Question | Answer |
pulmonary circuit | carries blood to and from the gas exchange surfaces of the lungs |
systemic circuit | transports blood to and from the rest of the body |
arteries | blood is carried away fro the heart by.... or efferent vessels |
veins | returns blood to the heart |
capillaries | small, thin-walled vessels called.... interconnect the smallest arteries and the smallest veins. |
exchange vessels | also called capillaries because their thin walls permit the exchange of nutrients, dissolbed gases, and waste products between the blood and surrounding tissues |
Right atrium | receives blood from the systemic circuit and passes it to the right ventricle |
Right ventricle | pumps blood into the pulmonary circuit |
Left atrium | collects blood from the pulmonary circuit and empties it into the left ventricle |
Left ventricle | ejects blood into the systemic circuit |
coranary sulcus | a deep groove, marks the border between the atria and the ventricles |
marks boundary between the left and right ventricles | anterior interventricular sulcus and the posterior interventriucular sulcus |
epicardium | is the pericardium that covers the outer surface of the heart |
Myocardium | or muscular wall of the heart, forms both atria and ventricles |
endocardium | the inner surface of the heart including those of the heart valves, are covered by the ... |
cardiac muscles | are interconnected by intercalated disc |
Interatrial septum | the ventricles are seperated by much thicker interventricula |
Atriaventricular valves | folds of fibrous tissue, estend into the openings between the atria and ventricles |
automaticity | or autorhythmicity, cardiac muscle tissue contracts on its own in the absence of nueral of hormonal stimulation |
conducting system | the cells responsible for intiating and distrubitng the stimulus to contract are part of the hearts... |
Sinoatrial node(SA node) | is embedded in the posterior wall of the right atrium, near the entrance of the superior vena cava. also known as the cardiac pacemaker or natural pacemaker |
atrioventricular node | sits within the floor of the right atrium near the opening of the coronary sinus |
AV bundle | Also called, bundle of His, is the only electrical connection between the atria and the ventricles |
Purkinje fibers | conduct action potential at a very rapidly, as fast as myelanited axons |
electrocardiogram(ECG or EKG) | electrical events occuring in the heart are powerful enough to be detected by electrodes on the surface of the body. |
P wave | accompanies the depolarization of the atria. |
QRS complex | appears as the ventricles depolarize |
T waves | indicates ventricular repolarization |
P-R intervals | extends from the start of atrial depolarization to the start of the QRS complex rather into R, because of abnormal ECG's the peak can be difficult to determine |
Cardiac arrhythmias | abnormal paters of cardiac electrical activity |
contractile cells | the purkinje fibers distribute the stimulus to the ......... |
cardiac cycle | period between the start of one heartbeat and the beginning of the next is a single......... |
systole | or contraction, the chamber contracts and pushes blood into an adjacent chamber or into an arterial trunk |
diastole | or relaxation, the chamber fills with blood and prepares for the next cardiac cycle |
end-diastolic volume | EDV, the maxium amount of blood that a ventricle will hold |
cardiodynamics | the movement and forces generated during cardiac contractions |
cardiac output | the amount of blood pumped by each ventricle in one minute |
cardiac acceleratory center | controls sympathetic neurons that increase the heart rate |
cardioinhibitory center | controls the parasympathetic neurons that slow the heart rate |
atrial reflex | Bainbridge reflex, involves adjustments in heart rate in response to an increase in the venous return |
afterload | is the amount of tension the contracting ventricle must produce to force open the semilunar valve and eject blood. |
cardiac reserve | the difference between resting and maximal cardiac outputs |
The righ Atrium | recieves blood from the systemic circuit through the two great veins, superior vena cava and inferior vena cava |
cardiac veins | of the heart return blood to the coronary sinus |
coronary sinus | a large thin walled vein that opens into the right atrium inferior to the connection with the superior vena cava |
fossa ovalis | a small shallow depression, persists at the site in the adult heart |
pectinate muscles | the anterior artrial wall and the inner surface of the auricle contain prominent muscular ridges called ........ |
Right atrioventricular vavle | three fibrous flaps or cusps also known as tricuspid |
chordae tendineae | the free edge of each cusp is attached to tendinous connective-tissue fibers called ..... |
papillary muscles | conical muscular projections that arise from the inner surface of the right ventricle |
trabeculae carnea | the internal surface of the ventricle also contains a series of muscular ridges.... |
moderator band | is a muscular ridge that extends horizontally from the inferior protion of the interventricular septum and connects to the anterior papillary muscle |
conus arteriousus | a conical pouch that ends at the pulmonary vavle |
Mitral valve | also known as bicuspid valve |
fibrous skeleton | of the heart consists of four dense bands of tough elastic tissue that encircle the bases of the pulmonary trunk and aorta and the heart valves |