularities of Fetal
Circulation
• Suraj- Changes in Fetal Circulation after Birth
• Sonali-Congenital Heart Anomalies-1
• Yash-Congenital Heart Anomalies-2

6. What is Fetal Circulation?

8. • Placental Role in Foetal Circulation:
• The circulatory system of the mother is not directly
connected to that of the fetus,
• so the placenta functions as the respiratory center
for the fetus as well as a site of filtration for plasma
nutrients and wastes.

9. •Foetal Lungs:
• Pulmonary vascular resistance is the
resistance offered to blood through
lungs. The resistance is very high in fetus
because of the non-functioning of fetal
lungs. Because of this high pressure, the
blood is diverted from pulmonary artery
into aorta.

12. UMBILICAL ARTERY
• It is a paired artery that is found in the pelvic and
abdominal region of the fetus which extends into
the umblical cord.
• Supplies de-oxygenated blood from the fetus to the
placenta.
• They surround the urinary bladder and then carry
all the de-oxygenated blood out of the fetus.

13. STEPS:-
1. The oxygenated blood,from the placenta (where
gaseous exchange takes place,and not the
lungs),travels through the UMBILICAL VEIN.
2. UMBILICAL VEIN joins with LEFT BRANCH OF
PORTAL VEIN.
3. Divides into 2 parts:-
a)INDIRECT PATH OF IVC :Through substance of liver
b)DIRECT PATH TO IVC:Through DUCTUS VENOSUS
(DV) to IVC.Thus,DV is for BYPASSING hepatic
circulation.

14. • 4)The IVC takes the oxygenated blood to the
right atrium.By the valve of the IVC,this blood
is directed towards the Foramen Ovale.
• Here,it is divided into 2 portions:-
• A)Most of it passes through foramen ovale
into left atrium
• B)The rest of it gets mixed up with the blood
returning to the Right atrium through the
SVC,and passes into the Right ventricle.

15. 5)From the Right Ventricle,the blood passes
forward(mostly deoxygenated) and enters the
pulmonary trunk.
Here,it can take 2 paths:-
1)A small part of it,then reaches back to the left
atrium through pulmonary vein
2)But a large part of it, is made to bypass
(pulmonary bypass) or is short circuited or is given
a short cut, BY THE DUCTUS ARTERIOSES, into the
Aorta.

16. THE LEFT SIDE OF THE HEART
(FINAL FEW PROCESSES TO
COMPLETE THE CIRCULATION)

17. Left Atrium:-
• It has received blood from the from these 2 sources:-
A)The oxygenated blood from the right atrium
B)Small amount of deoxygenated blood from the lungs
• The blood in the left atrium is therefore, fairly rich in
oxygen.
• This blood now passes to the LEFT VENTRICLE and
then to the AORTA.
• Now,the Aorta has received blood from 2 sources:
(a)Left Ventricle (Having Oxygen Rich Blood (75%)
(b)Ductus Arterioses.(Having Moderately
Oxygenated Blood) (50%)

18. • The Aorta, passes the oxygen rich blood (which it
received from left ventricle),through the Carotid
and Subclavian Arteries,to supply the
HEAD,NECK AND THE BRAIN,AND THE UPPER
EXTRIMITIES.
• The rest of the blood gets mixed with the
moderately oxygenated blood coming from the
Ductus Arterioses.
• The parts of the body, that are supplied by
branches of the aorta,arising distal to its junction
with the Ductus Arteriousus,therefore,receive
blood with only moderate oxygen content.

19. STEPS:-
1. The oxygenated blood,from the placenta (where
gaseous exchange takes place,and not the
lungs),travels through the UMBILICAL VEIN.
2. UMBILICAL VEIN joins with LEFT BRANCH OF
PORTAL VEIN.
3. Divides into 2 parts:-
a)INDIRECT PATH OF IVC :Through substance of liver
b)DIRECT PATH TO IVC:Through DUCTUS VENOSUS
(DV) to IVC.Thus,DV is for BYPASSING hepatic
circulation.

22. • 4)The IVC takes the oxygenated blood to the
right atrium.By the valve of the IVC,this blood
is directed towards the Foramen Ovale.
• Here,it is divided into 2 portions:-
• A)Most of it passes through foramen ovale
into left atrium
• B)The rest of it gets mixed up with the blood
returning to the Right atrium through the
SVC,and passes into the Right ventricle.

25. 5)From the Right Ventricle,the blood passes
forward(mostly deoxygenated) and enters the
pulmonary trunk.
Here,it can take 2 paths:-
1)A small part of it,then reaches back to the right
atrium through pulmonary vein
2)But a large part of it, is made to bypass
(pulmonary bypass) or is short circuited or is given
a short cut, BY THE DUCTUS ARTERIOSES, into the
Aorta.

27. THE LEFT SIDE OF THE HEART
(FINAL FEW PROCESSES TO
COMPLETE THE CIRCULATION)

28. Left Atrium:-
• It has received blood from these 2 sources:-
A)The oxygenated blood from the right atrium
B)Small amount of deoxygenated blood from the lungs
• The blood in the left atrium is therefore, fairly rich in
oxygen.
• This blood now passes to the LEFT VENTRICLE and
then to the AORTA.
• Now,the Aorta has received blood from 2 sources:
(a)Left Ventricle (Having Oxygen Rich Blood)
(b)Ductus Arterioses.(Having Moderately
Oxygenated Blood)

31. • The Aorta,passes the oxygen rich blood (which it
received from left ventricle),through the Carotid
and Subclavian Arteries,to supply the
HEAD,NECK AND THE BRAIN,AND THE UPPER
EXTRIMITIES.
• The rest of the blood gets mixed with the
moderately oxygenated blood coming from the
Ductus Arterioses.
• The parts of the body, that are supplied by
branches of the aorta,arising distal to its junction
with the Ductus Arteriousus,therefore,receive
blood with only moderate oxygen content.

34. • 1. Ductus Venosus:
• The Ductus Venosus shunts the portion of left
umblical vein blood flow directly to the
inferior vena cava.
• Allows oxygenated blood from the placenta to
bypass the liver.

35. 2. Ductus Arteriosus:
• Also called Ductus Botalli.
• Connects the pulmonary artery to the proximal
descending aorta.
• It allows most of the blood from the right-
ventricle to bypass the fetus’ fluid-filled non-
functioning lungs.

36. • 3. Foramen Ovale:
• It is an opening in the intra-atrial septum.
• It allows the blood to enter the left atrium from the
right atrium
• It is also called False Septi.

37. • More oxygenated blood for the upper
limb.Hence,the length of the upper limb is
more than lower limbs in fetus.
• Sphincteric action at the junction of left
umbilical vein and ductus venosus regulates
oxygen content of IVC and excessive load on
heart.
PECULARITIES OF FETAL
CIRCULATION:-

38. • Admixture of oxygenated and deoxygenated
blood takes place in the
• Liver
• terminal part of IVC
• both atria and
• distal part of arch of aorta.
• Transseptal blood flow throughout fetal life
through ostium primum and foramen ovale.
Pecularities (Cotd..)

39. Changes in the Circulation
at birth

40. • Soon after birth,several changes takes place in
the fetal blood vessels.
• This leads to establishment of the adult type
of circulation.The changes are as follows:-
CONTRACTION OF THICK MUCLE WALL:-
• The muscle in the wall of the umbilical arteries
contracts immediately after birth,and
occludes their lumen.This prevents loss of fetal
blood into the placenta.
Circulatory Changes at Birth

41. • The lumen of the umbilical vein and the ductus
venosus is also occluded,but this takes a few
minutes after birth,so that all the fetal blood that
is in the placenta has time to drain back to the
fetus.
• The ductus arteriosus is occluded,so that all
blood from the right ventricle now goes to the
lungs,where it is oxygenated.

42. • The pulmonary vessles increases in size,and
consequently,a much larger volume of blood
reaches the left atrium from the lungs.
• As a result,the pressure inside the left atrium is
generally increased.
• Simaltaneously,the pressure in the right atrium is
diminished because blood from the placenta no
longer reaches it.
• The net result of these pressure changes is that
the pressure in the left atrium now exceeds that
in the right atrium causing valve of the foramen
ovale to close.

44. • The vessels that are occluded soon after birth
are,in due course,replaced by fibrous
tissue,and form the ligaments as show in the
following table:-

45. Fetal Structure Adult Remnant
Foramen ovale Fossa ovalis of the heart
Ductus arteriosus Ligamentum arteriosum
Left umbilical vein
Extra-hepatic portion Ligamentum teres hepatis
Intra-hepatic portion (ductus venosus) Ligamentum venosum
Left and right umbilical arteries
Proximal portions Umbilical branches of internal iliac arteries
Distal portions Medial umbilical ligaments

46. CONGENITAL ANOMALIES
• Patent Foramen Ovale
• Patent Ductus Arteriosus
• Ventricular Septal Defect
• Aortic Valve Stenosis
• Pulmonary Valve Stenosis
• Coarctation of Aorta

47. Patent Foramen Ovale
Patent Ductus Arteriosus

49. Ventricular septal defect
Coarctation of Aorta

50. References:-
• https://medlineplus.gov/
• https://my.clevelandclinic.org/health
• https://www.heart.org/en/health-topics
• https://openmd.com/
• https://www.webmd.com/default.htm
• https://www.uptodate.com/home
• https://search.medscape.com/search/?q=atrial%2
0septal%20defect