Heart Anatomy and Physiology Worksheet

Which of the following correctly describes the mediastinum?

• It is a cavity within the right lung that contains the heart.

• It is the space between the lungs extending from the sternum to the vertebral column.

• It is a layer of the pericardium that attaches the heart to the diaphragm.

• It is a structure separating the atria and ventricles of the heart.

Which layer is both a part of the pericardium and a part of the heart wall?

• Parietal layer of the serous pericardium

• Fibrous pericardium

• Visceral layer of the serous pericardium (epicardium)

• Myocardium

Why is the myocardium of the left ventricle significantly thicker than that of the right ventricle?

• It pumps blood through a smaller circuit under higher resistance.

• It pumps blood a shorter distance to the lungs.

• It functions as the pacemaker of the heart.

• It contains more chordae tendineae than the right ventricle.

Which of the following is not a function of the fibrous skeleton of the heart?

• Prevents overstretching of heart valves

• Electrically insulates the atria from ventricles

• Serves as an attachment for cardiac muscle fibers

• Directly generates the heartbeat

Papillary muscles prevent atrioventricular valve cusps from:

• Opening during ventricular relaxation

• Everting into the atria during ventricular contraction

• Closing during atrial contraction

• Collapsing during diastole

Which coronary blood vessel delivers oxygenated blood to the walls of the left atrium and left ventricle?

• Right coronary artery

• Anterior interventricular branch

• Circumflex branch of the left coronary artery

• Posterior interventricular branch

In chronic pericarditis, accumulation of excessive pericardial fluid may result in:

• Myocardial ischemia

• Cardiac tamponade

• Atrial septal defect

• Coronary embolism

Which component of the cardiac conduction system is the only electrical connection between the atria and ventricles?

• Atrioventricular (AV) bundle

• Sinoatrial (SA) node

• Purkinje fibers

• Atrioventricular (AV) node

Why can tetanus (sustained contraction) not occur in cardiac muscle?

• Cardiac fibers lack calcium channels.

• Cardiac fibers have a long refractory period that lasts longer than contraction.

• The plateau phase prevents repolarization.

• The heart depends only on anaerobic ATP production.

An enlarged Q wave in an electrocardiogram typically indicates:

• Atrial fibrillation

• Myocardial infarction

• Ventricular hypertrophy

• Coronary artery spasm