| Question |
Answer |
| Where is the heart located in the chest? |
mediastinum; the medial cavity of the thorax |
| What is the double-walled sac called that encloses the heart? |
Pericardium |
| What is the loosely fitting connective tissue part of the pericardium called? |
fibrous pericardium |
| What is the function of the fibrous pericardium? |
protects the heart; anchors it to surrounding structures and prevents overfilling of the heart with blood |
| What is the thin, slippery, 2-layer serous membrane called that is deep to the fibrous pericardium? |
serous pericardium |
| What is pericarditis? |
inflammation of the pericardium |
| What are the 3 layers comprising the heart wall? |
1. epicardium (upper layer aka visceral pericardium) 2. myocardium (middle layer-cardiac muscle) 3. endocardium (inner layer-endothelium) |
| What is the myocardium comprised of? |
cardiac muscle |
| What are the heart's connective tissue fibers called that form a dense network?
What is its function? |
fibrous skeleton of the heart
reinforces the the myocardium internally and anchors cardiac muscle fibers |
| What is the endocardium comprised of? |
endothelium (squamous epithelium) |
| What are the 4 chambers of the heart? |
2 superior atria and 2 inferior ventricles |
| What is the internal partition that divides the heart longitudinally called? |
The interatrial septum (separates the atria)and the interventricular septum (separates the ventricles) |
| What encircles the junction of the atria and ventricles like a crown? |
coronary sulcus |
| What cradles the anterior interventricular artery, marks the anterior position of the septum separating the right and left ventricles? |
anterior interventricular sulcus |
| What is the counterpart for the anterior interventricular sulcus? |
posterior interventricular sulcus |
| What are auricles? |
small, wrinkled, protruding appendages which increase the atrial volume somewha |
| what are pectinate muscles? |
a smooth-walled posterior part and an anterior portion inside the right atrium, ridged by bundles of muscle tissue |
| What returns oxygen-poor blood from body regions superior to the diaphragm? |
superior vena cava |
| What returns oxygen-poor blood from body areas below the diaphragm? |
inferior vena cava |
| What collects blood draining from the myocardium? |
coronary sinus |
| How many pulmonary veins enter the left atrium and deliver oxygen-rich blood from the lungs to the left atrium? |
4 |
| What do the pulmonary veins do? |
transport blood from the lungs back to the heart |
| What are the actual pumps of the heart? |
Ventricles |
| What does the right ventricle do? |
pumps blood into the pulmonary trunk |
| Where does the left ventricle pump blood into? |
aorta; the largest artery in the body |
| What are the blood vessels called that carry blood to and from the lungs? |
pulmonary circuit, which serves gas exchange |
| What are the blood vessels called that carry the functional blood supply to and from all body tissues called? |
systemic circuit |
| What is the right side of the heart called? |
pulmonary circuit pump |
| Which veins carry oxygen rich blood and which circuit are they found? |
pulmonary; pulmonary circuit |
| Which side of the heart is the systemic circuit pump? |
Left side |
| Which circuit is a short, low-pressure circulation? |
pulmonary |
| Which circuit is a long pathway and encounters about 5 time more resistance to blood flow? |
systemic circuit |
| What is the shortest circulation and supplier of functional blood supply of the heart called? |
coronary circulation |
| What 2 branches does the right coronary artery divide into? |
marginal artery, which serves the myocardium of the lateral right side of the heart
posterior interventricular artery, which runs to the heart apex and supplies the posterior ventricular walls |
| Complete blockage of what leads to tissue death and heart attack? |
coronary artery |
| What veins collect venous blood after passing thru the capillary beds of the myocardium? |
cardiac veins |
| The cardiac veins join together to form an enlarged vessel called what and empties blood where? |
coronary sinus, which empties the blood into the right atrium |
| What are the 3 large tributaries called in the sinus? |
great cardiac vein; middle cardiac vein; small cardiac vein |
| What is thoracic pain caused by a fleeting deficiency in blood delivery to the myocardium, causing blockage of the coronary arterial circulation? |
angina pectoris |
| What causes angina pectoris? |
stress-induced spasms of coronary arteries; increased physical demands on the heart |
| What is prolonged coronary blockage called? |
myocardial infarction, aka heart attack |
| Where is the most serious damage done in myocardial infarction? |
left ventricle |
| What do the 2 AV valves prevent? |
backflow into the atria when the ventricles are contracting |
| What is the right AV valve called? |
tricuspid valve |
| What is the left AV valve called? |
mitral valve, (sometimes called the bicuspid valve) |
| What is attached to each AV valve flap? |
tiny white collagen cords called chordae tendineae aka heart strings |
| What is the function of the chordae tendineae? |
to anchor the cusps of the AV valves to the papillary muscles protruding from ventricular walls |
| Which 2 valves guard the bases of the large arteries issuing from the ventricles and prevent backflow into the associated ventricles? |
aortic and pulmonary (semilunar, SL) valves |
| What is it called when the myocardium behaves as a single coordinated unit? |
functional syncytium |
| What % of cardiac cells are mitochondria? |
25-35% |
| What is it called when a region of heart muscle is deprived of blood? |
ischemic |
| What can a large area of ischemic lead to? |
heart attack |
| What consists of noncontractile cardiac cells specialized to initiate and distribute impulses thru out the heart so that it depolarizes and contracts in an orderly, sequential manner? |
cardiac conduction system |
| What are pacemaker potentials or prepotentials? |
spontaneously changing membrane potentials |
| What produces the rising phase of the action potential and reverses the membrane potential in autorhythmic cells? |
Influx of CA2+ |
| What is an ectopic focus? |
An abnormal pacemaker |
| What pace is set by the AV node (junctional rhythm) |
40-60 bpm |
| What part of the nervous system increases the heart rate and force of the beat? |
sympathetic |
| What part of the nervous system decreases the heart rate? |
parasympathetic |
| What are the 3 distinguishable waves or deflections of a typical ECG? |
P wave-atrial depolarization - spread of impulse from SA node over atria;
QRS complex (ventricular depolarization - spread of impulse through ventricles;
T wave-ventricular repolarization |
| What does the term systole refer to? |
contraction period |
| What does the term diastole refer to? |
relaxation period |
| What are all events associated with the blood flow thru the heart during one complete heartbeat referred to as? |
cardiac cycle |
| What is the amount of blood pumped out by each ventricle in 1 minutes and is the product of heart rate and stroke volume referred to as? |
cardiac output |
| What is the volume of blood pumped out by one ventricle with each beat called? |
stroke volume |
| What is the difference between resting and maximal CO (cardiac output) referred to as? |
cardiac reserve |
| What are the 3 most important factors that affect SV (stroke volume) |
preload; contractility; and afterload |
| What is the amount of blood returning to the heart and distending its ventricles called? |
Venous return |
| What is the contractile strength achieved at a given muscle length called? |
contractility; The strength of each contraction of the heart muscle |
| What is the pressure that must be overcome for the ventricles to eject blood? |
afterload - refers to the resistance the left ventricle encounters as it tries to eject blood to the body |
| What 3 factors can affect heart rates? |
ANS; hormones; ions |
| What is reduced Ca2+ blood levels called and what is the effect on the heart? |
hypocalcemia; depresses the heart |
| increased CA2+ blood levels cause what? |
tightly couple the excitation-contraction mechanism and prolong the plateau phase of the action potential |
| What interferes with depolarization by lowering resting potential and may lead to heart block and cardiac arrest? |
excessive K+ levels (hyperkalemia) |
| What is life threatening and causes the heart to beat feebly and arrhythmically? |
not enough K+ (hypokalemia) |
| What causes an abnormally fast heart rate (more than 100 beats/min) that may result from elevated body temp, stress, crtain drugs, or heart disease? |
tachycardia (heart hurry)A too fast heart beat doesnt allow enough time in diastole.So the heart chambers dont fill up enough w/blood, so the heart does not pump enough blood for the needs of the cells. |
| What is a heart rate slower than 60 beats/min called? |
Bradycardia; causes low blood pressure One of the first signs of this is called syncope, which is the same this as passing out and becoming unconscious. |
| When the pumping efficiency of the heart is so low that blood circulation is inadequate to meet tissue needs the heart is said to be in what? |
Congestive heart failure (CHF) |
| If the left side of the heart fails what occurs? |
pulmonary congestion |
| What happens if the right side of the heart fails, leading to blood stagnating in body organs and pooled fluids in tissue spaces impairing ability of body cells to obtain adequate amounts of nutrients and oxygen? |
peripheral congestion |
| what happens in the cardiac cycle during the P wave
|
depolarization of atria |
| what happens in the cardiac cycle immediately before the P wave |
heart is in diastole |
| what happens in the cardiac cycle immediately after the P wave |
contraction of atria |
| Describe what happens in the cardiac cycle during the QRS wave |
depolarization of ventricles |
| what happens in the cardiac cycle immediately after the QRS wave (S-T interval) |
contraction of ventricles |
| what happens in the cardiac cycle during the T wave |
repolarization of ventricles |
| What structure is replaced by an artificial pacemaker? |
SA node |
| List the elements of the intrinsic conduction system in order starting from the SA node |
SA node
AV node
AV bundle (Bundle of His)
L and R bundle branches
Purkinje fibers
|
| What is the bundle of His? |
atrio-ventricular bundle (AV bundle) |
| What is the amount of blood in the heart chamber that is left over from the previous contraction (end diastole), plus the amount of blood brought into the heart chamber from the venous system (the vena cava's) called? |
preload |
| the epicardium is another name for what? |
visceral layer of the serous pericardium. |
| The pericardium consists of what? |
an outer fibrous pericardium and an inner serous pericardium |
| What consists of the systole (contraction) and diastole (relaxation) of both atria, rapidly followed by the systole and diastole of both ventricles? |
A cardiac cycle |
| What are the 3 phases of the cardiac cycle? |
atrial systole, ventricular systole, and the relaxation period. |
| The act of listening to sounds within the body is called what and what instrument is usually used? |
auscultation, and it is usually done with a stethoscope |
| what heart sound is created by blood turbulence associated with the closing of the atrioventricular valves soon after ventricular systole begins |
The first heart sound (lubb) |
| What heart sound represents the closing of the semilunar valves close to the end of the ventricular systole |
The second heart sound (dupp) |
| What are the valves that prevent backflow into the atria when the ventricles are contracting and are found between the atrial and ventricular chambers on each side? |
atrioventricular (AV) valves |
| What is the left AV valve called, that consists of 2 cusps of endocardium? |
mitral or bicuspid valve |
| What is the right AV valve called that has 3 cusps? |
tricuspid valve |
| What are the tiny white collagenic cords that anchor the cusps to the ventricular walls called? |
chordae tendineae; aka heart strings |
| Where do the chordae tendineae originate from? |
the papillary muscles, small bundles of cardiac muscle that project from the myocardial wall |
| What is the period of ventricular filling into the atria known as? |
diastole |
| What is the disease process in which the body's blood vessels become increasingly occluded by plaques? |
atherosclerosis |
| What is it known as when the ventricles contract and compress blood in their chambers? |
systole |
| What anchors the flaps in a closed position to prevent blood backflow into the atria during ventricular contraction? |
chordae tendineae |
| What 2 valves are each composed of 3 pocketlike cusps and guard the bases of the 2 large arteries leaving the ventricular chambers? |
pulmonary and aortic semilunar valves |
| What kind of pump does the right side of the heart function as? |
pulmonary circulation pump |
| What does the pulmonary circulation pump side of the heart carry in the blood? |
carbon dioxide |
| What kind of pump does the left side of the heart function as? |
systemic circulation |
| What does the systemic circulation pump side of the heart carry in the blood? |
oxygen |
| What is the myocardium reinforced internally by? |
fibrous skeleton of the heart |
| What provides the functional blood supply of the heart? |
right and left coronary arteries |
| What is the myocardium largely drained by? 3 |
the great, middle and small cardiac veins |
| What does the coronary sinus and several anterior cardiac veins empty into? |
right atrium |
| What node has the highest rate of discharge and provides the stimulus for contraction? |
SA node |
| What represents the time between the beginning of atrial depolarization and ventricular depolarization in an ECG? |
the P-R interval |
| How long is the P-R interval? |
.16 to .18 seconds |
| What is the period from the beginning of ventricular depolarizarion thru repolarization and includes the time of ventricular contraction called? |
Q-T interval |
| The lining of the heart |
endocardium |
| The outermost layer of the serous pericardium |
parietal layer |
| Prevents backflow into the left ventricle |
aortic semilunar valve |
| Prevents backflow into the right atrium |
tricuspid valve |
| Serous layer covering the heart muscle |
epicardium |
| AV valve with two flaps |
mitral valve |
| Prevents backflow into the right ventricle |
pulmonary semilunar valves |
| Prevents backflow into the left atrium |
mitral valve |
Biology Lab Midterm
