12 The Cardiovascular System: The Heart
If the connection between the SA node and AV node becomes blocked, A) the ventricles will beat faster. B) the ventricles will beat independently of the atria. C) the ventricular rate of contraction will not be affected. D) the stroke volume will increase. E) tachycardia will occur
B) the ventricles will beat independently of the atria
The heart wall is composed of ________ layers of tissue. A) two B) three C) four D) five E) six
B) three
The maximum rate of contraction in normal cardiac muscle fibers is ________ per minute. A) 80 B) 140 C) 200 D) 250 E) 300+
C) 200
The following is a list of vessels and structures that are associated with the heart. 1. right atrium 2. left atrium 3. right ventricle 4. left ventricle 5. vena cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins What is the correct order for the flow of blood entering from the systemic circulation? A) 1, 2, 7, 8, 3, 4, 6, 5 B) 1, 7, 3, 8, 2, 4, 6, 5 C) 5, 1, 3, 7, 8, 2, 4, 6 D) 5, 3, 1, 7, 8, 4, 2, 6 E) 5, 1, 3, 8, 7, 2, 4, 6
C) 5, 1, 3, 7, 8, 2, 4, 6
The amount of blood the heart pumps in one minute is the A) HR. B) SV. C) CO. D) EDV. E) ESV
C) CO
The ________ circuit directly supplies blood to the myocardium. A) systemic B) cardiac C) coronary D) pulmonary E) none of the above
C) coronary
The great and middle cardiac veins drain blood into the A) superior vena cava. B) inferior vena cava. C) coronary sinus. D) coronary sulcus. E) aorta
C) coronary sinus
Cardiac muscle is similar to skeletal muscle in the A) arrangement of the t-tubules. B) arrangement of the sarcoplasmic reticulum. C) presence of striations. D) presence of intercalated discs. E) all of the above
C) presence of striations
Folding of the valves in the wrong direction is called A) myositis. B) carditis. C) prolapse. D) stenosis. E) infarction
C) prolapse
Blood vessels in the cardiovascular system are subdivided into the A) lymphatic and blood circuits. B) dorsal aorta and venae cavae. C) systemic and pulmonary circuits. D) cardiac and vascular circuits. E) none of the above
C) systemic and pulmonary circuits
The second heart sound is heard when A) the AV valves open. B) the AV valves close. C) the semilunar valves close. D) the atria contract. E) blood enters the aorta
C) the semilunar valves close
Blood from the systemic circulation returns to the heart by way of the A) coronary sinus. B) pulmonary veins. C) venae cavae. D) aorta. E) pulmonary arteries
C) venae cavae
According to Starling's law of the heart, the cardiac output is directly related to the A) size of the ventricle. B) heart rate. C) venous return. D) thickness of the myocardium. E) amount of blood in the cardiovascular system
C) venous return
The semilunar valves prevent backflow into the A) atria. B) aorta. C) ventricles. D) pulmonary trunk. E) venae cavae
C) ventricles
The QRS wave on an ECG tracing represents A) atrial depolarization. B) atrial repolarization. C) ventricular depolarization. D) ventricular repolarization. E) ventricular contraction
C) ventricular depolarization
HR x SV = _________________________
CO (cardiac output)
The great vessels of the heart are located at the _________________________ of the heart
base
A slower-than-normal heart rate is called _________________________
bradycardia
Each cardiac muscle cell is bound to its neighboring cells at sites called __________________
intercalated discs
The left border of the heart is formed by the _______________ and a small portion of the _______________
left ventricle; left atrium
In a condition called _________________________, the cusps of the bicuspid valve do not close properly
mitral valve prolapse
The muscle layer of the heart is the ______________
myocardium
The heart is surrounded by the _________________________ cavity
pericardial
The amount of muscle stretch during diastole is called the _____________
preload
Blood returning from the systemic circulation enters the A) right atrium. B) right ventricle. C) left atrium. D) left ventricle. E) pulmonary circulation
right atrium
The right atrium receives blood from the systemic circuit and passes it to the ______________
right ventricle
Relaxation of the ventricles is called A) ventricular diastole. B) ventricular systole. C) depolarization. D) hyperpolarization. E) none of the above
A) ventricular diastole
In which situation would the filling time be the greatest? A) when heart rate is slow B) when heart rate is fast C) when the force of contraction is decreased D) when the difference between the end diastolic volume and the end systolic volume is small E) when calcium channel blockers are present
A) when heart rate is slow
The amount of blood in each ventricle during isovolumetric relaxation is equal to the A) EDV. B) ESV. C) SV. D) HR. E) CO
B) ESV
The amount of blood the heart beats in one contraction is the A) HR. B) SV. C) CO. D) EDV. E) ESV
B) SV
Under conditions of hypocalcemia, A) cardiac muscle cells become lethargic. B) cardiac muscle contraction is weak. C) cardiac muscles become extremely excitable. D) cardiac muscle cells remain the same. E) none of the above
B) cardiac muscle contraction is weak
The average pressure in the right ventricle is ________ the pressure in the left ventricle. A) the same as B) considerably lower than C) slightly lower than D) slightly higher than E) much higher than
B) considerably lower than
The pulmonary arteries carry blood to the A) heart. B) lungs. C) brain. D) intestines. E) liver
B) lungs
The cardioinhibitory center controls activities of the ________ neurons. A) ganglionic B) parasympathetic C) postganglionic D) preganglionic E) sympathetic
B) parasympathetic
Which of the following is greater? A) the conduction velocity along a normal myocardial fiber B) the conduction velocity along a Purkinje fiber C) the conduction velocity through the heart skeleton D) the conduction velocity in the heart valves E) None of the above conducts a signal
B) the conduction velocity along a Purkinje fiber
The _________________________ circuit carries blood to and from all parts of the body except the lungs
systemic
The contraction phase of the cardiac cycle is called ___________________
systole
_______________ are blood vessels that usually return blood to the heart
veins
The amount of blood returning to the heart is the _____________________
venous return
The amount of blood in each ventricle during isovolumetric contraction is equal to the A) HR. B) ESV. C) SV. D) CO. E) EDV
E) EDV
The cardiac skeleton of the heart functions to A) physically isolate the muscle fibers of the atria from those of the ventricles. B) maintain the normal shape of the heart. C) help distribute the forces of cardiac contraction. D) A and C only E) all of the above
E) all of the above
When a chamber fills with blood and is preparing to begin the next cardiac cycle, that chamber is A) in systole. B) in diastole. C) repolarizing. D) depolarizing. E) both B and C
E) both B and C
The innermost layer of the heart wall is the A) mediastinum. B) parietal pericardium. C) epicardium. D) myocardium. E) endocardium
E) endocardium
The wall between the atria is the A) ventricle. B) coronary sinus. C) coronary sulcus. D) auricle. E) interatrial septum
E) interatrial septum
During ventricular diastole, A) the atria are contracting. B) blood is entering the ventricle. C) the AV valves are closed. D) the pressure in the ventricles increases. E) the ventricles are relaxed
E) the ventricles are relaxed
Which of the following is true regarding cardiac muscle? A) Neither summation nor tetany can occur. B) Both summation and tetany can occur. C) Summation, but NOT tetany, can occur. D) Tetany, but NOT summation, can occur. E) none of the above
A) Neither summation nor tetany can occur
Depolarization of the atria is represented on an electrocardiogram by the A) P wave. B) T wave. C) S wave. D) QRS complex. E) PR complex
A) P wave
The ________ of the heart is(are) located in the walls of the ventricles. A) Purkinje fibers. B) SA node. C) AV node. D) bundle branches. E) bundle of His
A) Purkinje fibers
Select the correct order of stimulation in the nodal pathways. A) SA node, AV node, AV bundle, Purkinje fibers B) SA node, AV bundle, AV node, Purkinje fibers C) AV node, SA node, AV bundle, Purkinje fibers D) Purkinje fibers, SA node, AV node, AV bundle E) none of the above
A) SA node, AV node, AV bundle, Purkinje fibers
EDV minus ESV equals A) SV. B) HR. C) CO. D) CO max. E) BMR
A) SV
The semilunar valve of the left side of the heart prevents backflow from the A) aorta. B) pulmonary trunk. C) pulmonary veins. D) right ventricle. E) left ventricle
A) aorta
Blood is carried away from the heart by A) arteries. B) veins. C) arterioles. D) capillaries. E) venules
A) arteries
Atrioventricular valves prevent backflow into the A) atria. B) ventricles. C) venae cavae. D) aorta. E) pulmonary trunk
A) atria
The function of an atrium is to A) collect blood. B) pump blood to the lungs. C) pump blood into the systemic circuit. D) pump blood to the heart muscle. E) all of the above
A) collect blood
Preload directly determines A) end diastolic volume. B) end systolic volume. C) stroke volume. D) cardiac output. E) cardiac reserve
A) end diastolic volume
The left and right coronary arteries carry blood to the A) heart. B) head. C) brain. D) intestines. E) liver
A) heart
The right ventricle pumps blood to the A) lungs. B) left ventricle. C) left atrium. D) systemic circuit. E) none of the above
A) lungs
The atrioventricular valve on the left side of the heart is the A) mitral valve. B) cuspid valve. C) tricuspid valve. D) pulmonary semilunar valve. E) aortic semilunar valve
A) mitral valve
In rheumatic heart disorder, the bicuspid valves close incompletely, leading to A) mitral valve prolapse. B) semilunar valve prolapse. C) ventricular stenosis. D) atrioventricular valve prolapse. E) overriding aorta
A) mitral valve prolapse
The loose-fitting sac around the heart is lined by the A) parietal pericardium. B) epicardium. C) endocardium. D) parietal myocardium. E) parietal endocardium
A) parietal pericardium
Heart valves open and close because of A) pressure differences. B) heart contractions. C) signals from the SA node. D) contractions of the papillary muscles. E) the moderator band
A) pressure differences
The first blood vessels to branch from the pulmonary trunk are the A) pulmonary arteries. B) bronchial arteries. C) circumflex arteries. D) carotid arteries. E) subclavian arteries
A) pulmonary arteries
The left atrium receives blood from the A) pulmonary veins. B) pulmonary trunk. C) aorta. D) inferior vena cava. E) arteries and veins
A) pulmonary veins
The functions of the venae cavae include which of the following? A) returning blood to the atria B) pumping blood into circulation C) removing excess fluid from the heart chambers D) anchoring the heart to surrounding structures E) preventing expansion of the heart
A) returning blood to the atria
The marginal artery branches off the A) right coronary artery. B) left coronary artery. C) interventricular artery. D) coronary sinus. E) aorta
A) right coronary artery
Cardiac output would be greatest when A) sympathetic stimulation of the heart increases. B) parasympathetic stimulation of the heart increases. C) resting in bed. D) the vagus nerve is sending many impulses. E) None of the above increases CO
A) sympathetic stimulation of the heart increases
Which of the following is greatest during left ventricular systole? A) the pressure in the ventricle B) the pressure in the aorta C) the pressure in the left atrium D) the pressure in the right ventricle E) the pressure in the right atrium
A) the pressure in the ventricle
Which of the following is longest in duration of time? A) the refractory period of cardiac muscle B) the refractory period of skeletal muscle C) contraction of skeletal muscle D) contraction of cardiac muscle E) the P wave
A) the refractory period of cardiac muscle
The following are various components of the conducting system of the heart: 1. Purkinje cells 2. AV bundle 3. AV node 4. SA node 5. bundle branches The sequence in which an action potential would move through this system is A) 1, 4, 3, 2, 5. B) 3, 2, 4, 5, 1. C) 3, 5, 4, 2, 1. D) 4, 3, 2, 5, 1. E) 4, 2, 3, 5, 1.
D) 4, 3, 2, 5, 1
Blood flowing from the left atrium to the left ventricle flows through the ________ valve. A) bicuspid B) left AV C) mitral D) all of the above E) none of the above
D) all of the above
The ________ accelerates the heart rate when the walls of the right atrium are stretched. A) venous return B) stroke volume C) cardiac output D) atrial reflex E) cardiac cycle
D) atrial reflex
The tricuspid valve is located A) in the opening of the aorta. B) in the opening of the pulmonary trunk. C) where the vena cavae join the right atrium. D) between the right atrium and right ventricle. E) between the left atrium and left ventricle
D) between the right atrium and right ventricle
The amount of blood the heart pumps in one minute is A) end diastolic volume. B) end systolic volume. C) stroke volume. D) cardiac output. E) cardiac reserve
D) cardiac output
The three layers of the heart wall are the A) skeletal, smooth, and cardiac. B) visceral, parietal, and fibrous. C) arteries, veins, and capillaries. D) epicardium, myocardium, and endocardium. E) none of the above
D) epicardium, myocardium, and endocardium
The skeleton of the heart consists of A) a bone within the myocardium. B) a bone in the interatrial septum. C) a bone in the interventricular septum. D) fibrous connective tissue that surrounds the atrioventricular orifices. E) fibrous connective tissue in the aorta
D) fibrous connective tissue that surrounds the atrioventricular orifices
The heart lies in the A) pleural cavity. B) peritoneal cavity. C) abdominopelvic cavity. D) mediastinum
D) mediastinum
The T wave of the ECG corresponds to A) atrial depolarization. B) atrial diastole. C) ventricular systole. D) ventricular repolarization. E) none of the above
D) ventricular repolarization
The push of blood pressure in the great arteries back toward the heart is called ________________
afterload
When arteries connect to one another, it is called an arterial ______________
anastomosis
Abnormal patterns of cardiac activity are known as _________________
arrhythmias
The superior chambers of the heart are called _____________ and the inferior chambers are the _____________
atria; ventricles
The property of heart muscle to contract in the absence of neural or hormonal stimulation is called ________________________
automaticity
The period between the start of one heartbeat and the beginning of the next is called the __________________
cardiac cycle
The internal connective tissue network of the heart is called the _________________
cardiac skeleton
Cardiac muscle cells are called ___________________
cardiomyocytes
Carbon dioxide, pH, and oxygen levels in blood are monitored by receptors called __________________
chemoreceptors
Atherosclerosis of coronary vessels leads to _____________________
coronary artery disease
A procedure in which a small section of a peripheral vein is used to create a detour around an obstruction in a coronary artery is called ________________
coronary bypass surgery
The term for reduced blood flow to the cardiac muscle is ______________________
coronary ischemia
The relaxation phase of the cardiac cycle is called _______________
diastole
In a condition called heart _________________________, the heart is unable to maintain an adequate cardiac output
failure