A&P Chapter 18 Study Questions
The inferior vena cava brings blood from the lower regions of the body and empties into the __________.
Right atrium
The tricuspid valve is located between the __________.
Right atrium and right ventricle
From the perspective of blood returning from the systemic circuit, what is the correct sequence of blood flow through the chambers of the heart?
Right atrium, right ventricle, lungs, left atrium, left ventricle
During pulmonary circulation, blood leaves the __________ and flows to the __________.
Right ventricle and flows directly to the lungs
Where does the posterior interventricular artery run?
Runs to the apex of the heart
The normal pacemaker of the heart is the __________.
SA node
What is the correct sequence of electrical current flow through the heart wall?
SA node, AV node, AV bundle, right and left bundle branches, subendocardial conducting network
The trabeculae carneae are located in the __________.
Ventricles
Which factor gives the myocardium its high resistance to fatigue?
A very large number of mitochondria in the cytoplasm
An enlarged R wave on an ECG would indicate __________.
An enlarged ventricle
The coronary arteries arise from the __________.
Aorta
The superior chambers of the heart are called the __________.
Atria
The P wave of an electrocardiogram represents __________.
Atrial depolarization
The __________ are attached to the AV valve flaps.
Chordae tendineae
The second heart sound (the "dup" of "lub-dup") is caused by the __________.
Closure of the semilunar valves
Systole causes ______.
Contraction
The vessels that carry oxygen to the myocardium are called __________.
Coronary arteries
When the mitral valve closes, it prevents the backflow of blood from the __________.
Left ventricle into the left atrium
The lining of the heart chambers is called the __________.
Endocardium
What is the correct sequence of layers in the heart wall, starting with the outer layer?
Epicardium, myocardium, endocardium
The contractile cardiac muscle fibers of the myocardium behave as a single, coordinated unit called a __________.
Functional syncytium
A doctor puts his stethoscope on a patient's chest over the location of the heart and hears an abnormal swishing sound. What condition is the best diagnosis for the patient's condition?
Incompetent cardiac valve
What are the functions of the fibrous pericardium?
It prevents the heart from overfilling with blood, , protects the heart, and anchors the heart to surrounding structures
The interventricular septum forms a dividing wall between the __________.
Left and right ventricles
Into which chamber of the heart do the pulmonary veins deliver blood?
Left atrium
Freshly oxygenated blood is delivered to the __________, and then it passes into the __________ to be pumped to the body tissues (systemic circuit).
Left atrium; left ventricle
The most muscular chamber of the heart is the __________.
Left ventricle
During systemic circulation, blood leaves the __________.
Left ventricle and flows directly to the aorta
Guided by powerful signaling molecules, the human heart develops from __________.
Mesoderm
The noncontractile cardiac muscle cells that initiate their own depolarization and cause depolarization of the rest of the heart are called __________.
Pacemaker cells
What would lead to a decrease in heart rate?
Parasympathetic stimulation
The structure just deep to the fibrous pericardium is the __________.
Parietal layer of the serous pericardium
What is the function of the aortic semilunar valve?
Prevents backflow of blood into the left ventricle
What is the function of the pulmonary semilunar valve?
Prevents backflow of blood into the right ventricle
Diastole causes _______.
Relaxation
The role of the atrioventricular node (AV node) is to __________.
Slow down impulses so that the atria can contract to fill the adjacent ventricles with blood
The endocardium is composed of __________.
Squamous epithelium
What is the function of the anterior interventricular artery?
Supplies blood to the interventricular septum and anterior walls of both ventricles
What is the function of the right marginal artery?
Supplies blood to the lateral right side of the myocardium
What is the function of the circumflex artery?
Supplies blood to the left atrium and posterior walls of the left ventricle
What is cardiac output?
The amount of blood pumped by each ventricle in one minute
Cardiac output is __________.
The amount of blood pumped out of each ventricle in one minute
Which structure is superficial to the heart wall and serves to protect the heart, anchor the heart, and prevent the heart from overfilling?
The epicardium
What is the cardiac cycle?
The events associated with blood flow through the heart during one complete heartbeat
What part of the heart is considered the systemic circuit pump?
The left ventricle
Which valve is most often faulty in the heart?
The mitral, or bicuspid, valve
The absolute refractory period refers to the time during which __________.
The muscle cell will not respond to a stimulus of any strength
The cardiac cycle includes which events?
The number of times the heart beats in one minute
What is stroke volume?
The volume of blood pumped by one ventricle with each heartbeat
True or false. In the fetus, blood from the left and right sides of the heart normally mix.
True
What is a difference between cardiac muscle and skeletal muscle?
Unlike skeletal muscle cells, cardiac muscle cells can be autorhythmic.
The __________ nerve carries parasympathetic fibers to the sinoatrial (SA) node.
Vagus
Where is the mitral (bicuspid) valve located?
Valve between the left atrium and left ventricle
Where is the tricuspid valve located?
Valve between the right atrium and right ventricle