Paramedic Cardiology

• 
  Which of the following is the innermost layer of the heart?

• Epicardium

• Myocardium

• Endocardium

• Pericardium

Answer explanation

The innermost layer of the heart is the Endocardium, which lines the chambers and valves of the heart.

• 
  The myocardium is primarily composed of:

• Connective tissue

• Cardiac muscle tissue

• Endothelial cells

• Adipose tissue

Answer explanation

The myocardium is primarily composed of cardiac muscle tissue, which is responsible for the contraction of the heart and pumping of blood throughout the body.

• 
  Which layer of the heart is responsible for pumping blood?

• Epicardium

• Myocardium

• Endocardium

• Pericardium

Answer explanation

The correct layer responsible for pumping blood in the heart is the Myocardium.

Which choice below correctly identifies the layers of the heart from the most outer layer to the most inner layer?

• epicardium, myocardium, endocardium

• endocardium, myocardium, epicardium

• myocardium, endocardium, epicardium

• myocardium, epicardium, endocardium

Answer explanation

The correct choice is epicardium, myocardium, endocardium because it identifies the layers of the heart from the most outer layer to the most inner layer.

What prevents the backflow of blood during ventricular contraction

• The aortic valve

• 
  Semilunar valve

• The pulmonic valve

• Atrioventricular valve

Answer explanation

The atrioventricular valve prevents the backflow of blood during ventricular contraction.

• 
  Which chamber of the heart receives oxygenated blood from the lungs?

• Right atrium

• Left atrium

• Right ventricle

• Left ventricle

Answer explanation

The left atrium receives oxygenated blood from the lungs before it is pumped to the rest of the body.

• 
  What is the function of the sinoatrial (SA) node in the heart?

• To pump blood to the lungs

• To act as the heart's natural pacemaker

• To receive deoxygenated blood

• To separate the atria from the ventricles

Answer explanation

The function of the sinoatrial (SA) node in the heart is to act as the heart's natural pacemaker.

• 
  Which blood vessels carry blood away from the heart?

• Veins

• Arteries

• Capillaries

• Venules

Answer explanation

Arteries carry blood away from the heart, while veins carry blood back to the heart. Capillaries are tiny blood vessels where exchange of nutrients and waste occurs. Venules are small veins that connect capillaries to larger veins.

Which of the following statements regarding the right side of the heart is most correct

• .

  It receives blood exclusively from the venae cavae

• The right side of the heart is a low pressure pump

• It pumps against the high resistance of the pulmonary circulation

• 
  The right side of the heart pumps blood through the pulmonary veins

Answer explanation

The right side of the heart is a low pressure pump because it receives deoxygenated blood from the body through the venae cava and pumps it to the lungs for oxygenation. This is in contrast to the left side of the heart, which is a high pressure pump that receives oxygenated blood from the lungs and pumps it to the rest of the body. The right side of the heart has thinner walls and less muscle mass compared to the left side, allowing it to pump blood at a lower pressure

In contrast to the right side of the heart, the left side of the heart

• Drives blood out of the heart against the relatively high resistance of the systemic circulation

• 
  Is a high-pressure pump that sends blood through the pulmonary circulation and to the lungs

• Is a relatively low pressure pump that must stretcher its walls in order to force blood through the aorta

• Drives blood out of the heart against the relatively low resistance of the pulmonary circulation

Answer explanation

The left side of the heart drives blood out of the heart against the relatively high resistance of the systemic circulation. This means that the left side of the heart pumps oxygenated blood to the rest of the body, which requires more force due to the resistance in the blood vessels throughout the body. In contrast, the right side of the heart pumps deoxygenated blood to the lungs, which has a lower resistance in the pulmonary circulation.