Chapter 17 Lecture+Lab
Identify the structure labeled "a."
Aorta
Identify the structure
Chordae tendonea
Identify the structure labeled "f."
Mitral (bicuspid) valve
Identify the structure labeled "b."
Pulmonary semilunar valve
A damaged right bundle branch will prevent the passage of the action potential to the:
Purkinje fibers in the right ventricle.
Which component of the ECG represents the depolarization of the ventricles?
QRS complex
Predict the position of the valves during the ventricular ejection phase.
The AV valves are shut while both semilunar valves are forced open.
The long length of the cardiac action potential, at 200-300 msec, allows for:
an opportunity for the heart to fill with blood
Where should the left ventricle send blood?
aorta
If a drop of blood is located in the left ventricle, through what structure will it next pass?
aortic semilunar valve
Which is a good description of cardiac muscle fibers?
branched, uninucleate cells with intercalated discs
Which of the following volumes should be the greatest?
cardiac output (CO)
Autorhythmicity in the heart is the responsibility of:
cardiac pacemaker cells
Which vessel is part of the coronary circulation?
circumflex artery
What action causes the first heart sound heard through a stethoscope?
closing of the atrioventricular valves
The amount of blood remaining in each ventricle at the end of the ventricular ejection phase is called:
end systolic volume
What largely determines preload?
end-diastolic volume (EDV)
Which is another term for the visceral pericardium?
epicardium
There are two phases of the cardiac cycle in which all four heart valves are open: the isovolumetric contraction phase and the isovolumetric relaxation phase.
false
What ion movement changes the membrane potential in a contractile cell from negative to positive during the rapid depolarization phase?
influx of sodium ions
Identify the structure on the micrograph labeled "c."
intercalated disc
When is the S2 heart sound heard?
isovolumetric relaxation phase
The pulmonary circuit involves blood flow from the heart to the:
lungs
Identify the structure
papillary muscle
Which of the following valve closings can be auscultated during the "dupp" heart sound by placing the stethoscope at the left sternal border of the second intercostal space?
pulmonary semilunar
What vessel(s) deliver oxygenated blood to the left atrium?
pulmonary veins
Which component of the cardiac conduction system extends through the interventricular septum toward the apex of the heart?
right and left bundle branches
Identify the chamber
right ventricle
The volume of blood pumped by each ventricle in one heartbeat is known as:
stroke volume (SV)
Through which vessel is deoxygenated blood returned to the heart?
superior vena cava
What valve prevents the backflow of blood from the right ventricle into the right atrium?
tricuspid valve
The left side of the heart is often called the systemic pump due to blood flow to the body.
true
Which cranial nerves have a negative chronotropic effect on heart rate?
vagus nerves (CN X)
Both the left and right atria receive blood from:
veins
Identify the structure labeled "b."
AV node
What is the direct source of the heart sounds in a heart beat?
Blood turbulence resulting from valve closure
