External features of heart

External features of heart

1. External features of
Heart

2. Pericardium
Pericardium is a
fibroserous sac that
encloses the heart and
roots of the great
vessels.
Relations of
Pericardium:
Anterior:
Body of Sternum
2
nd
to 6
th
costal
cartilages
Posterior:
5
th
to 8
th
thoracic
vertebrae

3. Layers of the Pericardium
1. Fibrous Pericardium
Attached anteriorly to
the sternum by
Sternopericardial
ligaments.
2. Serous Pericardium
Two Layers:
a. Parietal
b. Visceral

4. Serous Pericardium

5. Coverings & Wall of the Heart

6. The lines of reflection between
visceral and parietal
pericardium form two
pericardial sinuses, the
transverse pericardial sinus and
the oblique pericardial sinus.
The transverse pericardial
sinus lies anterior to the
superior vena cava and posterior
to the ascending aorta and
pulmonary trunk.
The oblique pericardial sinus
lies posterior to the heart in the
pericardial sac.
Pericardial Sinuses

7. Pericardial Sinuses

8. 1.Fibrous Pericardium and Parietal layer of serous
Pericardium:
By Phrenic nerves

2. Visceral layer of Serous Pericardium:
By Sympathetic trunk and vagus nerves
Nerve supply of the
Pericardium

9. Location of the Heart

10. Angle of Louis
It is the angle at which the
manubrium and sternum
meet/articulate. It is an anatomical
landmark for finding the second rib,
approx. area of the carina

11. Location of Heart

12. •It lies in the middle
mediastinum.
•The Heart is somewhat
pyramidal in shape, having:
• Apex
• Sterno-costal (anterior
surface)
• Base (posterior surface).
•Diaphragmatic (inferior
surface)
•It consists of 4 chambers, 2
atria (right& left) & 2
ventricles (right& left)
Location of the Heart

13. Heart (Anterior Surface(
Anterior Surface

14. Heart (Posterior and inferior surfaces(
Base
Inferior Surface

15. Borders of the HeartBorders of the Heart
Right border: formed by right atrium
Left border: formed by left auricle and left ventricle
Lower border: formed by right atrium & mainly by right
ventricle + apical part of left ventricle
Upper border: Is formed by the 2 atria

16. Surfaces of the Heart
Sternocostal surface (Anterior surface):
Mainly formed by right atrium and right ventricle.
Diaphragmatic surface (Inferior surface):
Mainly formed by right and left ventricles. Small portion is
formed by right atrium.
Base (Posterior surface):
Mainly formed by left atrium.
Apex: formed by left ventricle

17. Apex of the heart
•Directed downwards,
forwards and to the left.
•It is formed by the left
ventricle.
•lies at the level of left 5
th

intercostal space 3.5 inch
from midline.
Note that the base of the heart is called the base because
the heart is pyramid shaped; the base lies opposite the
apex. The heart does not rest on its base; it rests on its
diaphragmatic (inferior) surface

18. Sterno-costal (anterior)surface
•Divided by coronary (atrio-
ventricular) groove into :
 Atrial part, formed mainly by right
atrium.
Ventricular part , the right 2/3 is
formed by right ventricle, while the
left l1/3 is formed by left ventricle.
The 2 ventricles are separated by
anterior interventricular groove,
which lodges :
Anterior interventricular artery
(branch of left coronary).
Great cardiac vein.
The coronary groove lodges
right coronary artery.
This surface is formed
mainly by the right atrium
and the right ventricle.

19. Diaphragmatic (Inferior)surface
 Formed by the 2-ventricles,
mainly left ventricle (left 2/3).
 Slightly concave as it rests on
diaphragm.
 Directed inferiorly & backward.
Separated from base of heart by
posterior part of coronary sulcus.
The 2-ventricles are separated by
posterior interventricular groove
which lodges:
Posterior interventricular artery
 Middle cardiac vein

20. Base of the Heart (posterior surface)
It is formed by the 2 atria, mainly
left atrium, into which open the 4
pulmonary veins.
It is directed backwards.
Lies opposite middle thoracic
vertebrae (5-7).
 Is separated from the vertebral
column by descending aorta,
esophagus and oblique sinus of
pericardium.
Bounded inferiorly by post. part
of coronary sulcus , which lodges
the coronary sinus.
Left
atrium

21. Heart (Anterior view(
SVC
AAPT
RV LV
IVC
RA
SVC: Superior vena cava
AA: Ascending Aorta
PT: Pulmonary Trunk
RA: Right Auricle
RV: Right ventricle
LV: Left ventricle
IVC: Inferior vena cava

22. Heart (Posterior view(
LA RA
LV
IVC
LA: Left auricle
RA: Right auricle
LV: Left ventricle
IVC: Inferior vena cava

23. Heart (Posterior view(

24. Heart (Anterior interventricular Sulcus or
Groove(
AIS

25. PIS
CS
Heart (Posterior interventricular Sulcus or
Groove)
Coronary or Atrioventricular Sulcus or
Groove