pulmonary circuit carries oxygen-poor blood from the heart to the lungs and back.
systemic circuit transports oxygen-rich blood from the heart to the rest of the body and back.
Arteries carry blood away from the heart
veins return blood to the heart
Capillaries tiny vessels between the smallest arteries and veins.
Four chambers of the heart the right atrium and ventricle, left atrium and ventricle.
right atrium and ventricle pumps blood into the pulmonary arteries
left atrium and ventricle receives blood from pulmonary veins
atria collects blood returning to heart
ventricles discharge blood into vessels to leave the heart.
pericardial cavity surrounds the heart.
pericardium lines the heart
pericardial fluid small amount of lubricating fluid in heart.
visceral pericardium (epicardium) covers the heart's outer surface
parietal pericardium lines in the inner surface of the pericardial sac.
pericardial sac surrounds the heart and helps prevent overfilling.
mediastinum anterior portion where the heart lies
Three layers of the heart epicardium, myocardium, endocardium
epicardium the visceral pericardium
myocardium the muscular wall of the heart; consists bulk of the heart.
endocardium the epithelium covering the inner surfaces of the heart including the valves.
cardiocytes cardiac muscle cells, smaller than skeletal muscle cells, are almost totally dependent on aerobic respiration.
coronary arteries supplies blood to the heart muscles
intercalated discs cardiocytes are interconnected by ____ ___, which both convey the force of contraction from cell to cell and conduct action potentials.
fibrous skeleton the internal connective tissue of the heart
auricle (atrial appendage) is an expandable extension of the atrium.
coronary sulcus is the deep groove between the atria and the ventricles.
anterior interventricular sulcus depression on anterior surface of the heart - makes the division of left and right ventricles
posterior interventricular sulcus depression on the posterior surface of the heart - marks the division of the left and right ventricles
base the great vessels are connected to the superior end of the heart at the ____.
apex the inferior, pointed tip of the heart
borders: superior, inferior, left, and right the heart sits at an angle to the longitudinal axis of the body and presents the following.
sternocostal surface formed by the anterior surfaces of the right atrium and ventricle
diaphragmatic surface is formed primarily by the posterior, inferior wall of the left ventricle.
interatrial septum the atria are separated by the ____ ____
interventricular septum the ventricles are divided by the ____ ____.
superior & inferior vena cava The right atrium receives blood from the systemic circuit through two great veins
pectinate muscles the atrial walls contain prominent muscular ridges
coronary veins return blood to the coronary sinus which opens into the right atrium.
foramen ovale during embryonic development an opening penetrates the interatrial septum.
fossa ovalis This opening closes after birth, leaving a depression termed ____ ____.
atrioventricular valve (AV) valve which allows blood to flow from the atria to the ventricles
cusps fibrous tissue braced by the tendinous chordae tendinae; AV consists of three
chordae tendinae cord-like tendons that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart.; connected to papillary muscles
papillary muscles muscles that attach to the chordae tindineae
pulmonary trunk Blood leaving the right ventricle enters the ___ ___ after passing through the pulmonary valve.
pulmonary valve valve positioned between the right ventricle and the pulmonary artery
left and right pulmonary arteries Branch from the pulmonary trunk and carry deoxygenated blood to the arteries
left and right pulmonary veins where the left atrium receives oxygenated blood from; it has thicker walls than those of the right atrium.
left atrioventricular valve (mitral or bicuspid valve) Blood leaving the left atrium flows into the left ventricle through _____ _____ ____
aortic valve where blood leaving the left ventricle passes through and into the systemic circuit via the ascending aorta.
ascending aorta Branches off the left ventricle; carries oxygen rich blood to parts of the body above the heart
aortic arch where blood passes through from the ascending aorta and into the descending aorta.
descending aorta the descending part of the aorta that branches into the thoracic and abdominal aortae
aortic & pulmonary valve two semilumar valves; guarding the exits of the left and right ventricles.
regurgitation valves normally permit blood flow in only one direction, preventing (backflow) of blood.
heart sounds the closure of valves and rushing of blood through the heart cause characteristic ___ ___ that can be heard during auscultation.
coronary circulation supplies blood to the muscles of the heart to meet the high oxygen and nutrient demands of cardiac muscle cells.
coronary arteries originate at the base of the ascending aorta, and each gives rise to two branches.
right marginal branch from the RCA, extends toward the apex along the anterior surface of the right ventricle
posterior interventricular branch from RCA, posterior descending artery, runs toward the apex within the posterior interventricular sulcus
left coronary artery one of two arteries from the aorta that nourish the heart (divides into the circumflex and anterior descending branches)
circumflex branch curves to the left within the coronary sulcus, giving rise to one or more diagnal branches as it curves toward the posterior surface of the heart.
anterior interventricular branch. much larger, or left anterior descending branch, runs along the anterior surface within the anterior interventricular sulcus.
anastomoses interconnections between arteries, ensure a constant blood supply.
great and middle cardiac vein collect blood from smaller veins draining the myocardial capillaries; they deliver this venous blood to the coronary sinus.
Coronary sinus a large thin-walled vein that lies in the posterior portion of the coronary sulcus
anterior cardiac veins drain the anterior surface of the right ventricle and empty directly into the right atrium.
cardiac cycle the complete cycle of events in the heart from the beginning of one heart beat to the beginning of the next
atrial and ventricular systole it is contraction and AV valves are closed
atrial and ventriculary diastole relaxation/filling
automaticity or autorthythmicity cardiac muscle tissue contracts on its own, without neural or hormonal stimulation.
nodal cells (nodes) establish the rate of cardiac contraction; depolarize spontaneously and determine the heart rate.
conducting fibers distribute the contractile stimulus to the general myocardium.
Pacemaker cells found in the sinoatrial (SA) node (cardiac pacemaker) normally establish the rate of contraction. The main pacemaker region of the heart is in the wall of right atrium.
sinoatrial node (SA) embedded in the posterior wall of the right atrium, near the entrance of the superior vena cava.
internodal pathways carries action potential to the AV Node
atrioventricular (AV) node cells of the SA node are electrically connected to those of the larger ___ ___ through conducting fibers in the atrial walls.
AV bundle also known as the bundle of His; impulse travels from the AV node to the ___ ___.
right and left bundle branch extends toward the apex and then radiate across the inner surfaces of both ventricles.
purkinje cells convey the impulses to the ventricular myocardium.
Electrocardiogram (ECG or EKG) a recording of electrical activities in the heart.
P wave (atrial depolarization) important landmarks of an ECG include this
QRS complex ventricular depolarization
T wave ventricular repolarization
cardioacceleratory center in the medulla