Blood supply to heart –
Rt & Lt coronary artery – both runs in coronary
sulcus
Peculiarities of coronary artery –
These are Functional End Arteries
F –filled in diastole
E –elastic lamina is absent
A – Artery of artery
Functional end arteries - they do not
anastomosis hence they are not end
arteries ;but in case of blockage of
coronary artery the blood received
through anastomosing channel is so less
that they do not meet the required
demand therefore they called end
functional end arteries
Filled in diastole – all the blood vessels in
the body are filled in systole but coronary
arteries filled in diastole
Elastic lamina is absent –coronary artery
are highly muscular vessels and internal
elastic lamina is discontinuous and poorly
developed
Right coronary artery - it arises from anterior
aortic sinus of ascending aorta
Course -
It passes bet Rt auricle & infundibulum of
Rt ventricle
It passes vertically downwards in the AV
groove
The artery runs backwards at the inferior
border of heart & runs posteriorly the
terminal part of Rt coronary artery is
small and anastomosis with the
circumflex branch of Lt coronary artery
Peculiarity – it has a loop at the point
where the posterior interventricular
artery and AV nodal artery arises
Branches –
Rt conus artery
The word conus means infundibulum of
Rt ventricle it is first branch of Rt
coronary artery
It provides nutrition to Rt ventricle
It may arises as a third coronary artery
It anastomosis with Lt conus artery ,a
branch of anterior interventricular branch
of Lt coronary artery to form an
anastomotic necklace around the
infundibulum or the commencement of
the pulmonary trunk
SA nodal artery – it forms vascular ring
around the termination of superior vena
cava it supplies SA node
Rt anterior ventricular branch - they
3 to 4 in number .they pass of rt ventricle
one of the branch is longest and is known
as rt marginal artery it runs along the
inferior border of heart
Posterior interventricular branch - it
passes along the interventricular grove
towards the apex of heart to supply
inferior surface of rt ventricle
AV nodal artery - this supplies AV node
Applied anatomy –
It is commonest artery in causing
myocardial infarction
In 20 to 25 % RT coronary artery also
supplies inferior surface ie diaphragmatic
surface of LT ventricle this surface is
called as RT dominant coronary surface
The cardiac pain due to angina pectoris
or myocardial infraction is usually
referred to the lt pericardium and inner
aspect of arm and forearm
Reason - the heart is supplied by upper
thoracic segment i.e. T1,2,3,4 .spinal
segment. The skin over the pericardium
is supplied by T 2,3,4 segment , the inner
aspect of arm is innervated by T2
segment and the inner aspect of forearm
and hand is supplied by T1 segment
Cardiac pain is there fore referred to
pericardium and inner aspect of arm and
forearm because of same nerve supply
Cardiac pain is usually referred to lt side
bcause cardiac lesion mostly occur in left
half of the heart but if the lesion is in
right half of the heart the pain will be
referred to right side hence it is wrong
notion that cardiac pain is always
referred to the left side .
Coronary disease in old age is less fatal
then in young age because anastomosis
increases and collateral channels
develops with the advancement of age
The slow gradual blocking coronary
artery is less dangerous then sudden
blockage because the arteries taking part
in extra pericardiac anastomosis will
dilate and provide blood supply to the
heart
Left coronary artery
Origin - it is shorter but wider then Rt coronary
and supplies the greater part of myocardium. it
arises from lt posterior aortic sinus of
ascending aorta
Course –
It passes bet Lt auricle and infundibulum
of the Rt ventricle
After the short course it divides into
terminal branches ( circumflex & anterior
interventricular branch )
The circumflex branch is one of the
terminal runs from the LT border of heart
to the back of heart in the AV grove
It gives various branches to the atrium
and ventricle
Applied anatomy –
1. Thrombosis of coronary artery is common
cause of sudden death . this is due to
myocardial infarction and ventricular
fibrillation .
2. Incomplete obstruction due to spasm of
coronary artery causes angina pectoris
referred to LT upper extremity .
Venous drainage –
1. 60% through coronary sinus
2. 40 % thorugh
a. Anterior cardiac vein
b. Thebesian vein
c. RT marginal vein
