Vasculature, Conducting System, ... Flashcards
supply the heart
Coronary arteries
cardiac veins
coronary arteries are ——sized arteries, but they differ Structurally from the other medium sized arteries in that there
medium
1) Wall is thick
2) The tunica Media of the coronary arteries are thick
3) Internal elastic lamina is clearly seen
4) the sympathetic Stimulation will cause vaso dilation in contrast to other arteries that will constrict
5) the blood inters the coronary arteries during diastole not during systole
Endocardium and subendocardial tissue receive nutrients and oxygen by
diffusion
Blood vessels of the heart are embedded in— deep to epicardium
fat
Blood vessels of the heart are affected by
both sympathetic and parasympathetic nerves
Right and left coronary arteries arise from —— just distal to the aortic valve from the aortic sinuses
ascending aorta
The coronary arteries supply
epicardium and myocardium
The arteries supplying the myocardium (branches of coronary arteries) are——
end arteries,
end arteries, meaning
they do not anastomose, but there is sufficient collateral circulation in the heart
Left coronary artery
1)left coronary artery (the largest one)
2)circumflex branch of LCA
3)left marginal artery (obtuse)
4)anterior interventricular artery (Left anterior
descending, LAD) branch of LCA-
Left coronary artery (LCA)
Arises from left——-passes
between ——-and——-
aortic sinus
pulmonary trunk , left
auricle
In 40% of individuals Left coronary artery (LCA) gives a branch
to
sinuatrial node (SA node; pacemaker
Circumflex branch of LCA-
Follows ———
and enters the————-
coronary sulcus (groove)
post surface of the heart (base)
Lt marginal artery (obtuse)
Follows——- and supplies——-
left margin
left ventricle
Anterior interventricular artery (Left anterior
descending, LAD)
It descends in————
Reaches apex and turns around and enters the—-
anterior interventricular groove
diaphragmatic surface
LAD It commonly
anastomoses with
post
interventricular branch
of Rt coronary artery
Great cardiac vein- Non-coronary aortic sinus;
Accompanies LCA
and joins on the—— with the———
posterior surface
coronary sinus (vein)
When it comes to the interventricular groove on the anterior aspect the left coronary artery divides into two branches
T
Base of the heart
Circumflex branch of LCA-
Circumflex branch of LCA- • Reaches post part of coronary sulcus • Most commonly it does not reach the——— • Supplies post aspect of the heart
middle
part of the
diapragmatic surface
Crux of the heart
is the + point
formed by the 2
ventricles and 2
atria
The circumflex branch reaches the crux and
anastomoses with the right coronary artery
Right coronary artery
1) Right coronary artery (RCA)-
2) Right marginal branch of RCA
3) Atrial branch of RCA
4) Atrial and ventricular branches of RCA (AV) nodal
5) SA nodal branch from RCA- In 60% of individuals
6) Post interventricular artery (post
descending artery PAD)
Right coronary artery (RCA)-
Arises from
right aortic
sinus
RCA Runs downwards in———Reaches——- and
enters the
———
coronary sulcus
inf border
diaphragmatic surface
RCA and the circumflex will form anastomoses (the RCA will run posteriorly to the crux where it meets the circumflex branch)
T
Atrial branch of RCA
disappear immediately deep to the ——-e and reappears———
right auricle
anterior to the superior vena cava
Atrial and ventricular branches of RCA Supply
atria and ventricle
Right marginal branch of RCA Runs towards
the apex, but does not reach
Coronary arterial dominance is defined by the vessel which gives rise to the posterior descending artery (PAD). 18% of the cases both arteries give PAD so there will be 2 PADs this is called co- dominance
T
Areas of the heart supplied by the coronary arteries
LCA Supplies :
-Left atrium and left ventricle
-Sometimes SA node (40%) AV node -Atrioventricular bundle (conducting
system
-small anterior part of rt ventricle
-Ant 2/3 of interventricular septum
RCA Supplies :
- Most of right atrium
- Pulmonary trunk
- SA node (60%) and AV node
- small post part of lt ventricle
- Right ventricle and apex of heart
- Post 1/3 of interventricular septum
most common occlusion points in the coronary arteries
1) anterior interventricular branch
2) right coronary artery
3) circumflex branch
Variations in distribution of coronary arteries
Slides
Venous drainage of the heart
- Great cardiac vein accompanies the ant interventricular artery
- Middle cardiac vein accompanies post interventricular artery
- All veins, except ant cardiac veins, open into coronary sinus
- Coronary sinus is the largest vein of the heart and opens into the right atrium
- Ant cardiac veins open into right atrium
The conducting system, which coordinates the cardiac cycle, consists of—— cells and highly specialized
cardiac muscle
conducting fibers
SA node-located
deep to epicardium
SA node is a • Specialized cardiac muscle and fibroelastic tissue-pacemaker of the heart • Initiates and regulates impulse for contraction 70 times/min • Influenced by sympathetic and parasympathetic fibers
T
AV node is smaller, but like SA node tissue-located
near the opening of SA node coronary sinus (triangle of Koch) in post- inf part of inter-atrial septum
AV bundle (of His)-transmits signals to
ventricles (only connection between atria and ventricles)
SA and AV nodes are
usually supplied by
RCA
The AV bundle traverses
through the center of the
——, thus supplied by
IVS
LCA (through LAD)
————containing Purkinje fibers
Moderator band (septomarginal trabecula)
Purkinje fibers stimulate the
ventricles, IV septum and papillary muscles
