DEVELOPMENT OF HEART AND FETAL CIRCULATION

1. P R E S E N T E D B Y : D R . M A H E S H Y A D A V ( P . G . )
R E F E R E N E C E ( N E L S O N 2 1 T H S O U T H I N D I A A S I A E D I T I O N
A N D I N D E R B I R S I N G H T E X T B O O K O F E M B R Y O L O G Y )
DEVELOPMENT OF HEART
AND FETAL CIRCULATION

2. PRE TEST
 Name the first seen heart ?
 What is series of dilatation and significance ?
 What is foramen ovale ?
 What is spiral septum and its significance?
 Name acyanotic congenital heart diseases ?
 Name cyanotic heart diseses ?
 What is ductus arteriosus and what will happen if it not closed after
birth ?

3.  INTRODUCTION
 CHANGES IN SINU-ATRIAL ORIFICE
 FORMATION OF ATRIA
 FORMATION OF INTER ATRIAL SEPTUM
 DEVELOPMENT OF RIGHT ATRIUM AND LEFT ATRIUM
 DEVELOPMET OF VENTRICLES
 DEVELOPMENT OF INTER VENTRICULAR SEPTUM
 FETAL CIRCULATION
 CHANGES AFTER BIRTH IN CIRCULATION

4. INTRODUCTION
 It is splanchnopleuric mesodermal in origin , from the cardiogenic area .
 First seen in the from of two Endothelial heart tubes – Right and left .
 These endothelial tubes fuse together to form a single tube which shows
series of dilation
1. Bulbus cordis
2. Ventricle
3. Atrium
4. Sinus venosus

8. FORMATION OF A.V. CUSHION

9. FORMATION OF INTER ATRIAL SEPTUM

10. DEVELOPMENT OF RIGHT ATRIUM
 The main part of the right atrium is developed from the half of the
primitive atrium .
 The sinus venosus is absorbed into the right atrium by great enlargement
of the sino atrial orrifice .
 The right half of the atrio ventricular canal is also absorbed into the
right atrium .

12. DEVELOPMENT OF LEFT ATRIUM
1. Left half of the primitive atrial chamber .
2. Left half of the atrio- ventricular canal .
3. Absorbed proximal parts of the pulmonary veins .

14. DEVELOPMENT OF VENTRICLES

16. CONGENITAL ANAMOLY OF THE HEART
1. ACYANOTIC CONEGENITAL HEART DISEASE(LEFT TO
RIGHT SHUNT
o PATENT DUCTUS ARTERIOSUS
o ATRIAL SEPTAL DEFECT
o VENTRICULAR SEPTAL DEFECT
o COARTICATION OF AORTA

17. 2. CYANOTIC CONGENITAL HEART DISEASE
o TETRALOGY OF FALLOT
o TRANSPOSITION OF GREAT ARTERIES
o TRUNCUS ARTERIOSUS
o TRICUSPID ATRESIA

18. FETAL CIRCULATION
 DEFINITION: The fetal circulation is the circulatory system of a
human fetus, often encompassing the entire fetoplacental circulation
which includes the umbilical cord and the blood vessels within
the placenta that carry fetal blood.

19. PATHWAY
Placenta
Umbilical Vein
Umbilical Arteries
Liver
Ductus Venosus
Inferior
Venacava
Right Atrium
Foramen Ovale
Right Lung
Arch of Aoarta
Ductus Arteriosus
Left Atrium
Left Ventricle
Right Ventricle
Portal Vein

20. Umbilical Cord
2umbilical arteries:
return non-oxygenated blood, fecal waste,
CO2 to placenta
1umbilical vein:
brings oxygenated blood and nutrients to the fetus

21. PATHWAY
Oxygenated blood from the placenta
through umbilical vein
fetus
liver
Receives deoxygenated blood from the portal vein
through ductus venosus
Inferior vena cava
Right atrium of heart
through foramen ovale
Left atrium of the heart
Left ventricle of the heart

22. During ventricular systole
Left ventricular blood Right ventricular blood
pumped with < o2 content
Ascending aorta and distributed is discharged
by their branches to the heart, Pulmonary arteries
head,neck,brain,arms. Ductus
arteriosus
Descending aorta
Hypogastric arteries
Umbilical arteries
Placenta

23. During fetal life
350ml per kg per min
Cardiac Output
Following birth
500ml per min
Heart Rate 120-140per min

24. At birth
 Clamping the cord shuts down low-pressure system
 Increased atmospheric pressure(increased systemic vascular
resistance) causes lungs to inflate with oxygen
 Lungs now become a low-pressure system

25. CHANGES IN THE FETAL CIRCULATION AFTER BIRTH
Shunt Functional closure Anatomical
closure
Remnant
Ductus
arteriosus
10 – 96 hrs after birth 2 – 3 wks after
birth
Ligamentum
arteriosum
Formamen
ovale
Within several mins
after birth
One year after
birth
Fossa ovalis
Ductus
venosus
Within several mins
after birth
3 – 7 days after
birth
Ligamentum
venosum

26.  THANK U