A&P chapter 18
Contraction of the atria results from which wave of depolarization on the ECG tracing?
P wave
Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles?
AV node
Identify the valve found between the left atrium and left ventricle.
Bicuspid (mitral) valve
________ is to slow heart rate as ________ is to fast heart rate.
Bradycardia; tachycardia
The right ventricle pumps blood to the
right and left lungs.
Coronary veins empty into the
right atrium
The ________ deliver(s) blood to the myocardium
right coronary artery and left coronary artery
What does the QRS complex represent in the ECG wave tracing?
ventricular depolarization
The T wave on an ECG tracing represents
ventricular repolarization
Which pathology is described as a thickening and toughening of arterial walls?
arteriosclerosis
A slower-than-normal heart rate is called
bradycardia
The first heart sound ("lubb") is associated with
closing of the mitral valve
The function of the atrium is to
collect blood and pump blood to the ventricle
Blood is supplied to the myocardium by
coronary arteries
What does the ECG wave tracing represent?
electrical activity in the heart
The base of the heart is located at the bottom of the heart.
false
There are ________ pulmonary veins.
four
The pulmonary veins carry blood to the
heart
The pulmonary arteries carry blood to the
lungs
Define heart failure
Heart failure is a condition where the heart can no longer meet the oxygen and nutrient demands of peripheral tissues.
What is the function of the coronary circulation?
Provide a blood supply to the heart
Give the alternate terms for heart contraction and heart relaxation.
The alternate term for heart contraction is systole and the alternate term for heart relaxation is diastole.
Why is ventricular fibrillation fatal?
Ventricular fibrillation is fatal because the ventricles quiver and do not pump blood to the systemic circulation.
What is the ligamentum arteriosum
remnant of ductus arteriosus
Which chamber receives blood from the superior and inferior vena cavae?
right atrium
Name the four chambers of the heart.
right atrium, right ventricle, left atrium, left ventricle
Blood returning to the heart from the systemic circuit first enters the
right atrium.
Which chamber of the heart exits into the pulmonary trunk?
right ventricle
Which heart chamber pumps unoxygenated blood out the pulmonary trunk?
right ventricle
Blood returning to the heart from the pulmonary circuit first enters the
left atrium
Which heart chamber receives blood from the lungs?
left atrium
Which heart chamber receives blood from the pulmonary veins
left atrium
Identify the most muscular chamber.
left ventricle
What heart chamber pushes blood through the aortic semilunar valve?
left ventricle
Which chamber pumps oxygenated blood out the aorta to the systemic circuit?
left ventricle
The ________ has a greater workload than the ________.
left ventricle; right ventricle
Compared to the right ventricle, the left ventricle has all the following characteristics except that it
pumps a greater volume.
The portion of the tracing of an electrocardiogram, ECG, that represents ventricular depolarization is the __________.
qrs complex
At a heart rate of 60 beats/minute, a cardiac cycle lasts
1 seconds
The heart beats approximately ________ times each day.
100,000
The heart pumps approximately ________ milliliters of blood each minute.
6000
Define autorhythmicity
Autorhythmicity is the ability of the heart to contract without neural or hormonal stimulation.
Name the irregular ridges of muscle lining the ventricles.
Trabeculae carneae
Define cardiac cycle
Cardiac cycle is the period between the start of one heartbeat and the beginning of the next.
Which part of the conduction system initiates the depolarizing impulse, which spreads throughout the heart?
SA node
Which part of the intrinsic conduction system normally initiates the depolarizing impulse that causes a heartbeat?
SA node
Which of the following does NOT contribute to the partial or complete blockage of the coronary arteries that causes coronary ischemia?
a stent
What superficial landmark identifies the boundary between the left and right ventricles?
anterior interventricular sulcus
The left ventricle pumps blood to the
aorta
What occurs at "A" on the graph?
aortic semilunar valve opens
The inferior point of the heart is called the
apex
List the phases of the cardiac cycle
atrial systole, atrial diastole, ventricular systole, ventricular diastole
Identify the ear like flaps that are attached to the top chambers of the heart.
auricle
Which of these structures conduct(s) action potentials the slowest?
av node
The superior portion of the heart where major blood vessels enter and exit is the
base
The ________ valve prevents backward flow into the left atrium.
bicuspid
The pulmonary semilunar valve prevents backward flow into the
right ventricle.
What occurs at "B" on the graph?
semilunar valve closes
The normal pacemaker of the heart is located in
sinoatrial node
________ is to contraction as ________ is to relaxation.
systole; diastole
A faster-than-normal heart rate is called
tachycardia
Blood on the right never mixes with blood on the left, once the heart is fully developed.
true
The first branch off the arch of the aorta is the brachiocephalic artery in both the sheep and the human.
true
The heart is actually (one, two, or three) pumps?
two pumps
Why does tetany not occur in cardiac muscle?
Cardiac muscle has a long refractory period that continues until relaxation is well under way. As a result, another action potential cannot arrive quickly enough for summation to occur, and thus tetany cannot occur.
What fibrous structure functions to anchor the atrioventricular valves in a closed position?
Chordae tendineae
The ________ separate(s) the two ventricles.
interventricular septum
The first blood vessels to branch from the aorta are the ________ arteries.
coronary
Name the inner lining of the heart.
endocardium
