Heart and Cardiovascular Exam
At a heartbeat of 60 beats/ minute, a cardiac cycle lasts
1 second
Why can cardiac tamponade be a life-threatening condition? (Module 18.2C)
Cardiac tamponade can be life-threatening because accumulating fluid in the pericardial cavity restricts heart movement
Which structure collects blood from the myocardium and into which heart chamber does this blood flow?
Coronary veins collect blood from the myocardium and carry it to the right atrium
Describe what happens to blood flow during elastic rebound. (Module 18.5D)
Elastic rebound is when blood in the aorta is driven forward into the systemic circuit, some is forced back toward the left ventricle and into the coronary arteries
Depolarization of the atria corresponds to the ECG's
P wave
If a patient's tricuspid valve was leaking during systole, what would happen?
Regurgitation back into the right atrium
Compare the anterior cardiac veins to the posterior vein of the left ventricle. (Module 18.5B)
The anterior cardiac veins drain the anterior surface of the right ventricle and empty into the right atrium; the posterior vein of left ventricle drains the area supplied by the circumflex artery (posterior surface of the left ventricle)
Compare the base of the heart with the apex. (Module 18.1B)
The base of the heart is the superior portion where the largest veins and arteries are attached. The apex of the heart is located on the inferior aspect of the heart
Complications related to arteriosclerosis account for roughly ________ percent of deaths in the United States
50
Describe the areas of the heart supplied by the right and left coronary arteries. (Module 18.5A)
The right coronary artery supplies blood to the right atrium, portions of both ventricles, and the conducting system. The left coronary artery supplies blood to the left ventricle, left atrium, and interventricular septum
The ________ lines the chambers of the heart, covers the heart valves, and is continuous with the endothelium
endocardium
The ________ separate(s) the two ventricles
interventricular septum
What occurs at the circled label "4" on the graph?
isovolumetric contraction
The circumflex branch and the anterior interventricular artery are branches of the
left coronary artery
The coronary sulcus is a groove that
marks the border between the atria and ventricles
From superficial to deep, name the layers of the heart wall. (Module 18.3A)
pericardium, myocardium, endocardium
The volume of blood ejected from each ventricle during a contraction is called the
stroke volume
Which of the following is greater during left ventricular systole?
the peak pressure in the ventricle
The cavity that contains the lungs, the heart, great vessels, thymus, esophagus, and trachea is called the
thoracic cavity
Blood flowing into the heart from the venae cavae flows next through the ________ valve
tricuspid
The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the
ventricular ejection of ventricular systole
The heart pumps approximately ________ milliliters of blood each minute
6,000
What do semilunar valves prevent?
Semilunar valves prevent backflow of blood into the ventricles
If the connection between the SA node and AV node becomes blocked,
the ventricles will beat more slowly
List the phases of the cardiac cycle. (Module 18.10A)
atrial systole, atrial diastole, ventricular systole, ventricular diastole
The heart is innervated by ________ nerves
both parasympathetic and sympathetic
Blood returning to the heart from the pulmonary circuit first enters the
left atrium
Heart rate is controlled by neurons of the cardiovascular center located in the
medulla oblongata
During the T wave of the electrocardiogram, the ventricles are electrically ________ and functionally ________
repolarizing; relaxing
The marginal branch and posterior interventricular branch are branches of the
right coronary artery
The _________ delivers blood to the myocardium
right coronary artery and left coronary artery
The pulmonary semilunar valve prevents backward flow into the
right ventricle
What occurs at "B" on the graph?
semilunar valve closes
Tetanic muscle contractions don't occur in a normal cardiac muscle because
the refractory period lasts until the muscle relaxes
There are __________ pulmonary veins
4
Pacemaker cells isolated from the SA node generate action potentials at ______ beats per minute
80-100
Compute Joe's stroke volume if his end-systolic volume (ESV) is 40 mL and his end-diastolic volume (EDV) is 125 mL
85 mL
Define cardiac regurgitation. (Module 18.7A)
Cardiac regurgitation is the backflow of blood into the atria when the ventricles contract
In cardiac muscle, the fast depolarization phase of the action potential is the result of ________ membrane permeability to ________ ions
increased; sodium
The left border of the heart is formed by the
left atrium and left ventricle
Describe the sites and actions of the cardioinhibitory and cardioacceleratory centers
The cardioacceleratory center in the medulla oblongata activates sympathetic neurons to increase heart rate; the cardioinhibitory center in the medulla oblongata activates parasympathetic neurons that slow heart rate
Name the four chambers of the heart. (Module 18.1C)
left atrium, left ventricle, right atrium, right ventricle
Most of the mass of the heart lies to the _______ the midline
left of
The entire space between the pleural cavities containing only the heart, great vessels, thymus, trachea and esophagus is called the
mediastinum
The muscle layer of the heart is the
myocardium
The interventricular sulci and coronary sulci contain all of the following except
nerves
If the cells of the SA node failed to function, how would the heart rate be affected? (Module 18.12B)
The heart would beat slower because the AV node would be the pacemaker
Define mediastinum. (Module 18.2A)
The mediastinum is the region between the two pleural cavities that contains the heart, along with the great vessels, thymus, esophagus, and trachea
The cusps (leaflets) of atrioventricular valves attach directly to
chordae tendineae
The first heart sound ("lubb") is associated with
closing of the mitral valve
When the left ventricle contracts, the diameter of the ventricular chamber
decreases
The ________ is the amount of blood in a ventricle after it has contracted and before it begins to refill
end-systolic volume
In cardiac muscle, calcium ions
enter the cell through slow ion channels
The pulmonary veins carry blood to the
heart
The heart beats approximately ________ times each day.
100,000
Compute Joe's stroke volume if his end-systolic volume (ESV) is 40 mL and his end-diastolic volume (EDV) is 125 mL. (Module 18.16B)
85 mL
Define electrocardiogram. (Module 18.13A)
An electrocardiogram is a recording of the electrical activity of the heart
Compare the duration of atrial and ventricular systole at a representative heart rate of 75 bpm. (Module 18.9C)
Atrial systole has a duration of 100 msec, and ventricular systole has a duration of 270 msec
Which parts of the following statement are true? The AV node delivers the stimulus to the AV bundle, located within the interventricular septum.
Both parts are true
Which parts of the following statement are true? The cardioacceleratory center activates sympathetic neurons and the cardioinhibitory center controls parasympathetic neurons.
Both parts are true
Describe the location and position of the heart. (Module 18.1A)
The heart is located near the anterior chest wall, directly behind the sternum
Describe the hearts location in the body. (Module 18.2 B)
The heart is surrounded by the pericardium in the anterior mediastinum, deep to the sternum, and superior to the diaphram
The left ventricle pumps blood to the
aorta
The ________ valve opens when left ventricular pressure exceeds aortic blood pressure
aortic
What occurs at A on the graph? Figure 18-2
aortic semilunar valve opens
The earlike extension of the atrium is the
auricle
What do semilunar valves prevent?
back flow of blood into the ventricles
The superior portion of the heart where major blood vessels enter and exit is the
base
The bicuspid, or mitral, valve is located
between the left atrium and left ventricle
Most of the middle layer in the heart wall is composed of
cardiac muscle cells
The function of the atrium is to
collect blood and pump blood to the ventricle
The first blood vessels to branch from the aorta are the ________ arteries.
coronary
The great and middle cardiac veins drain blood into the
coronary sinus
Drugs that block the beta-one adrenergic receptors will
decrease heart rate
Drugs known as calcium channel blockers such as nifedipine can be used to
decrease the force of cardiac contraction
The ________ is the volume of blood in a ventricle at the beginning of systole
end-diastolic volume
Caffeine has effects on conducting cells and contractile cells that are similar to those of NE. What effect would drinking large amounts of caffeinated beverages have on the heart rate? (Module 18.14C)
heart rate would increase
Contractions of the papillary muscles
prevent the atrioventricular valves from reversing into the atria
As blood leaves the right ventricle it passes through the ________ and then into the pulmonary trunk
pulmonary valve
Blood leaves the right ventricle by passing through the
pulmonary valve
The right atrium receives blood from all of the following except the
pulmonary veins
There are _____ pulmonary veins
4
The following are structural components of the conducting system of the heart. 1. Purkinje fibers 2. AV bundle 3. AV node 4. SA node 5. bundle branches The sequence in which excitation would move through this system is which of the following?
4, 3, 2, 5, 1
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. venae cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins What is the correct order for the flow of blood entering from the systemic circulation?
5, 1, 3, 7, 8, 2, 4, 6
Why is it important that cardiac tissue contain many mitochondria and capillaries? (Module 18.3C)
Cardiac tissue is metabolically active and dependent on mitochondrial activity to use aerobic respiration to generate ATP and capillaries provide the oxygen and nutrients for this process
What is coronary ischemia? (Module 18.8B)
Coronary ischemia is a condition in which the blood supply of the coronary arteries is reduced
If there is a complete block between the SA node and the AV node, how would the ECG be affected?
The rate of P waves will be faster than the rate
Define heart failure. (Module 18.16A)
Heart failure is a condition where the heart can no longer meet the oxygen and nutrient demands of peripheral tissues
The P wave of the electrocardiogram is a signal from
depolarization of the atria
Arteriosclerosis can lead to all of the following except
diabetes
The visceral pericardium is the same as the
epicardium
The atrioventricular valves permit blood flow
in one direction only
Each of the following factors will increase cardiac output except
increased parasympathetic stimulation
Which of the following would decrease heart rate?
increased parasympathetic stimulation of nodal fibers
The wall(s) of the ________ rest(s) on the diaphragm
right ventricle
As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit
tetany
Blood is supplied to the myocardium by
the coronary arteries
Which of the following would be greater?
the end-diastolic volume when the heart rate is 60 beats/minute
Muscular ridges on the inner surface of the ventricles are called
trabeculae carneae
The long plateau phase of the cardiac muscle action potential is due to
voltage-gated calcium channels remaining open
What effect would an increase in venous return have on the stroke volume?
An increase in venous return would fill the ventricles with more blood, increasing sarcomere length, which would increase the stroke volume
Compare the duration of atrial and ventricular systole at a representative heart rate of 75 bpm
Atrial systole has a duration of 100 msec, and ventricular systole has a duration of 270 msec
Compare the volume of blood each circuit receives from contraction of the ventricles
Both circuits receive the same volume of blood
If the pacemaker cells in the SA node become more permeable to potassium ions,
Both heart rate will decrease, and membrane will hyperpolarize
Compare bradycardia with tachycardia. (Module 18.14A)
Bradycardia is a heart rate below 60 beats per minute and tachycardia is a heart rate above 100 beats per minute
Which structures collect blood from the myocardium, and into which heart chamber does this blood flow? (Module 18.4B)
Coronary veins collect blood from the myocardium and carry it to the right atrium
David suffers from a prolapsed mitral valve. This condition would cause
Increased effort by the left ventricle and regurgitation
What are the two phases of ventricular systole?
Isovolumetric contraction and ventricular ejection
The _________ has a greater workload than the _______
Left ventricle; right ventricle
What does the circle label "5" indicated on the graph?
Peak systolic pressure
Why does tetany not occur in cardiac muscle? (Module 18.11A)
Tetany does not occur because cardiac muscle has a long refractory period that continues until relaxation is well under way so summation cannot occur, and thus tetany cannot occur
Why is ventricular fibrillation fatal?
Ventricular fibrillation is fatal because the ventricles quiver and do not pump blood to the systemic circulation
An equivalent term for epicardium is
Visceral pericardium
Intercalated discs serve to transfer all of the following from cell to cell except
Z-lines
Cardiac output is increased by
all of the answers are correct
The inferior point of the heart is called the
apex
Which of the following descriptions matches the phrase "near the left fifth intercostal space"?
apex of heart
The contraction phase of the upper chambers of the heart is called
atrial systole
List the phases of the cardiac cycle
atrial systole, atrial diastole, ventricular systole, ventricular diastole
Activation of which kind of receptor causes heart rate to increase?
beta-one receptor
The ________ valve prevents backward flow into the left atrium
bicuspid
When the semilunar valves close, the AV valves then
open
Acetylcholine slows the heart because it
opens potassium ion channels in SA node cells and causes the pacemaker potential to depolarize more slowly
The cavity that contains only the heart is the
pericardial cavity
Damage to the semilunar valve on the right side of the heart would affect blood flow to which vessel? (Module 18.6B)
pulmonary trunk
Blood returning to the heart from the systemic circuit first enters the
right atrium
Coronary veins empty into the
right atrium
The ________ deliver(s) blood to the myocardium
right coronary artery and left coronary artery