Chapter 20 Canvas Quiz

Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing. A) T wave B) QRS complex C) R-T interval D) P-R interval E) P wave

B) QRS complex

Depolarization of the ventricles is represented on an electrocardiogram by the A) S wave B) QRS complex C) T wave D) P wave E) PR complex

B) QRS complex

The long plateau phase of the cardiac muscle action potential is due to... A) decrease in the amount of calcium diffusing across the membrane B) calcium channels remaining open C) increased membrane permeability to sodium ions D) increased membrane permeability to potassium ion E) movement of fewer sodium ions across the cell membrane

B) calcium channels remaining open

Most of the middle layer in the heart wall is composed of... A) epithelial cells B) cardiac muscle cells C) chondrocytes D) smooth muscle cells E) fibrocytes

B) cardiac muscle cells

What occurs at the circle labeled "7" on the graph? A) isovolumetric ventricular contraction B) isovolumetric ventricular relaxation C) sympathetic stimulation D) ventricular ejection E) ventricular filling

B) isovolumetric ventricular relaxation

Rupture of the papillary muscles in the left ventricle may result in... A) pulmonary valve regurgitation B) mitral valve prolapse C) aortic valve prolapse D) tricuspid prolapse E) tricuspid regurgitation

B) mitral valve prolapse

Contractions of the papillary muscles A) close the semilunar valves B) close the atrioventricular valves C) eject blood from the ventricles D) eject blood from the atria into the ventricles E) prevent the atrioventricular valves from reserving into the atria

E) prevent the atrioventricular valves from reserving into the atria

Blood returning to the heart from the systemic circuit first enters the... A) conus arteriosus B) right ventricle C) left ventricle D) left atrium E) right atrium

E) right atrium

Figure 20-2 Cardiac Cycle; Use figure 20-2 to answer the following questions: What occurs at the circle labeled "3" on the graph? A) isovolumetric relaxation B) ventricular ejection C) atrial systole D) atrial diastole and ventricle systole E) atrial ejection

D) atrial diastole and ventricle systole

The amount of blood remaining in the ventricle when the semilunar valve closes is the... A) stroke volume B) ejection fraction C) start-diastolic volume D) end-systolic volume E) end-diastole volume

D) end-systolic volume

Which chamber receives oxygenated blood from the pulmonary circuit? A) 16 B) 5 C) both 5 and 26 D) 13 E) 10

A) 16

The right pulmonary veins carry ________ blood to the ________. A) oxygenated; left atrium B) deoxygenated; superior vena cava C) oxygenated; right lung D) deoxygenated; right atrium E) deoxygenated; left atrium

A) oxygenated; left atrium

The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as... A) pericarditis B) cardiomyopathy C) cardiac tamponade D) pleural effusion E) mitral valve prolapse

C) cardiac tamponade

If the pacemaker cells in the SA node become more permeable to potassium ions, the... A) cells will hyperpolarize B) heart rate will increase C) cells will depolarize D) heart rate decrease and cells will hyperpolarize E) heart rate will decrease

D) heart rate will decrease and cells will hyperpolarize

Figure 20-1 The Heart; Use figure 20-1 to answer the following questions:; Identify the structure labeled "19"? A) ligamentum arteriosum B) bicuspid valve C) aortic semilunar valve D) pulmonary semilunar valve E) tricuspid valve

D) pulmonary semilunar valve

What volume is labeled "E" on the graph? A) cardiac output B) end-systolic C) end-diastolic volume D) stroke volume E) total cardiac volume

D) stroke volume

The heart pumps approximately ________ liters of blood each day. A) 15,000 B) 20,000 C) 50,000 D) 100,000 E) 8,000

E) 8,000

When heart rate increases, the time spent in... A) diastole increase B) isovolumetric contraction increases C) systole increase D) all phases decreases but most of the decrease is during systole E) all phases decreases but most of the decrease is during diastole

E) all phases decreases but most of the decrease is during diastole

Which of the following are involved in the pulmonary circuit? A) superior vena cava, right atrium, left ventricle B) right ventricle, pulmonary veins, aorta C) left ventricle, pulmonary veins, right atrium D) inferior vena cava, right atrium, aorta E) right ventricle, pulmonary trunk, left atrium

E) right ventricle, pulmonary trunk, left atrium

Tetanic muscle contractions don't occur in a normal cardiac muscle because... A) cardiac muscle tissue contracts on its own B) neural stimulation is lacking C) the refractory period ends before the muscle reaches peak tension D) potassium channels outnumber sodium channels E) the refractory period lasts until the muscle relaxes

E) the refractory period lasts until the muscle relaxes