Heart
Pericardium
• 1. visceral = inseparatable with epicardium
2. parietal = outer layer of sac
3. pericardial cavity
Major vessels
• all covered by visceral pericardium
• pulmonary trunk - exits right ventricle from
anterior surface
• aorta - exits left ventricle just posterior to
pulmonary trunk
• superior vena cava - enters right atrium on right,
posterior to aorta
• inferior vena cava - enters right atrium, inferior to
superior vana cava
• pulmonary veins - (4) upper & lower on right &
left - enter left atrium, posterior side of heart
Surface Structure of Chambers
• Right Ventricle - forms majority of anterior
(sternocostal) surface
• Right Atrium - forms right lateral surface
– auricle - pointed tissue appendage on surface
of both atria
– atrioventricular (coronary) sulcus - groove
separates atrium & ventricle - holds coronary
artery, sinus
Surface Structure of Chambers
• Left Ventricle - forms left side of anterior
surface, most of posterior
– a. anterior, posterior interventricular sulcus separate right, left ventricles - hold coronary
artery and vein
– b. apex - pointed inferior end of heart,
• Left Atrium - most superior
– base of heart
Inner structure of Chambers
• Wall layers - all chambers
– endocardium - inner layer lining chambers continuous with vessel endotheliu
– myocardium - bulk of muscle walls
– epicardium – inseparable with visceral
pericardium
Right atrium
• crista terminalis - ridge of muscle connects
superior and inferior vana cava (= sulcus
terminalis on surface)
• Pectinate muscle - small muscle ridges inside
anterior wall of right atrium
• sinus venarum - smooth surfaced area where
veins enter right atrium entrances of superior
and inferior vana cava, coronary sinus
• Right atriventricular orifice, tricuspid valve
• interatrial septum, fossa ovalis - remnant of
foramen ovale (in fetus) *check if patent
1. Sinus venarum
2. Terminal crest
3. Fossa ovalis
4. Rim or limbus of the fossa ovalis
5. Musculi pectinati
6. Valve of the inferior vena cava
Right ventricle
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anterior wall = sternocostal surface
medial wall = Interventricular septum
inferior wall = diaphragmatic surface
conus arteriosus /infundibulum - superior part of right
ventricle, narrows toward pulmonary trunk
opening to pulmonary trunk, pulmonary valve - behind 3d
left costal cartilage
Right atrioventricular orifice, tricuspid valve - attached at
peripheral edge to anulus fibrosus (ring)
trabeculae carneae - ridges of muscle on inner surface except in conus arteriosus
chordae tendineae - fibrous tissue, attach ends of valve
cusps to papillary muscles
Left atrium
• 4 openings of pulmonary veins
• Left atrioventricular orifice, mitral
(bicuspid) valve
• Pectinate muscle, interatrial septum, fossa
ovalis
Left ventricle
• aortic valve: three cusp, 3rd intercostal space
• ascending aorta - (becomes aortic arch behind
sternal angle)
– R, L coronary arteries - exit ascending aorta just distal
to valve cusps
• Left atrioventricular orifice, bicuspid valve,
anulus fibrosus, chordae tendineae, papillary
muscles
• Trabeculae carneae - except in aortic vestibule (
smooth region, fibrous and leads to ascending
aorta)
Coronary vessels
• Right coronary artery - in coronary sulcus;
travels to the right & inferiorly
– supplies right atrium, right ventricle, posterior part of
interventricular septum, SA and AV node, AV bundle;
also part of left atrium and left ventricle
– Right marginal artery – runs towards the apex of the
heart
– posterior interventricular artery - sits in posterior
interventricular sulcus, supplies both ventricles
(anastomoses with anterior interventricular artery)
– most likely (85%) an atrioventricular (AV) nodal artery
Coronary vessels
• Left coronary artery - curves left in coronary
sulcus, divides quickly
– supplies left atrium, left ventricle, anterior IV septum,
part of right atrium
– anterior interventricular artery - in anterior
interventricular sulcus, to the apex of the heart,
supplies both ventricles and interventricular septum
– circumflex artery. - continues left in coronary sulcus
around to posterior of heart, supplies left atrium, base
of left ventricle
– Left marginal artery, branch of circumflex
Coronary vessels
• The branches of coronary artery are end
branches. They supply regions of cardiac
muscle without overlap of other large
branches. Anastomoses are generally not
large enough for survival.
• Large branch occluded  distal region
ischemic  necrosis  MI
• Risk factor: Coronary atherosclerosis
Coronary vessels
• Angina pectoris:
• Exertion, stress, exercise after meal
• Most common sites for coronary occlusion:
– The anterior interventricular branch of the left
coronary artery
– The right coronary artery
– The circumflex artery of left coronary artery
• Treatment: Bypass operation
Veins
• Great cardiac vein - in anterior interventricular
sulcus - around left side in coronary sulcus,
empties into coronary sinus (along with anterior
interventricular artery)
• Middle cardiac vein - in posterior interventricular
sulcus - also empties into coronary sinus (along
with posterior interventricular artery)
• Small cardiac vein - around right side in
coronary (with marginal branch of the right
coronary artery)
Veins
• coronary sinus - largest coronary vein; in
posterior coronary groove, drains into right
atrium