Chapter 18: The cardiovascular System: the heart (book)
mesoderm
Guided by powerful signaling molecules, the human heart develops from __________.
the number of times the heart beats in one minute
The cardiac cycle includes all of the following events EXCEPT __________.
functional syncytium
The contractile cardiac muscle fibers of the myocardium behave as a single, coordinated unit called a __________.
aorta
The coronary arteries arise from the __________.
squamous epithelium
The endocardium is composed of __________.
right atrium
The inferior vena cava brings blood from the lower regions of the body and empties into the __________.
the left ventricle
What part of the heart is considered the systemic circuit pump?
left ventricle into the left atrium
When the mitral valve closes, it prevents the backflow of blood from the __________.
epicardium, myocardium, endocardium
Which is the correct sequence of layers in the heart wall, starting with the outer layer?
cardiac output
the amount of blood pumped by each ventricle in one minute
Cardiac cycle
the events associated with blood flow through the heart during one complete heartbeat
mitral (bicuspid) valve
valve between the left atrium and left ventricle
tricuspid valve
valve between the right atrium and right ventricle
incompetent cardiac valve
A doctor puts his stethoscope on a patient's chest over the location of the heart and hears an abnormal swishing sound. Which of the following conditions is the best diagnosis for the patient's condition?
an enlarged ventricle
An enlarged R wave on an ECG would indicate __________.
the amount of blood pumped out of each ventricle in one minute (cardiac output = heart rate × stroke volume)
Cardiac output is __________.
left ventricle and flows directly to the aorta
During pulmonary circulation, blood leaves the __________.
left atrium; left ventricle
Freshly oxygenated blood is delivered to the __________, and then it passes into the __________ to be pumped to the body tissues (systemic circuit).
right atrium, right ventricle, lungs, left atrium, left ventricle
From the perspective of blood returning from the systemic circuit, identify the correct sequence of blood flow through the chambers of the heart.
True
In the fetus, blood from the left and right sides of the heart normally mix. (true or false)
left atrium
Into which chamber of the heart do the pulmonary veins deliver blood?
atrial depolarization
The P wave of an electrocardiogram represents __________.
chordae tendineae
The __________ are attached to the AV valve flaps.
Vagus
The __________ nerve carries parasympathetic fibers to the sinoatrial (SA) node.
the muscle cell will not respond to a stimulus of any strength
The absolute refractory period refers to the time during which __________.
endocardium
The lining of the heart chambers is called the __________.
left ventricle
The most muscular chamber of the heart is the __________.
pacemaker cells
The noncontractile cardiac muscle cells that initiate their own depolarization and cause depolarization of the rest of the heart are called __________.
SA node
The normal pacemaker of the heart is the __________.
Slow down impulses so that the atria can contract to fill the adjacent ventricles with blood
The role of the atrioventricular node (AV node) is to __________.
closure of the semilunar valves
The second heart sound (the "dup" of "lub-dup") is caused by the __________.
parietal layer of the serous pericardium
The structure just deep to the fibrous pericardium is the __________.
atria
The superior chambers of the heart are called the __________.
systole
contraction
aortic semilunar valve
prevents backflow of blood into the left ventricle
diastole
relaxation
anterior interventricular artery
supplies blood to the interventricular septum and anterior walls of both ventricles
right marginal artery
supplies blood to the lateral right side of the myocardium
circumflex artery
supplies blood to the left atrium and posterior walls of the left ventricle
stroke volume
the volume of blood pumped by one ventricle with each heartbeat
a very large number of mitochondria in the cytoplasm
Which of the following factors gives the myocardium its high resistance to fatigue?
Unlike skeletal muscle cells, cardiac muscle cells can be autorhythmic.
Which of the following is a difference between cardiac muscle and skeletal muscle?
left and right ventricles
The interventricular septum forms a dividing wall between the __________.
ventricles
The trabeculae carneae are located in the __________.
right atrium and right ventricle
The tricuspid valve is located between the __________.
coronary arteries
The vessels that carry oxygen to the myocardium are called __________.
The heart is enclosed in a double-layered sac called the pleural membrane.
Which of the following statements is NOT true about the shape, position, and location of the heart?
the epicardium
Which of the following structures is superficial to the heart wall and serves to protect the heart, anchor the heart, and prevent the heart from overfilling?
the mitral, or bicuspid, valve
Which of the following valves is most often faulty in the heart?
parasympathetic stimulation
Which of the following would lead to a decrease in heart rate?
pulmonary semilunar valve
prevents backflow of blood into the right ventricle
posterior interventricular artery
runs to the apex of the heart