The document discusses the development of the cardiovascular system from early embryogenesis through the 8th week. It describes how the heart begins as a single tube that undergoes folding and partitioning to form the four-chambered heart. Key events include formation of the trilaminar embryo and heart fields, development of the heart tube, partitioning of the tube into chambers by formation of septa, and shaping of the tube into its adult looping form by the 8th week of development. Abnormalities in these developmental processes can result in congenital heart defects.

1. Development of Cardiovascular
system
Dr.G.Prabavathy
Assistant Professor

2. Objectives
 Formation of the trilaminar embryo
 Origin of cardiogenic cells
 Formation of bilateral heart fields
 Formation of the heart tube
 Folding of the heart tube
 Looping of the heart tube
 Cardiac developmental abnormalities

3.  Day 0 : Fertilisation forming zygote initiating
embryogenesis
 2 cell stage; 4 cell stage; morula
 Week 1 : implantation ( as a blastocyst)
 Week 2 : bilaminar stage (epiblast,hypoblast)
 Week 3 : gastrulation ;primitive streak,notochord
and neural plate begin to form
 Week 4: heart begins to form

4. Cardiovascular system – develops from
mesoderm
Specifically,
splanchnic lateral
plate mesoderm

5. The cardiogenic field is established in the mesoderm just after
gastrulation (~18-19 days) and develops into a fully functional,
multi-chambered heart by the 8th week
angiogenic cell clusters
(angioblasts/hemangioblasts)
(right dorsal aorta)
(right endocardial tube)
blood islands
(developing blood vessels)
cardiogenic field
pericardial cavity
Langman’s fig 12-1

6. Cardiogenic area- cranial end between septum
transversum and prochordal plate

7. • Intraembryonic coelom – pericardial cavity
• Splanchnopleuric mesoderm underneath pericardial
cavity – Primitive heart tube

9. • Heart tube – endocardium of heart
• Splanchnic mesoderm – myocardium and
Epicardium

10. After folding

11. Cardiogenic cords get canalized to form two
endothelial heart tubes

12. PARTS OF THE HEART TUBE

13. Arterial end:
• Truncus Arteriosus –
continuous with aortic
sac having right and left
horns
• Each horn – first
pharyngeal arch artery
arises,
- Continuous with
respective dorsal aorta

14. Venous end:
Sinus venosus
Receives three primitive
veins:
• Vitelline vein – yolk sac
• Umbilical vein –
placenta
• Common cardinal vein –
body wall

15. EMBRYONIC DILATATION ADULT DERIVATIVES
Truncus arteriosus Ascending Aorta and
Pulmonary trunk.
Bulbus cordis.
.
Smooth part of Right
Smooth part of Left ventricle(aortic
vestibule)
Primitive ventricle Trabeculated part of Right
ventricle.and Trabeculated part of
Left ventricle
Primitive Atrium Trabeculated part of Right atrium
Left Trabeculated part of atrium
Sinus venosus Smooth part of Right atrium(sinus
venarum)
coronary sinus
oblique vein of the Left atrium
FATE OF VARIOUS DILATATIONS OF HEART TUBE

16. • Heart tube lies in the
floor of pericardial cavity
After head fold, undergoes
180 rotation, heart tube lie
on the roof of pericardial
cavity
Moore & Persaud fig 13-9
Positioning of Heart tube
in relation to pericardial
cavity

17. Formation of Cardiac wall
• Endocardium–
endothelial heart tube
• Myocardium-
myoepicardial mantle
• Epicardium-
myoepicardial mantle

18. External adult form of heart
Cardiac loop
Dorsal mesocardium

19. Bulboventricular loop

24. DEXTRO CARDIA
• All the chambers of
the heart and
associated blood
vessels are reversed
as a mirror image
• Heart tube bends to
left
• Associated with situs
inversus
Clinical correlation

25. ECTOPIA CORDIS
• rare condition in which is
Heart is exposed on the
surface of the Thorax.
• Due to nonunion of two
pieces of developing
sternum.

26.  Single lumen primitive heart tube is partitioned
into Four chambers by the formation of four
septa:
1.Atrioventricular septum.
2. Interatrial septum.
3. Interventricular septum.
4. Aorticopulmonary septum
Development of various chambers of Heart

27. Formation of Atrio-ventricular septum
• AV septum divides the AV canal into right and left AV canal
• Two thickenings appear – one on dorsal and one on ventral
wall – endocardial cushions or AV cushions