Heart Anatomy; part-02
DR MD FAHAD IBNA MAHAFUZ
✅ Crux of the heart:
Meeting point of –
Interatrial
Posterior interventricular and
Posterior part of AV groove.
Termination of RCA:
10% 10% 60% 20%
Ends at intervals Traverses entire
Ends at inf border b2in inf border & post part of AV
crux. groove.
Normal Anastomosis Functional End Arteries True End Arteries
This occurs when an While a pre-capillary These arteries operate
anastomosis is sufficient to anastomosis exists, it's not independently with no pre-
maintain collateral circulation sufficient to maintain capillary anastomosis between
even under physiological or collateral circulation during adjacent branches . Therefore,
pathological demand. If one pathological demand, such as if one is blocked, there's no
artery is blocked, blood can an artery blockage. This collateral circulation, resulting
still reach the affected area means a blockage can lead to in a complete lack of blood
through the anastomosis from damage and loss of function supply and damage to the
another artery. in the affected area. served area .
Ex: Coronary artery. Ex: Central artery of retina.
Blood supply:
A. Artery supply &
B. Venous drainage.
A. Artery supply: By right & left coronary arteries.
✅ Course:
: Arises from the (above the right cusp of the aortic valve).
Right coronary artery Left coronary artery
Origin right or anterior aortic Origin Left or left posterior
sinus. aortic sinus,
Forwards & to the between the right Forwards & to the between the left
right auricle and root of the left auricle and root of the
pulmonary trunk. pulmonary trunk.
Downwards Downwards
winds round the inferior border to winds round the left border to reach
reach the the diaphragmatic
diaphragmatic surface surface of the heart.
of the heart.
backwards & to the in the right posterior backwards & to the in the left posterior
left AV groove to reach right AV groove to reach
the crux. the crux. Terminates
by anastomosing with
RCA.
� Area of distribution:
RCA LCA
Atrium Rt Lt
Rt ventricle Greater part except near ant IVG Small area near ant IVG
Lt ventricle Small area near post IVG Greater part except near post IVG
Interventricular Post. Part Ant. Part
septum
Junctional Whole except Lt bundle branch SA node Lt bundle branch SA node (40%).
tissue (40%).
� Major Branches:
RCA LCA
rd
1. Rt conus artery/ 3 coronary artery 1. Ant interventricular branch
(Sometimes arises directly from the right aortic
sinus) * Ant ventricular artery
2. Atrial branches - Lt diagonal
- SA nodal artery - Lt conus
3. Ant ventricular branches - Septal
- Marginal artery 2. Circumflex artery
4. Post. Ventricular branches - Lt marginal
5. Post interventricular artery/ Post - Post ventricular branches
descending artery (PDA)
- Atrial branches
- large septal artery
- SA nodal artery (10%)
- AV nodal artery
- AV nodal (10%)
� Coronary Dominance
Determined by the origin of the posterior interventricular artery:
o Right-dominant: PDA arises from RCA (~65–80%) / 90%
o Left-dominant: PDA from left circumflex (~20%) / 10%
o Co-dominant: Both contribute.
*** Lt dominant people are likely to be affected by coronary diseases, because the entire lt
ventricle & the ventricular septum are under the nutritional control of LCA, and
obstruction of the latter may produce output failure of systemic circulation.
Venous drainage:
60% 40%
Coronary sinus Anterior cardiac vein and
Venae cordis minimi / smallest cardiac vein.
Sinus = dilated vein
Vein Sinus
Not dilated Dilated
Has smooth muscle No smooth muscle in wall
Has valve No valve
Coronary Sinus and its tributaries:
3 cm
Largest
Located: Post coronary sulcus
End: Post wall of Rt atrium
Valve: Thebasian
Tributaries:
Great cardiac vein
Middle cardiac vein
Small cardiac vein
Inferior vein of left ventricle
Oblique vein of left atrium
Right marginal vein
Left marginal vein
INTERIOR
Right Atrium Left Atrium
Posterior smooth part/ Sinus Anterior rough part/ Interatrial septum
venarum Atrium proper
1. Opening of SVC (no valve) 1. Crista terminalis 1. Fossa ovalis 1. Most of the wall is
2. Opening of IVC 2. Musculi pectinati 2. Limbus fossa smooth.
(Eustachean Valve) (causes of roughness) ovalis (annulus 2. Musculi pectinati
3. Opening of coronary sinus 3. Opening of anterior ovalis) found within left
(Thebesian valve) cardiac vein 3. Triangle of Koch auricle.
4. Foramina venarum 3. Posterior wall
minimarum/opening of venae receives opening of
cordis minimi four pulmonary veins.
5. Intervenous tubercle 4. Anteriorly
communicates with
left AV opening.
INTERIOR
Right ventricle: 2 parts
Rough inflowing part/ inflow tract/ventricle proper Smooth These two parts
1. Trabeculi carneae [causes of roughness-(roughness slow the outflowing are separated by
inflow)]: muscular ridges. part/ outflow supraventricular
3 types tract/ conus crest/
Ridges Bridges Pillars arteriosus/ infundibulo-
infundibulu ventricular
m crest.
Attached to the ventricle Connects the ventricular Attached to the
throughout their length. walls but free in the ventricular wall
middle. from one end
only. Other end
connected to
cusps of
tricuspid valve
by chorda
tendineae.
Supraventricular crest. Septomarginal Papillary
trabeculum/ moderator muscles.
band which extends 3 in RV.
from ventricular septum 1. Anterior
to ant papillary muscle. (largest)
It conveys rt branch of 2. Posterior
AV bundle. 3. Septal
Interior of lt ventricle: 2 parts
Rough inflowing parts Smooth outflowing parts/ aortic vestibule
Trabeculae carneae (causes of roughness)
RV LV
Wall thin 3 times thicker----why?
Lumen semilunar Circular-----why?
3 pillars 2 pillars
In RV, the blood flow tract makes roughly an obtuse angular band, bcoz outflow orifice situated above and left to
the inflow tract.
Intra ventricular septum:
-obliquely placed
- parts: 2
1. upper: thin & membranous
2. Lower: thick & muscular
Arterial supply of IVS:
1. Ant IVA: Ant 2/3rd
2. Post IVA: Post 1/3rd
Valve: Maintain unidirectional blood flow & prevent opposite direction of blood flow.
AV Semilunar
Rt/tricuspid Lt/bicuspid Pulmonary Aortic
3 cusps (fold of 2 cusps 3 cusps 3 cusps
endocardium) 1. Ant
1. Ant 2. Post
2. Post
3. Septal
When closed 1st Heart sound produced When closed 2nd Heart sound produced
FIBROUS SKELETON OF HEART
