Cardiovascular System

Every question here, with the answer

1. A student is reviewing heart anatomy before listening to heart sounds. Which statement about the base of the heart is accurate?

   1. It is the superior surface of the heart, where the great veins and great arteries attach
   2. It is the middle layer of the heart, made of cardiac muscle cells
   3. It is the inferior tip of the heart
   4. It is the chamber that receives oxygenated blood from the lungs

   Answer: It is the superior surface of the heart, where the great veins and great arteries attach

   The great veins (superior and inferior venae cavae) and great arteries (aorta and pulmonary trunk) attach to the superior surface of the heart, called the base. The inferior tip is the apex, the muscle layer is the midlayer, and the left atrium receives oxygenated blood from the lungs.

2. A patient has fluid loss after exertion in hot weather. Which findings would the nurse recognize as consistent with hypovolemia and low perfusion? Select all that apply.

   1. Cool and clammy skin
   2. Low urine output
   3. Laboratory results illustrating a concentrated sample
   4. Warm, dry skin with increased vascular volume
   5. Mental status changes ranging from slight confusion to seizure

   Answer: Cool and clammy skin, Low urine output, Laboratory results illustrating a concentrated sample, Mental status changes ranging from slight confusion to seizure

   Hypovolemia means less fluid volume in the circulatory system and is associated with signs of low perfusion, including mental status changes, cool clammy skin, low urine output, and concentrated laboratory results. Increased vascular volume is more consistent with hypervolemia, not hypovolemia.

3. A patient’s heart rate is very fast. The nurse is concerned that cardiac output may not be maintained if the rate continues to increase. What is the best physiological explanation?

   1. The coronary arteries supply blood only during systole
   2. The ventricles may not have enough time for adequate filling, reducing stroke volume
   3. The systemic circuit stops returning deoxygenated blood to the heart
   4. The left atrium stops receiving oxygenated blood from the lungs

   Answer: The ventricles may not have enough time for adequate filling, reducing stroke volume

   When heart rate becomes too fast, stroke volume can decrease because ventricular filling time is insufficient. The section describes tachycardia as temporarily compensatory, but too rapid a rate can impair stroke volume.

4. A patient is experiencing sympathetic nervous system stimulation during acute stress. Which responses would the nurse expect based on cardiovascular regulation? Select all that apply.

   1. Bronchoconstriction with lower blood pressure
   2. Increased heart rate and blood pressure
   3. Bronchodilation
   4. Pupillary dilation
   5. Glucose release

   Answer: Increased heart rate and blood pressure, Bronchodilation, Pupillary dilation, Glucose release

   The sympathetic nervous system is associated with fight-or-flight responses such as bronchodilation, pupillary dilation, glucose release, and increased HR and BP. Bronchoconstriction and lower BP are listed as parasympathetic-associated responses.

5. A nurse is teaching a patient why valves in larger veins are important for circulation. Which explanation is most accurate?

   1. They help blood move toward the heart and prevent backflow
   2. They exchange nutrients and wastes at the cellular level
   3. They carry blood away from the heart under high pressure
   4. They provide the primary blood supply to cardiomyocytes

   Answer: They help blood move toward the heart and prevent backflow

   Larger veins have valves that support one-way movement of blood toward the heart and help prevent backflow, especially because veins are low-pressure vessels affected by gravity. Capillaries exchange nutrients and wastes, arteries carry blood away from the heart, and coronary arteries perfuse cardiomyocytes.

6. A nurse is reviewing an ECG rhythm strip and determining whether it meets criteria for normal sinus rhythm. Which criteria should the nurse use? Select all that apply.

   1. The rate is between 60 and 100 beats per minute
   2. The impulse begins at the SA node
   3. The rhythm is identified only by specialized testing used to obtain stroke volume
   4. The AV node initiates the impulse because the SA node does not fire
   5. The impulse travels from the SA node to the AV node in 0.12 seconds or less

   Answer: The rate is between 60 and 100 beats per minute, The impulse begins at the SA node, The impulse travels from the SA node to the AV node in 0.12 seconds or less

   Normal sinus rhythm requires that the impulse start in the SA node, travel to the AV node in 0.12 seconds or less, and have a rate of 60 to 100 beats per minute. AV-node initiation is a backup mechanism if the SA node does not fire, and stroke volume testing is unrelated to the criteria for normal sinus rhythm.