Human Physiology Exam 2 - Chapter 13
Starling's law of the heart can be stated as ________. - Any change in the rate of blood flow from the heart will be extrinsically regulated only by the autonomic nervous system. - A change in the rate of blood flow return to the heart affects the ventricular preload, which affects the stroke volume. - The rate of blood flow to and from the heart is constant and unchanging.
A change in the rate of blood flow return to the heart affects the ventricular preload, which affects the stroke volume.
During exercise, sympathetic input to the heart is increased. Stroke volume is often maintained, or even increased, even though heart rate is also increasing. How is this possible? - Sympathetic input increases ventricular contractility, thereby increasing stroke volume. - Sympathetic input decreases conduction time within the heart, decreasing the delay between atrial and ventricular contractions. - Sympathetic input increases the speed of ventricular contraction. - All of the listed responses are correct. - None of the listed responses are correct
All of the listed responses are correct
During the plateau phase of the action potential in cardiac contractile cells, ________. - sodium channels are inactivated - voltage-gated K+ channels close - calcium L-type channels are open - the membrane potential remains depolarized - All of the listed responses are correct.
All of the listed responses are correct.
End diastolic volume is influenced (directly or indirectly) by ________. - heart rate - preload - afterload - sympathetic nerve activity - All of the listed responses are correct.
All of the listed responses are correct.
Functions that occur in the cardiovascular system include ________. - transport - endocrine - sensory - All of the listed responses are correct.
All of the listed responses are correct.
Which of the following statements about the structure of the heart is (are) true? - The left ventricular wall is thicker than the right. - The structure of the atrioventricular and semilunar valves helps to ensure that blood flows in only one direction through the heart. - The innermost layer of epithelial cells, the endothelium, lines the inside of the entire cardiovascular system. - The structure of the atrioventricular and semilunar valves helps to ensure that blood flows in only one direction through the heart and the innermost layer of epithelial cells, the endothelium, lines the inside of the entire cardiovascular system. - All of the listed responses are correct.
All of the listed responses are correct.
Which of the following statements about the systemic circuit is true? - Each successive organ in the circuit receives less oxygen than the one before it. - Blood flow to each organ can be independently regulated. - Systemic capillaries allow for oxygen loading at the lungs. - The right ventricle pumps blood to the systemic circuit.
Blood flow to each organ can be independently regulated.
Abnormalities within the SA node can cause which of the following symptoms? - An increased P-Q interval - Bradycardia or tachycardia - Ventricular fibrillation
Bradycardia or tachycardia
Calcium is removed from the cytosol of cardiac muscle cells by each of the following mechanisms except for ________. - Ca2+ ATPases in the sarcoplasmic reticulum - Ca2+ leak channels in the plamsa membrane - Ca2+/Na+ exchangers in the plasma membrane - Ca2+ ATPases in the plasma membrane
Ca2+ leak channels in the plamsa membrane
During the slow depolarization of a pacemaker potential, membrane permeability increases for which ion? - Calcium - Chloride - Sodium - Potassium
Calcium
Which of the following is (are) the same for the left and right ventricles? - Oxygen concentration in the blood - Carbon dioxide concentration in the blood - Cardiac output, heart rate, and stroke volume
Cardiac output, heart rate, and stroke volume
Which type of membrane junctions are located at intercalated disks? - Tight junctions and desmosomes - Adherens junctions and tight junctions - Gap junctions and tight junctions - Gap junctions and desmosomes
Gap junctions and desmosomes
Which components does the cardiovascular system comprise? - Heart, lungs, blood vessels - Heart, lungs, blood - Lungs, blood vessels, blood - Heart, blood vessels, blood
Heart, blood vessels, blood
When someone begins to exercise, the working tissue needs an increased delivery of blood to obtain the oxygen and nutrients necessary for the maintenance of the increased metabolism. Which of the following occurs to help enhance the blood flow to the working tissue? - Decreased heart rate - Increased heart rate and stroke volume - Decreased stroke volume - Increased release of acetylcholine
Increased heart rate and stroke volume
Electrical signaling in the heart begins in the SA node because ________. - it is on the right side of the heart - it has the fastest conduction velocity - it depolarizes the fastest - it has the most superior position in the heart
It depolarizes the fastest
Stenosis (scarring and thickening) in the bicuspid valve would directly affect ________. - pumping of blood into systemic circulation - right ventricular filling - left ventricular filling - movement of blood into pulmonary circulation
Left ventricular filling
Which of the following may increase heart rate? - Norepinephrine - Acetylcholine - Insulin - Potassium
Norepinephrine
Which of the following statements is false? - Only a small percentage of heart muscle cells are autorhythmic. - Pacemaker cells generate action potentials in the absence of input from the nervous system. - The AV node can initiate an action potential. - Only the SA node can initiate an action potential.
Only the SA node can initiate an action potential.
Which correlation between the electrical signals of the ECG and the mechanical events of the cardiac cycle is correct? - QRS complex — period of ventricular relaxation - QRS complex — initiation of atrial contraction - P-R interval — period of atrial contraction - T-P interval — period of ventricular contraction
P-R interval — period of atrial contraction
How do pacemaker cells differ from contractile cells? - Pacemaker cells are nerve cells located in the heart. - Only pacemaker cells have calcium channels. - Pacemaker cells are autorhythmic and do not contract. - Only pacemaker cells have sodium channels.
Pacemaker cells are autorhythmic and do not contract.
Which of the following is true regarding pulmonary circulation? - Pulmonary arteries carry oxygenated blood away from the heart. - Pulmonary arteries carry deoxygenated blood to the lungs. - Pulmonary veins carry oxygenated blood away from the heart. - Pulmonary veins carry deoxygenated blood to the heart.
Pulmonary arteries carry deoxygenated blood to the lungs.
Which of the following observations on an electrocardiogram (ECG) would be expected when a person begins to exercise? - Longer P-R interval - Shorter T-P interval - Disappearance of the P wave - There would be no changes on an ECG because the electrical signals are always constant.
Shorter T-P interval
The second heart sound occurs during which aspect of the ECG? - P wave - QRS complex - PR segment - T wave
T wave
Which nerve provides parasympathetic supply to the heart? - Spinal nerve T1 - Spinal nerve T2 - Spinal nerve T3 - The vagus nerve
The vagus nerve
Why is the left ventricle muscle thicker than the right ventricle muscle? - There is no difference in thickness between the left and right ventricle muscle mass. - This difference is due to the greater pressure that the left ventricle has to generate to pump blood to all of the organs of the body. - This difference is due to the greater pressure that the right ventricle has to generate to pump blood to the lungs. - This difference is due to the lesser volume of blood that the right ventricle has to pump compared to the left ventricle.
This difference is due to the greater pressure that the left ventricle has to generate to pump blood to all of the organs of the body.
What is the function of the heart valves? - To pump blood to the proper chamber or circuit. - To passively keep blood flowing in the proper direction. - To block blood from entering the coronary circuit. - To pump and keep blood flowing in the proper direction.
To passively keep blood flowing in the proper direction.
Which of the following mechanical events occurs as a result of the electrical events that produce the QRS complex in an electrocardiogram (ECG)? - Atrial diastole - Ventricular diastole - Atrial systole - Ventricular systole - Ventricular depolarization
Ventricular systole
The actions of norepinephrine and acetylcholine on pacemaker cells is similar in that both transmitters ________. - activate G proteins and change intracellular calcium channels - bind to ligand-gated ion channels and open sodium channels - utilize the same second messenger system - bind to fast ligand-gated ion channels and open potassium channels
activate G proteins and change intracellular calcium channels
The heart chambers which receive blood flow from the systemic and pulmonary circuits are called ________. - atria - ventricles - cardiopulmonary - vasculature
atria
What does the P wave of the ECG represent? - atrial depolarization - ventricular depolarization - ventricular repolarization - the period of time when the entire heart is isoelectric
atrial depolarization
Trace the path of a red blood cell through the heart, starting in the right ventricle: a. left atrium b. right atrium c. left ventricle d. pulmonary circuit e. systemic circuit - a, b, c, d, e - e, d, c, b, a - d, a, c, e, b, - b, e, a, c, d
d, a, c, e, b,
Place the following structures involved in cardiac impulse conduction in the correct order: a. bundle of His b. AV node c. Purkinje fibers d. SA node - a, b, c, d - d, c, b, a - d, b, a, c - b, d, a, c
d, b, a, c
Parasympathetic activity decreases nodal rate of depolarization by ________. - decreasing the flow of sodium into the cytosol - decreasing the flow of calcium into the cytosol - increasing the rate of myosin ATPase activity - increasing the flow of calcium into the cytosol
decreasing the flow of calcium into the cytosol
The pulmonary arteries carry ________. - oxygenated blood away from the lungs - deoxygenated blood toward the heart - oxygenated blood away from the heart - deoxygenated blood towards the lungs
deoxygenated blood towards the lungs
Ventricular contractility is enhanced by ________. - decreased atrial pressure - decreased afterload - epinephrine - acetylcholine
epinephrine
In contrast to most other types of excitable cells, cardiac contractile cells ________. - have stable resting potentials - repolarize due to an efflux of K+ - have a plateau phase in the action potential - show an increase in PNa during the initial phase (phase 0) of the action potential
have a plateau phase in the action potential
Cardiac output is increased by ________. - increasing venous return and increasing arterial pressure - increasing stroke volume and decreasing heart rate - increasing stroke volume and increasing heart rate - decreasing venous return and increasing arterial pressure
increasing stroke volume and increasing heart rate
The aorta carries ________. - deoxygenated blood away from the lungs - deoxygenated blood toward the heart - oxygenated blood toward the lungs - oxygenated blood away from the heart
oxygenated blood away from the heart
In the electrocardiogram (ECG), the T wave corresponds to the ________. - depolarization of the atria - depolarization of the ventricles - repolarization of the atria - repolarization of the ventricles
repolarization of the ventricles
The pulmonary semilunar valve opens in response to ________. - right ventricle pressure exceeding pulmonary vein pressure - left ventricle pressure exceeding pulmonary vein pressure - right ventricle pressure exceeding pulmonary artery pressure - left ventricle pressure exceeding pulmonary artery pressure
right ventricle pressure exceeding pulmonary artery pressure
Regarding ventricular volumes ________. - the larger the end diastolic volume, the larger the stroke volume becomes - all the blood contained in the ventricles enters the vasculature during the ejection phase of the cardiac cycle - an increase in the force of atrial contraction increases the end systolic volume
the larger the end diastolic volume, the larger the stroke volume becomes
According to the anatomical definition, an artery is a blood vessel that ________. - transports blood toward the heart - transports blood away from the heart - transports oxygenated blood - None of the listed responses is correct.
transports blood away from the heart
During isovolumetric contraction ________. - ventricular pressure is increasing while the volumes is constant - ventricular pressure is less than atrial pressure - atrioventricular valves are open - blood is flowing from the ventricles into the aorta and pulmonary arteries
ventricular pressure is increasing while the volumes is constant
