Heart vol.1

1. SEMINAR
-BY MORESHWAR
PAWAR AND LUBAINA
RAMPURAWALA

2. Heart
Hollow muscular
organ, acts as a
double pump
Conical in shape
Slightly larger than the
clenched fist
Lies free within the
pericardium
Connected superiorly
to the large vessels

3. Heart cont’d
Has 4 chambers: two atria
superiorly and two ventricles
inferiorly, separated from
each other by
atrioventricular and
interventricular grooves
Atria act as the receiving
chambers and the ventricles
as the pumping chambers
Right side of the heart
contains deoxygenated
blood & left side contains
oxygenated blood

4. External Features: Surfaces
The heart has:
Sternocostal (Anterior) surface
Diaphragmatic (Inferior) surface
Base (Posterior surface)
Apex

5. Sternocostal Surface
Formed mainly by
the right atrium and
the right ventricle
separated by vertical
atrioventricular
groove
The anterior
interventricular
groove separates
the right ventricle
from the left
ventricle

6. Diaphragmatic Surface
Formed mainly by
the right and left
ventricles separated
by posterior
interventricular
groove, and a small
part of the right
atrium, into which the
inferior vena cava
opens

7. Base (Posterior Surface)
Formed mainly by the
left atrium, into which
open the 4 pulmonary
veins
Quadrilateral in shape
Lies opposite the apex
Faces posteriorly,
superiorly and toward
the right shoulder

8. Apex
Formed by left ventricle
Directed downward, forward
and to the left
Located posterior to the left 5th
intercostal space, 7-9 cm from
the median plane and just
medial to the left midclavicular
line
Position varies slightly with the
person’s position and the phase
of respiration
Is the point of maximal
pulsation of the heart (the apex
beat can be seen as well as
palpated)

9. Borders of the Heart
The heart has 4 borders:
Right: Formed by the right
atrium
Left: Formed by the left auricle
above and the left ventricle
below
Inferior: Formed mainly by the
right ventricle, and the apex of
the left ventricle
Superior border is where great
vessels enter or leave the heart.
Formed by right and left auricles
and superior part of right & left
ventricle

10. Surface Projection of the Heart

11. Blood Supply of the Heart

12. Arterial Supply
Supplied by right & left
coronary arteries
Coronary arteries arise
from the ascending aorta
immediately above the
aortic valves
Coronary arteries and their
branches are distributed
over the surface of the
heart lying within the
subepicardial connective
tissue

13. Right Coronary Artery
Arises from anterior sinus
of ascending aorta
Runs between the
pulmonary trunk and right
auricle
Runs in the atrioventricular
groove
At the inferior border of the
heart turns posteriorly in
the atrioventricular groove
Anastomoses with the left
coronary artery in the
posterior interventricular
groove

14. Right Coronary Artery: Branches
Right conus artery
Anterior ventricular
branches: 2-3 in number,
largest is the marginal
branch
Posterior ventricular
branches, gives a branch
to atrioventricular node
Posterior interventricular
artery
Atrial branches, & artery of
the sinuatrial node which
also supplies atria

15. Left Coronary Artery
Larger than the right
Supplies major part of the
heart
Arises from the left
posterior aortic sinus
Runs between the
pulmonary trunk and left
auricle
Runs in the
atrioventricular groove
Divides into anterior
interventricular &
circumflex branches

16. Left Coronary Artery: Branches
Anterior interventricular
artery, gives a small
conus artery
Circumflex artery, gives:
Left marginal
Anterior ventricular
Posterior ventricular
Atrial branches

17. Variations in Coronary Arteries
In 35% of individuals, the
sinuatrial artery arises
from left coronary artery
In most of the individuals
(90%), the posterior
interventricular artery is a
branch of right coronary
artery (Right
Dominance). In 10% of
the individuals, it arises
from circumflex branch of
left coronary artery (Left
Dominance)

18. Coronary Artery Anastomoses
Though anastomoses do exist between
the terminal branches of the right and left
coronary arteries, but these are not large
enough to compensate for any sudden
blockage of a large branch.
A sudden blockage of the larger branches
results in myocardial infarction.

19. Venous Drainage cont’d
Anterior cardiac veins
drain directly into the
right atrium
Vena cordis minimi
(Thebesian veins)
open directly into
heart chambers

20. Venous Drainage
Most of the blood drains into the
right atrium through the coronary
sinus, which:
 Lies in the posterior part of the
atrioventricular sulcus
 Is continuation of the great cardiac
vein
 Opens into the right atrium to the
left of the inferior vena cava
Tributaries:
 Small cardiac vein
 Middle cardiac vein
 Posterior vein of the left ventricle
 Oblique vein of the left atrium