Flashcards in Cardiac Pathophysiology Deck (57)
Describe the location of the heart
-in the mediastium between the 2nd rib and 5th intercostal space.
-2/3rds to the left of the midsternal line and 1/3 to the right.
Describe the layers of the heart and pericardial sac.
-Parietal layer of serous pericardium
-Visceral layer of serous pericardium/Epicardium
What is the purpose of the pericardial sac?
-superficial fibrous pericardium?
-parietal serous pericardium?
-visceral serous pericardium/epicardium
-Pericardial sac- dbl wall, allows for smooth movement. Lubrication, reduces friction.
-Superficial fibrous pericardium: protects, anchors, and prevents overfilling of the heart.
-Parietal serous pericardium and visceral serous pericardium make up the pericardial sac.
-Myocardium: spiral bundles of cardiac muscle cells, the fibrous skeleton of the heart; crisscrossing interlacing layer of CT.
--anchors cardiac muscle fibers
--supports great vessels and valves
--limits spread of action potentials to specific paths.
endocardium: continuous with endothelial lining of blood vessels.
what does a pericardial friction rub sound like?
which layer of the heart accumulates fat as you get older?
What is the purpose of atrial auricles?
-increase atrial volume
what is the coronary sulcus?
-landmark of the heart, "crown" that separates the atria and ventricles.
Atrial walls composed of what type of muscles?
Which vessels enter the right atrium? Left?
-Right: SVC, IFV, and Coronary sinus
-Left: right and left pulmonary veins
which muscle line the ventricles?
which vessels leave the right and left ventricles?
-trabeculae carneae line the ventricular walls
-pulmonary trunk leaves the right ventricle and the aorta leaves the left ventricle.
Equal volumes of blood are pumped to the pulmonary and systemic circuits, true or false.
describe the pressures of the pulmonary circuit and the systemic circuit.
Pulmonary circuit is low pressure.
Systemic circuit is high pressure.
Describe the venous coronary circulation and which parts of the heart they supply.
From coronary sinus, Great cardiac vein wraps around the left ventrical anteriorly and runs down the anterior portion of the left ventricle.
From the coronary sinus, the Middle Cardiac Vein runs posteriorly in the interventricular septum.
From the coronary sinus, the small cardiac vein runs along the right ventricle.
during what period of the cardiac cycle do the coronary arteries receive perfusion?
What is Angina Pectoris?
-thoracic pain caused by a deficiency in blood delivery to the myocardium. Cells are weakened.
-ischemia that occurs over time
-may be exertional that is relieved with rest.
What is an MI?
-prolonged coronary blockage. Cells death, repaired with non-contractive scar tissue
-sudden loss of perfusion
-not relieved with rest
What muscle and tissue anchor the AV valve cusps.
When do you hear heart sounds S1-4
S1 & S2 are heard in everyone
S3- volume overload
S4- some kind of fibrotic change
Fibrous insulator exists between the atrium and ventricles, why?
-give time between atrial and ventricular contraction, keeps everything orderly, allow time for filling of the ventricles.
function of intercalated disks of cardiac muscle?
supports sycronized contraction of cardiac tissue
Contractile tissue of the heart has a long absolute refractory period, why?
-allows proper filling.
What is the Intrinsic cardiac conduction system ?
-network of autorhythmic cells that initiate and distribute impulses to coordinate the depolarization and contraction of heart.
Describe the pathway of electrical conduction of the heart
SA Node...Internodal pathway...AV node...HIS Bundle.....Left and Right Bundle Branches...Purkinje Fibers
*bachmanns bundle runs from the SA node to the left atria.
-have _____ resting
-once threshold has been achieved ____ channels open and produce an action potential.
-Repolarization results from _____ of _____ ______ and opening of voltage-gated K+ channels.
-unstable resting potential.
-inactivation of Ca2+ channels.
Myocardial cells respond to which ion for depolarization?
-influx of Na+ ions into myocardial cells, these are faster.
-mediated by which nerve?
-Vagally mediated by parasympathetics. (keeps SA node in check so its not beating at 100BPM)
- what causes a change between the rate of the SA and AV nodes?
-There are less gap junctions near the AV node, conduction is slower.
What is the only electrical connection between the atria and ventricles?
Atrioventricular Bundle/ HIS Bundle
Purkinje Fibers are located where?
-The His Bundle and both bundle branches are "bundles" of rapidly conducting purkinje fibers.
What is the inherent rate of ventricular foci?