Heart Structure and Function Quiz

Heart Structure and Function

• The heart comprises four chambers: two atria (receiving chambers) and two ventricles (pumping chambers).
• The heart is enclosed by the pericardium, a sac-like structure. The pericardium is composed of layers: epicardium (outer layer), myocardium (muscular middle layer), and endocardium (inner layer lining the chambers).
• The heart has four valves: two atrioventricular (AV) valves (tricuspid and mitral/bicuspid) and two semilunar valves (pulmonary and aortic).
• Chordae tendineae attach to the AV valve cusps preventing backflow of blood into the atria during ventricular contraction.
• Papillary muscles anchor the chordae tendineae, to aid in preventing valve inversion.

Blood Flow Through the Heart

• Deoxygenated blood enters the right atrium via the superior and inferior vena cava.
• Blood flows through the tricuspid valve to the right ventricle.
• The right ventricle pumps blood through the pulmonary valve to the pulmonary artery.
• The pulmonary artery carries blood to the lungs for oxygenation.
• Oxygenated blood returns to the left atrium via the pulmonary veins.
• Blood flows through the mitral valve to the left ventricle.
• The left ventricle pumps blood through the aortic valve to the aorta.
• The aorta distributes oxygenated blood throughout the body.

Circulation

• Pulmonary circulation: the pathway of blood between the heart and lungs.
• Systemic circulation: the pathway of blood between the heart and the rest of the body.
• Oxygenated blood is carried in arteries away from the heart.
• Deoxygenated blood is carried in veins toward the heart.

Heart's Conduction System

• The sinoatrial (SA) node is the natural pacemaker of the heart.
• The conduction system coordinates the heart's contractions (heartbeat): SA node → AV node → bundle of His → bundle branches → Purkinje fibers.

Blood Vessels

• Arteries carry blood away from the heart; veins carry blood toward the heart.
• Capillaries facilitate the exchange of gases (oxygen and carbon dioxide) and nutrients between blood and tissues.
• The largest artery is the aorta; the largest veins are the superior and inferior vena cava.

Heart Sounds (Lub-Dub)

• The "lub" sound is caused by the closure of the AV valves (tricuspid and mitral).
• The "dub" sound is caused by the closure of the semilunar valves (pulmonary and aortic).

Heart Murmurs

• Murmurs are abnormal heart sounds resulting from turbulent blood flow.

Cardiac Cycle

• Systole refers to the contraction phase of the heart.
• Diastole refers to the relaxation phase of the heart.

Vital Signs & Contraindications

• Vital signs include blood pressure (BP), temperature, pulse, and respiration.
• Contraindications for taking vital signs may include certain conditions or situations.

Cardiovascular Disorders

• Coronary artery disease (CAD): narrowing of the coronary arteries.
• Congestive heart failure (CHF): heart's inability to pump effectively.
• Hypertension (HTN): high blood pressure.
• Angina: chest pain due to insufficient blood flow to the heart muscle
• Myocardial infarction (MI): heart attack (death of heart tissue).
• Thrombus/Embolus: blood clot.
• Aneurysm: weakened/bulging artery wall.
• Cerebrovascular accident (CVA): stroke (blood supply to the brain interrupted).
• Treatments for these disorders vary greatly.

Cardiac Output, Stroke Volume, & Blood Pressure

• These are important cardiovascular parameters to track and are significant in assessing the heart's function.
• Cardiac output: volume of blood pumped by the heart per minute.
• Stroke volume: volume of blood pumped by the left ventricle per beat.
• Blood pressure: pressure exerted by blood against the artery walls (systolic over diastolic pressure).

Test your knowledge on the anatomy and physiology of the heart! This quiz covers the four chambers of the heart, the structure of the pericardium, and the blood flow through the heart. Ensure you understand how the heart's valves and muscles work together to maintain proper circulation.