ANATOMY

1. Development of heart- I
S.B. Rauniyar
22/1/2016

2. HEART
• Greek, Heart = cardia = adj. cardia
• Latin, Heart = cor = adj. coronary.
- It is hollow fibromuscular organ
situated in middle mediastinum.
- covered by pericardium.
• External features:-
Four chamber:- right and left atria,
right and left ventricles.
Groove:- atrioventricular groove(coronary sulcus),
interatrial groove , and
interventricular groove.

3. Contd…..
• Measurement:-
apex to base:- 12 cm
antero-posterior diameter:- 6 cm
transverse diameter:- 9 cm
• Weight :- adult male:- 300 gm
adult female:- 250 gm
• Presenting parts:-
- apex,
- base,
- 4 border ( upper, right, left, inferior)
- 3 surface - anterior or sternocostal,
- inferior or diaphragmatic ,
- left surface.

4. EARLY EMBRYONIC DISC VIEWED
FROM A DORSOLATERALASPECT

5. EARLIEST DEVELOPMENT OF HEART
A mass of mesoderm forming a curve which reaches well beyond
the neural plate and the notochord, called cardiogenic area, near
the head end will give rise to the heart.
Mesenchymal cells in the cardiogenic area form two angioblastic
cords.
The sagittal section below illustrates the three germ layers,
prochordal plate and the cardiogenic area.
Prochordal plate
Cardiogenic area

6. SECTION THROUGH PART OF THE
EMBRYONIC DISC

7. TUBE FORMATION BEGINS
ROSTRALLY
• Angioblastic cords
become canalized to
form two endothelial
heart tubes.
• These endothelial heart
tubes fuse to form a
single endothelial heart
tube.

8. The single endothelial heart tube thus formed shows a
series of dilatations.
These are :-
1 Bulbus cordis
2. Ventricle
3. Atrium
4. Sinus venosus

9. SUBDIVISIONS OF HEART TUBE AND THEIR
FATE

10. CARDIAC LOOPING

11. CARDIAC LOOPING

12. 1-Vitelline Vein 2- UmbilicalVein
3-Common Cardinal Veins
CIRCULATION THROUGH THE PRIMITIVE
HEART

13. Contd….
Bulbus cordis:-
- the cranial most part of the tubular
heart , subsequently divided into 3
parts:-
1. proximal part:-
- later it form trabeculated part of
right ventricle.
2. conus cordis:-
- later it form outflow tract of both
right & left ventricle.
3. Truncus arterious:-
- later it form ascending aorta &
pulmonary trunk.

14. Contd…..
Primitive ventricle:-
- along with the conus cordis will form right &left
ventricle.
- junction of primitive ventricle with bulbus
cordis , is called bulboventricular sulcus.
Primitive atrium:-
- connected with primitive ventricle through
atrioventricular canal.
- Later it will form right &left atria.

15. Contd….
Sinus venous:-
- lies at the venous end of heart tube.
- it has right & left horn.
- each horn receives blood from following 3
veins:-
a. Vitelline vein from yolk sac.
b. Umbilical vein from placenta.
c. Common cardinal vein from body wall.