1.
Most of the middle layer in the heart wall is composed of
Correct Answer
A. Cardiac muscle cells.
Explanation
The correct answer is cardiac muscle cells. The middle layer of the heart wall, known as the myocardium, is primarily composed of cardiac muscle cells. These cells are specialized for contraction and play a crucial role in pumping blood throughout the body. Unlike other types of muscle cells, such as smooth muscle cells, cardiac muscle cells have distinct striations and are interconnected by intercalated discs, allowing for coordinated contractions. Therefore, cardiac muscle cells are the main component of the middle layer of the heart wall.
2.
Which of the following descriptions matches the term near the left fifth intercostal space?
Correct Answer
C. Apex of heart
Explanation
The term "near the left fifth intercostal space" refers to a specific location on the chest. The apex of the heart is located in this region, making it the correct answer. The pericardial cavity refers to the space surrounding the heart, the visceral pericardium is the inner layer of the pericardium, the aorta is a major blood vessel that carries oxygenated blood from the heart, and the right atrium is one of the chambers of the heart. However, none of these descriptions specifically match the location near the left fifth intercostal space.
3.
Intercalated discs serve to transfer ________ from cell to cell.
Correct Answer
D. All of the above
Explanation
Intercalated discs are specialized structures found in cardiac muscle cells. They contain gap junctions, which allow for the transfer of ionic currents and action potentials from cell to cell. These electrical signals are essential for coordinating the contraction of the heart muscle. Therefore, intercalated discs play a crucial role in transferring both ionic currents and action potentials, as well as facilitating the force of contraction in cardiac muscle cells. Hence, the correct answer is "all of the above".
4.
In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the
Correct Answer
C. Mediastinum.
Explanation
The correct answer is mediastinum. The question is asking for the region in the middle of the thoracic cavity that is occupied by various structures including the heart, great vessels, thymus, esophagus, and trachea. This region is known as the mediastinum. The other options, such as pleural space, pericardial space, cardiac notch, and ventral cavity, do not accurately describe this specific region in the thoracic cavity.
5.
The visceral pericardium is the same as the
Correct Answer
C. Epicardium.
Explanation
The visceral pericardium refers to the innermost layer of the pericardium, which is the protective sac surrounding the heart. It is also known as the epicardium. The epicardium is a thin layer of connective tissue that covers the outer surface of the heart and helps to protect and lubricate it. It is responsible for providing a smooth surface for the heart to beat against and helps to reduce friction between the heart and surrounding structures. Therefore, the correct answer is epicardium.
6.
The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as
Correct Answer
A. Cardiac tamponade.
Explanation
Cardiac tamponade refers to the accumulation of fluid in the pericardial cavity, which is the space between the heart and the pericardium (the sac surrounding the heart). This fluid buildup puts pressure on the heart, restricting its movement and affecting its ability to pump blood effectively. It can be a life-threatening condition requiring immediate medical intervention. Mitral valve prolapse, pleural effusion, cardiomyopathy, and pericarditis are all different conditions that do not specifically involve fluid accumulation in the pericardial cavity.
7.
The earlike extension of the atrium is the
Correct Answer
D. Auricle.
Explanation
The correct answer is "auricle." The earlike extension of the atrium is called the auricle. It is a small, muscular pouch that helps to increase the capacity of the atrium, allowing it to hold more blood. The auricle also helps to direct blood flow into the atrium and prevent backflow.
8.
The coronary sulcus is a groove that
Correct Answer
A. Marks the border between the atria and ventricles.
Explanation
The coronary sulcus is a groove that marks the border between the atria and ventricles. This groove is located on the surface of the heart and helps to separate the upper chambers (atria) from the lower chambers (ventricles). It serves as a landmark for identifying the different regions of the heart and is important for understanding the anatomy and function of the heart.
9.
There are ________ pulmonary veins.
Correct Answer
B. 4
Explanation
There are four pulmonary veins.
10.
The interventricular sulci and coronary sulcus contain
Correct Answer
D. All of the above
Explanation
The interventricular sulci and coronary sulcus contain fat, arteries, and veins. The interventricular sulci are grooves on the surface of the heart that separate the left and right ventricles. These sulci contain fat, which helps to protect and cushion the heart. The coronary sulcus is a groove that encircles the heart and contains the coronary arteries and veins, which supply blood to the heart muscle. Therefore, all of the given options, including fat, arteries, and veins, are present in the interventricular sulci and coronary sulcus.
11.
Blood is supplied to the myocardium by
Correct Answer
C. The coronary arteries.
Explanation
The correct answer is the coronary arteries. The myocardium, which is the muscular tissue of the heart, receives blood supply from the coronary arteries. These arteries branch off from the aorta and provide oxygenated blood to the heart muscle. The coronary arteries ensure that the myocardium receives the necessary nutrients and oxygen to function properly. The other options, such as the coronary sinus or contact with blood in the pumping chambers, are not correct as they do not supply blood to the myocardium.
12.
The first blood vessels to branch from the aorta are the ________ arteries.
Correct Answer
B. Coronary
Explanation
The first blood vessels to branch from the aorta are the coronary arteries. These arteries supply oxygenated blood to the heart muscle itself. They are responsible for delivering the necessary nutrients and oxygen to the heart, allowing it to function properly. Without the coronary arteries, the heart would not receive the blood supply it needs, which could lead to various heart conditions and complications.
13.
The marginal branch and posterior interventricular branch are branches of the
Correct Answer
A. Right coronary artery.
Explanation
The marginal branch and posterior interventricular branch are both branches of the right coronary artery. The right coronary artery is one of the main arteries that supplies blood to the heart muscle. The marginal branch runs along the right border of the heart and supplies blood to the right ventricle. The posterior interventricular branch runs along the back of the heart and supplies blood to the posterior part of the interventricular septum and the posterior walls of the ventricles. Therefore, the correct answer is the right coronary artery.
14.
The circumflex branch and the anterior interventricular artery are branches of the
Correct Answer
B. Left coronary artery.
Explanation
The circumflex branch and the anterior interventricular artery are both branches of the left coronary artery. The left coronary artery is responsible for supplying blood to the left side of the heart, including the left ventricle and left atrium. The circumflex branch wraps around the left side of the heart, while the anterior interventricular artery supplies blood to the front of the heart. Therefore, the left coronary artery is the correct answer as it gives rise to both of these important branches.
15.
The great and middle cardiac veins drain blood into the
Correct Answer
C. Coronary sinus.
Explanation
The great and middle cardiac veins are responsible for draining blood from the heart muscle. This blood is then collected into a large vein called the coronary sinus. The coronary sinus is located in the coronary sulcus, which is a groove that runs along the surface of the heart. From the coronary sinus, the blood is eventually returned to the right atrium of the heart. Therefore, the correct answer is coronary sinus.
16.
The ________ deliver(s) blood to the myocardium.
Correct Answer
E. Right coronary artery and left coronary artery
Explanation
The right coronary artery and left coronary artery are responsible for delivering blood to the myocardium, which is the muscular tissue of the heart. These arteries supply oxygen and nutrients to the heart muscle, ensuring its proper functioning.
17.
Blood is supplied to the left atrium by the
Correct Answer
C. Left coronary artery.
Explanation
The left coronary artery is responsible for supplying blood to the left atrium. It is one of the main branches of the aorta and plays a crucial role in providing oxygenated blood to the heart muscle. The left coronary artery divides into two main branches, the left anterior descending artery and the left circumflex artery, which supply blood to different areas of the heart. This ensures that the left atrium receives a sufficient blood supply for its proper functioning.
18.
Coronary veins empty into the
Correct Answer
C. Right atrium.
Explanation
Coronary veins empty into the right atrium. The coronary veins are responsible for draining deoxygenated blood from the heart muscle. After supplying oxygen and nutrients to the heart muscle, the coronary arteries collect the deoxygenated blood and transport it back to the right atrium through the coronary veins. From the right atrium, the blood will then be pumped into the right ventricle and eventually to the lungs for oxygenation. Therefore, the correct answer is right atrium.
19.
Blood returning to the heart from the systemic circuit first enters the
Correct Answer
A. Right atrium.
Explanation
Blood returning to the heart from the systemic circuit first enters the right atrium. This is because after oxygenated blood is delivered to the body through the systemic arteries, it returns to the heart through the systemic veins. The superior and inferior vena cava, which are large veins, carry deoxygenated blood from the body back to the heart. They both empty into the right atrium, where blood is then pumped into the right ventricle and eventually sent to the lungs for oxygenation. Therefore, the correct answer is right atrium.
20.
Blood returning to the heart from the pulmonary circuit first enters the
Correct Answer
C. Left atrium.
Explanation
Blood returning to the heart from the pulmonary circuit first enters the left atrium. This is because after oxygenation in the lungs, the oxygen-rich blood is transported back to the heart through the pulmonary veins, which empty into the left atrium. From the left atrium, the blood then passes through the mitral valve into the left ventricle before being pumped out to the rest of the body.
21.
The atrioventricular valves permit blood flow
Correct Answer
A. In one direction only.
Explanation
The atrioventricular valves are located between the atria and ventricles of the heart. Their main function is to prevent the backflow of blood from the ventricles back into the atria during ventricular contraction. This ensures that blood flows in one direction only, from the atria to the ventricles.
22.
Blood leaves the right ventricle by passing through the
Correct Answer
B. Pulmonary valve.
Explanation
The pulmonary valve is the correct answer because it is responsible for allowing blood to leave the right ventricle and enter the pulmonary artery, which carries deoxygenated blood to the lungs for oxygenation. The other options mentioned are incorrect as they are not directly involved in the passage of blood from the right ventricle.
23.
The cusps (leaflets) of atrioventricular valves attach directly to
Correct Answer
C. Chordae tendineae.
Explanation
The cusps (leaflets) of atrioventricular valves attach directly to chordae tendineae. Chordae tendineae are strong, fibrous cords that connect the cusps of the atrioventricular valves to the papillary muscles in the ventricles. This connection helps to prevent the valves from inverting or prolapsing during ventricular contraction, ensuring proper blood flow through the heart.
24.
The right ventricle pumps blood to the
Correct Answer
A. Right and left lungs.
Explanation
The right ventricle pumps blood to both the right and left lungs. This is because the right ventricle receives deoxygenated blood from the right atrium and pumps it to the lungs through the pulmonary artery. In the lungs, the blood picks up oxygen and gets rid of carbon dioxide before returning to the heart. Therefore, the right ventricle is responsible for pumping blood to both lungs.
25.
The left ventricle pumps blood to the
Correct Answer
D. Aorta.
Explanation
The left ventricle is responsible for pumping oxygenated blood from the heart to the rest of the body through the aorta, the largest artery in the body. The aorta carries the oxygenated blood to all the organs and tissues, ensuring that they receive the necessary oxygen and nutrients for proper functioning.
26.
The right atrium receives blood from the
Correct Answer
D. All of the above
Explanation
The right atrium receives blood from all of the above sources, including the coronary sinus, superior vena cava, and inferior vena cava. The coronary sinus drains deoxygenated blood from the heart muscle, while the superior vena cava brings deoxygenated blood from the upper body, and the inferior vena cava brings deoxygenated blood from the lower body.
27.
Blood flowing into the heart from the venae cavae flows next through the ________ valve.
Correct Answer
C. Tricuspid
Explanation
The blood flowing into the heart from the venae cavae flows next through the tricuspid valve.
28.
As blood leaves the right ventricle it passes through the ________ and then into the pulmonary trunk.
Correct Answer
B. Pulmonary valve
Explanation
As blood leaves the right ventricle, it passes through the pulmonary valve. The pulmonary valve is located between the right ventricle and the pulmonary trunk. Its main function is to prevent the backflow of blood from the pulmonary trunk into the right ventricle. This allows the blood to flow in one direction, from the heart to the lungs, where it can be oxygenated.
29.
The function of the atrium is to
Correct Answer
E. Collect blood and pump blood to the ventricle.
Explanation
The atrium has two main functions: to collect blood and to pump blood to the ventricle. It receives blood from the veins and acts as a holding chamber, allowing blood to flow into the ventricle when it contracts. Therefore, the correct answer is that the atrium collects blood and pumps it to the ventricle.
30.
Compared to the right ventricle, the left ventricle has all the following characteristics, except that it
Correct Answer
C. Pumps a greater volume.
Explanation
The left ventricle has a thicker wall, is round in cross section, contracts harder, and produces about four to six times more pressure when it contracts compared to the right ventricle. However, it does not pump a greater volume.
31.
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?
Correct Answer
C. 5, 1, 3, 7, 8, 2, 4, 6
32.
The pulmonary arteries carry blood to the
Correct Answer
B. Lungs.
Explanation
The correct answer is "lungs" because the pulmonary arteries are responsible for carrying deoxygenated blood from the heart to the lungs, where it can receive oxygen and get rid of carbon dioxide. This oxygenated blood is then returned to the heart to be pumped to the rest of the body.
33.
The pulmonary veins carry blood to the
Correct Answer
A. Heart.
Explanation
The pulmonary veins carry blood to the heart. This is because the pulmonary veins are responsible for transporting oxygenated blood from the lungs back to the heart so that it can be pumped to the rest of the body. The heart then distributes this oxygenated blood to the various organs and tissues, allowing them to receive the necessary oxygen and nutrients for proper functioning.
34.
Use Figure 18-1 to answer the following questions:
34) Identify the structure labeled "19."
Correct Answer
B. Pulmonary semilunar valves
Explanation
The structure labeled "19" in Figure 18-1 is the pulmonary semilunar valves.
35.
Use Figure 18-1 to answer the following questions:
Identify the structure labeled "8."
Correct Answer
C. Papillary muscles
Explanation
The structure labeled "8." in Figure 18-1 is the papillary muscles.
36.
Use Figure 18-1 to answer the following questions:
Identify the structure labeled "6."
Correct Answer
A. Cusp of tricuspid valve
Explanation
The structure labeled "6." in Figure 18-1 is the cusp of the tricuspid valve.
37.
Use Figure 18-1 to answer the following questions:
Identify the structure labeled "21."
Correct Answer
D. Ligamentum arteriosum
Explanation
The structure labeled "21" in Figure 18-1 is the ligamentum arteriosum.
38.
Use Figure 18-1 to answer the following questions:
Which chamber receives oxygenated blood from the pulmonary circuit?
Correct Answer
C. 16
Explanation
Chamber 16 receives oxygenated blood from the pulmonary circuit.
39.
The foramen ovale in the fetal heart is located in the
Correct Answer
E. Interatrial septum.
Explanation
The foramen ovale is a small opening in the interatrial septum, which is the wall that separates the right and left atria of the heart. This opening allows blood to bypass the fetal lungs and flow directly from the right atrium to the left atrium. This is important during fetal development because the lungs are not yet functioning and the oxygenation of blood occurs through the placenta. After birth, the foramen ovale typically closes, redirecting blood flow through the lungs.
40.
The wall of the left ventricle is thicker than the right because
Correct Answer
D. All of the above
Explanation
The wall of the left ventricle is thicker than the right because the left ventricle does more work than the right ventricle. This is because the left ventricle pumps blood to the entire body, while the right ventricle only pumps blood to the lungs. Additionally, the left ventricle pumps against greater resistance than the right ventricle, as the systemic circulation has a higher resistance compared to the pulmonary circulation. Lastly, the left ventricle produces a higher pressure than the right ventricle to overcome the greater resistance and pump blood effectively throughout the body.
41.
The ________ ventricle has a greater workload than the ________.
Correct Answer
A. Left; right ventricle
Explanation
The left ventricle has a greater workload than the right ventricle. This is because the left ventricle is responsible for pumping oxygenated blood to the rest of the body through the systemic circulation, which requires more force. The right ventricle, on the other hand, pumps deoxygenated blood to the lungs for oxygenation, which requires less force. Therefore, the left ventricle has a higher workload compared to the right ventricle.
42.
Contractions of the papillary muscles
Correct Answer
D. Prevent the atrioventricular valves from reversing into the atria.
Explanation
The contractions of the papillary muscles prevent the atrioventricular valves from reversing into the atria. These muscles are located in the ventricles of the heart and are connected to the atrioventricular valves by chordae tendineae. When the ventricles contract, the papillary muscles also contract, pulling on the chordae tendineae and preventing the valves from flipping back into the atria. This ensures that blood flows in one direction, from the atria to the ventricles, and prevents any backflow of blood into the atria.
43.
The pulmonary semilunar valve prevents backward flow into the
Correct Answer
D. Right ventricle.
Explanation
The pulmonary semilunar valve is located between the right ventricle and the pulmonary trunk. Its main function is to prevent the backward flow of blood from the pulmonary trunk into the right ventricle. This ensures that oxygenated blood from the lungs is directed towards the systemic circulation through the aorta, rather than returning to the right ventricle. Therefore, the correct answer is right ventricle.
44.
The bicuspid or mitral valve is located
Correct Answer
E. Between the left atrium and left ventricle.
Explanation
The bicuspid or mitral valve is located between the left atrium and left ventricle. This valve prevents the backflow of blood from the left ventricle to the left atrium during the contraction of the heart. It consists of two leaflets or cusps, which open and close to regulate the flow of blood. The location of the bicuspid valve between the left atrium and left ventricle ensures that oxygenated blood is pumped out of the left ventricle and into the systemic circulation, while preventing any backflow into the atrium.
45.
The ________ valve prevents backward flow into the left atrium.
Correct Answer
C. Bicuspid
Explanation
The bicuspid valve, also known as the mitral valve, is located between the left atrium and the left ventricle of the heart. Its main function is to prevent the backward flow of blood from the left ventricle into the left atrium during ventricular contraction.
46.
Rupture of the papillary muscles in the left ventricle may result in
Correct Answer
E. All of the above
Explanation
The rupture of the papillary muscles in the left ventricle can lead to several complications, including mitral regurgitation, mitral valve prolapse, and bicuspid regurgitation. This is because the papillary muscles are responsible for anchoring the mitral and bicuspid valves, and their rupture can cause the valves to malfunction. Therefore, all of the options provided can be potential consequences of papillary muscle rupture in the left ventricle.
47.
When the semilunar valves close, the AV valves then
Correct Answer
B. Open.
Explanation
When the semilunar valves close, it indicates the end of ventricular systole and the beginning of ventricular diastole. During this phase, the atria fill with blood and the pressure inside the ventricles decreases. As a result, the AV valves open, allowing blood to flow from the atria into the ventricles. Therefore, the correct answer is "open."
48.
If a patient's tricuspid valve was leaking during systole, what would happen?
Correct Answer
C. Regurgitation into the left atrium
Explanation
If a patient's tricuspid valve was leaking during systole, regurgitation into the left atrium would occur. The tricuspid valve is located between the right atrium and right ventricle, so if it is leaking, blood would flow back into the right atrium. However, since the left and right atria are connected, the regurgitated blood from the right atrium can also flow into the left atrium. This would result in regurgitation into the left atrium.
49.
David suffers from a prolapsed mitral valve. This condition would cause
Correct Answer
E. Increased effort by the left ventricle and regurgitation.
Explanation
A prolapsed mitral valve refers to the improper closure of the valve between the left atrium and the left ventricle of the heart. This condition would cause regurgitation, which means that blood would flow backward into the left atrium instead of moving forward into the aorta. As a result, the left ventricle would need to exert increased effort to pump blood out of the heart and into the circulation. Therefore, the correct answer is increased effort by the left ventricle and regurgitation.
50.
Complications related to arteriosclerosis account for roughly ________ percent of deaths in the United States.
Correct Answer
D. 50
Explanation
Arteriosclerosis is a condition characterized by the hardening and narrowing of arteries, which can lead to various complications such as heart attacks and strokes. The given answer of 50 percent suggests that half of the deaths in the United States are caused by complications related to arteriosclerosis. This indicates the significant impact of this condition on mortality rates in the country.