Download Anatomy 3: heart, pericardium, coronary vessels

ANATOMY 3: HEART, PERICARDIUM, CORONARY VESSELS
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Location:
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Base at top
Apex at 5th intercostal space @ left, mid-clavicular
line
Inferior border- horizontal apex R sternal border
Left border- apex sternal end of left 2nd
intercostal space
Aortic: posterior sternum; 3rd intercostal space
Pulmonary: Left sternum; 3rd costal jxn
Tricuspid: posterior sternum; 4-5th costal jxn
Bicuspid: left 4th costal jxn
Pericardium
 Tough fibroserous sac
 2 layers: fibrous and serous
Fibrous Pericardium
 Compact collagen fibers
 Attachments:
o sternopericardial ligaments sternum
o Tunica adventitia of vessels (continuous) and pretracheal fascia
o Pericardiophrenic ligament central tendon
Serous Pericardium
 Mesothelium- simple squamous epithelium on layer of subserosal CT
 2 layers: parietal and visceral (epicardium of heart)
o Parietal serous pericardium  pericardial cavity  visceral serous pericardium
 Fluid in pericardial cavity reduces friction
 Cardiac tamponade: pressure develops in the pericardial cavity (from fluid) and causes atria to collapse;
reduces venous return and cardiac output; systemic vv engorge
ANATOMY 3: HEART, PERICARDIUM, CORONARY VESSELS
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Pericardial sinuses
 Where great vessels enter and exit the heart.
 Transverse pericardial sinus
o Reflection along ascending aorta and
pulmonary trunk
o Posterior to aorta and pulmonary
trunk
o Anterior to SVC
o Superior to atria
 Oblique pericardial sinus
o Along pulmonary vv and venae cavae
o Blind recess, inverted J shape
Fibrous Framework
 4 dense collagen rings around valves, septa,
trigones
 Fxn: keep valves open when ventricles/atria
contract; attachement sights for cusps;
electrically insulates atria from ventricles
Pericardium Innervation and blood supply
 Phrenic (C345)
 Sensory ONLY
ANATOMY 3: HEART, PERICARDIUM, CORONARY VESSELS
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 Pericardacophrenic a
3 Layers of Heart
 Epicardium = visceral serous pericardium
 Myocardium = muscle
 Endocardium = endothelium that lines heart and valves
Heart Surface Anatomy
 Apex
o Inferolateral part of LEFT ventricle
o Motionless during cardiac cycle
o Apex beat- mitral valve
 Base
o Posterior heart
o LEFT atrium
 Anterior
o Sternocostal
o RIGHT ventricle
 Inferior
o Diaphragmatic
o LEFT ventricle
 Right pulm
o RIGHT atrium
 Left pulm
o LEFT ventricle
 SO…
o Left ventricle makes up the apex, inferior, and left pulmonary surfaces
o Left atrium makes up base
o Right ventricle makes up anterior surface
o Right atrium makes up right pulmonary surface
Heart Borders
 Right: R atrium b/n SVC and IVC
 Left: oblique, nearly verticle
 Superior: R and L atria in anterior view
 Inferior: nearly horizontal
Great Vessels
 Ascending aorta
 Pulm trunk
 SVC
 IVC
 Pulm vv
Extrinsic Innervation of Heart
ANATOMY 3: HEART, PERICARDIUM, CORONARY VESSELS
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Cardiac Plexus
o Sympathetic, para, and sensory (no somatic fibers)
o ANTERIOR to bifurcation of trachea
o POSTERIOR to ascending aorta near pulmonary trunk bifurcation
o Sympathetics
 Pre- T1-T5 IML
 Post- cervical and upper thoracic chain ganglia
  cardiac plexus SA/AV nodes
 mostly to ventricles, some to atria
 increase chronotropy, dromotropy, and inotropy; increase coronary blood Q
o Parasympathetics
 Pre- DMNX in caudal medulla cardiac plexus
 Post- ganglia in atrial wall
 Terminate- SA/AV nodes
 R. vagus SA
 L vagus AV
 Decrease chronotropy and inotropy; decrease coronary blood Q (constrict)
o Sensory
 Follow sympathetics
 Terminate in T1-4 spinal segments (general sensory info from arm/left side also terminate
at these levels)
 Referred pain from heart dz in L arm, shoulder, and epigastric region
Intrinsic Innervation
 SA, AV nodes
 AV bundle
 Bundle branches
 Extrinsic system MODIFIES rhythm
Coronary AA
 Outer surface heart; DEEP to epicardium
 R/LCA- originate at aorta; first branches
 Arise from aortic sinuses- superior to same named leaflets of aortic semilunar valve
RCA
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SA nodal- R. atrium where SA node is
AV nodalR. marginal- runs along edge
Posterior interventricular a (PDA)dominance
Supplies
 RA
 SA node (60%)
 AV node (80%)
 Most of RV
 Diaphragmatic surface LV
 Posterior 1/3 IVS
determines
ANATOMY 3: HEART, PERICARDIUM, CORONARY VESSELS
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LCA
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Anterior interventricular a (LAD)
o Anastomoses w/ posterior interventricular
a
Circumflex a
o L marginal
o AV nodal branch (20%)
SA nodal branch (40%)
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Supplies
 LA
 Most of LV
 Part RV
 Most IVS including BB
 SA node (40%)
Coronary Dominance
 Defined by which coronary a gives off PIV
a.
 Right: PIV a off of RCA (85-90%)
 Left: PIV a off of LCX a (10-15%)
ANATOMY 3: HEART, PERICARDIUM, CORONARY VESSELS
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Coronary a infarcts
 Common sights = LAD (widow maker), RCA, LCX a
 Cardiac mm can’t regenerate fibrous scar tissue
 Impairs contractility
A.
B.
C.
D.
E.
Apical anterior infarction
Supra-apical anterior infarction
Anterior lateral infarction
Posterior lateral infarction
Posterior infarction
Coronary VV
 Via coronary sinus and its tributaries, anterior and small cardiac vv
 Thebesian vv- small vv that dump directly back into heart
 Coronary sinus:
o Posterior coronary sulcus (AV groove)- b/n LA and LV
o Opens into RA b/n IVC and tricuspid valve
o Valve
Main tributaries
 Great cardiac v
 Small cardiac v
 Middle cardiac v
 Posterior v of LV
 Oblique v of LA