Chapter 25 Quiz

Question 1

Heart muscle differs from skeletal muscle tissue by being able to generate:

Answer 1

action potentials.

Question 2

Heart muscle, or myocardium, has the unique capability of

Answer 2

generating and conducting electrical impulses

Question 3

Heart muscle similarities to skeletal muscle include

Answer 3

contractility, calcium influx, and actin-myosin (sarcomeres) binding.

Question 4

During ventricular systole, closure of the atrioventricular (AV) valves coincides with

Answer 4

isovolumetric contraction.

Question 5

Ventricular systole is divided into two parts

Answer 5

isovolumetric and ejection period

Question 6

isovolumetric contraction when

Answer 6

the AV valves close and ventricles fill

Question 7

ejection period

Answer 7

when the semilunar valves open and blood is ejected through the aortic valve into circulation.

Question 8

Preload represents the volume work of the heart and is largely determined by:

Answer 8

venous blood return.

Question 9

Preload represents

Answer 9

the amount of blood the heart must pump with each beat

Question 10

Pressure (resistance), contraction, and ventricular emptying are all related to

Answer 10

afterload

Question 11

A patient has entered hypovolemic shock after massive blood loss in a car accident. Many of the patient’s peripheral blood vessels have consequently collapsed. How does the Laplace law account for this pathophysiologic phenomenon?

Answer 11

Blood pressure is no longer able to overcome vessel wall tension.

Question 12

In circulatory shock there is a decrease in blood volume and

Answer 12

vessel radii

Question 13

A male patient with a history of angina has presented to the emergency department with uncharacteristic chest pain and his subsequent ECG reveals T-wave elevation. This finding suggests an abnormality with which of the following aspects of the cardiac cycle?

Answer 13

Ventricular repolarization

Question 14

The T wave on electrocardiography (ECG) corresponds to

Answer 14

ventricular repolarization

Question 15

Atrial depolarization is represented by the

Answer 15

P wave

Question 16

ventricular depolarization is represented by the

Answer 16

QRS complex

Question 17

The isoelectric or zero line between the P wave and the Q wave represents

Answer 17

depolarization of the AV node, bundle branches, and Purkinje system.

Question 18

A patient who lives with a diagnosis of angina pectoris has taken a sublingual dose of nitroglycerin to treat the chest pain he experienced while mowing his lawn. This drug has resulted in a release of nitric oxide, which will have what effect?

Answer 18

Smooth muscle relaxation of vessels

Question 19

Nitroglycerin produces its effects by releasing

Answer 19

nitric oxide in vascular smooth muscle

Question 20

nitroglycerin results in

Answer 20

relaxation of the muscle and increased blood flow

Question 21

Release of which of the following humoral factors will result in vasodilation?

Answer 21

Histamine

Question 22

Histamine has a powerful _______ effect

Answer 22

vasodilator

Question 23

histamine has the ability to

Answer 23

increase capillary permeability, allowing leakage of both fluid and plasma proteins into the tissues.

Question 24

Norepinephrine, angiotensin II, and serotonin are all potent

Answer 24

vasoconstictors

Question 25

The difference between the end-diastolic and end-systolic volumes is the

Answer 25

stroke volume

Question 26

Cardiac output is determined by

Answer 26

stroke volume and heart rate

Question 27

Ejection fraction is the volume ejected from the

Answer 27

left ventricle

Question 28

Cardiac reserve is determined by

Answer 28

cardiac output

Question 29

A large increase in heart rate can cause:

Answer 29

decreased stroke volume

Question 30

The tissue factor that contributes to humoral control of blood flow by causing vasoconstriction is:

Answer 30

serotonin

Question 31

Histamine, bradykinin, and nitric oxide cause _______ of blood vessels.

Answer 31

vasodilation

Question 32

In the days following a tooth cleaning and root canal, a patient has developed an infection of the thin, three-layered membrane that lines the heart and covers the valves. What is this patient's most likely diagnosis?

Answer 32

Endocarditis

Question 33

The endocardium is a

Answer 33

thin, three-layered membrane that lines the heart and covers the valves

Question 34

Following several weeks of increasing fatigue and a subsequent diagnostic work-up, a patient has been diagnosed with mitral valve regurgitation. Failure of this heart valve would have which of the following consequences?

Answer 34

Backflow from the left ventricle to left atrium

Question 35

Harmful effects on cardiac action potential are most likely to result from a deficit of which of the following electrolytes?

Answer 35

Potassium

Question 36

the ions directly involved in the cardiac action potential are

Answer 36

sodium, calcium and potassium

Question 37

Turbulent blood flow can be caused by a number of factors, including:

Answer 37

increased velocity.

Question 38

Vessel length affects the _____ of flow rather than the type of flow.

Answer 38

rate

Question 39

Long-term autoregulation of local blood flow in the microcirculation is mediated by:

Answer 39

collateral circulation

Question 40

Short-term (increase/decrease) autoregulation is mediated by mechanisms that include

Answer 40

arteriovenous shunting of blood, the metabolic needs of the tissues, and autonomic nervous system controls.

Question 41

A patient with a diagnosis of secondary hypertension has begun to experience signs and symptoms that are ultimately suggestive of decreased cardiac output. Which of the following factors that determine cardiac output is hypertension likely to affect most directly?

Answer 41

Afterload

Question 42

In the arterial-venous circulatory system, pressure is inversely related to:

Answer 42

volume

Question 43

Arterial circulation contains a lower percentage of total blood volume and has higher pressure than the venous circulation, which contains the majority of

Answer 43

circulating blood

Question 44

Flow is related to

Answer 44

viscosity

Question 45

radius is related to

Answer 45

wall tension

Question 46

Velocity is inversely proportional to the

Answer 46

cross-sectional area of the vessel.

Question 47

The parasympathetic nervous system causes a slowing of the heart rate by increasing:

Answer 47

vagus nerve activity

Question 48

Norepinephrine is the main neurotransmitter for

Answer 48

sympathetic neurons

Question 49

Which of the following factors is the primary governor of the local control of blood flow?

Answer 49

The nutritional needs of the tissue involved

Question 50

Action potentials, cardiac contractility, and preload are all aspects of

Answer 50

overall circulation

Question 51

Similarly, feedback from arterial baroreceptors and chemoreceptors inform the _____ ____ of systemic blood pressure, but not the local control of blood flow.

Answer 51

neural control