Cardiovascular System & Blood Flow

A set of practice questions and answers covering the major concepts from the lecture notes on the cardiovascular system, including anatomy, blood flow pathways, heart chambers and valves, coronary circulation, conduction system, neural regulation, ECG, cardiac cycle, and common heart conditions.

Which side of the heart receives oxygenated blood from the lungs via the pulmonary veins?

Left atrium (and then the left ventricle to the aorta for systemic circulation).

Which side of the heart receives deoxygenated blood from the body via the superior and inferior vena cavae?

Right atrium (then right ventricle to the lungs).

What vessel carries oxygenated blood from the left ventricle to the body?

Aorta.

What vessel carries deoxygenated blood from the right ventricle to the lungs?

Pulmonary trunk.

What is the approximate size and orientation of the heart?

Size of a fist (~10 ounces); base wide; apex tilts to the left.

What are the main components of the pericardium?

A double-walled sac with a parietal fibrous layer, a visceral serous layer, and a pericardial cavity containing 5–30 mL of fluid.

What is pericarditis?

Inflammation of the pericardial membranes.

What are the three layers of the heart wall?

Epicardium (visceral pericardium), Myocardium, Endocardium.

What is the epicardium and what does it contain?

Visceral pericardium; serous membrane with adipose and coronary vessels.

What is the endocardium?

Smooth inner lining that covers valve surfaces; continuous with endothelium.

What is the myocardium and its skeletal feature?

Cardiac muscle layer; spiral fibers; fibrous skeleton provides valve attachments and electrical insulation.

Name the four chambers of the heart.

Right atrium, Right ventricle, Left atrium, Left ventricle.

What are the auricles of the heart?

Appendages of the atria that enlarge the chamber.

What is the interatrial septum?

Wall that separates the right and left atria.

What are pectinate muscles and where are they found?

Internal ridges of myocardium in the right atrium and auricles.

What is the interventricular septum?

Wall that separates the right and left ventricles.

What are trabeculae carneae?

Internal ridges of the ventricles.

What do the atrioventricular and interventricular sulci contain?

Coronary arteries in the grooves separating chambers.

Which valves are the right and left AV valves?

Right AV valve is the tricuspid; Left AV valve is the mitral.

Which valves are semilunar valves?

Pulmonary valve and aortic valve.

What is the fossa ovalis?

Remnant of the foramen ovale in the right atrium.

What structures anchor the AV valves to prevent inversion during ventricular contraction?

Chordae tendineae and papillary muscles.

During ventricular diastole, which valves are open and which are closed?

AV valves open; semilunar valves closed.

When is coronary blood flow greatest and why?

During diastole, when the heart is relaxed and the coronary vessels are not compressed by systolic contraction.

Name the left coronary artery branches and their primary regions.

Anterior interventricular branch (supplies ventricles and most of the interventricular septum); Circumflex branch (supplies left atrium and posterior wall of the left ventricle).

Name the right coronary artery branches and their roles.

Right marginal branch (lateral right atrium/ventricle); Posterior interventricular branch (posterior walls of ventricles); also often supplies the SA node.

What is coronary artery disease (CAD) and its basic pathophysiology?

Constricted arteries from lipid deposits (atherosclerosis) due to endothelial damage, inflammation, and plaque formation reducing blood flow.

What is angina pectoris?

Chest pain caused by reduced coronary blood flow.

What are major risk factors for CAD?

High LDL cholesterol/dysfunctional receptors, aging, genetics, male sex, obesity, smoking, stress, and lack of exercise.

What are common treatments for CAD?

Bypass surgery, angioplasty, and stents.

What is a myocardial infarction?

Death (necrosis) of a patch of myocardium due to loss of blood supply.

What is the coronary sinus and where does it drain?

Large vein in the coronary sulcus that drains coronary veins into the right atrium.

What are cardiocytes and intercalated discs?

Cardiac muscle cells; intercalated discs are junctions that provide mechanical and electrical connections between cells.

What fuels the metabolic needs of cardiac muscle?

Fatty acids, glucose, lactic acid, and amino acids.

What is the heart’s conduction system sequence from the natural pacemaker to the ventricles?

Sinoatrial (SA) node → Atrioventricular (AV) node → AV bundle (bundle of His) → Purkinje fibers.

Which nerves increase heart rate and contraction?

Sympathetic nerves.

Which nerves decrease heart rate?

Parasympathetic nerves via the vagus nerve.

Where do parasympathetic fibers terminate to influence the heart?

Primarily at the SA and AV nodes.

What is the normal resting heart rate range for adults?

About 70–80 beats per minute.

What is an ECG's P wave, QRS complex, and T wave?

P wave = atrial depolarization; QRS complex = ventricular depolarization (atrial repolarization occurs); T wave = ventricular repolarization.

What are the major phases of the cardiac cycle?

Ventricular filling, isovolumetric contraction, ventricular ejection, isovolumetric relaxation.

What are typical end-diastolic and end-systolic volumes (EDV/ESV)?

EDV ~130 mL; ESV ~60 mL.

What do the first and second heart sounds (S1 and S2) reflect?

S1 = closure of the AV valves; S2 = closure of the semilunar valves.

What is cardiac output (CO) and its resting range?

Volume ejected per minute; typically about 4–6 L/min at rest.

What is cardiac reserve?

Difference between maximal and resting CO.

What is tachycardia and bradycardia?

Tachycardia: heart rate > 100 bpm; bradycardia: heart rate < 60 bpm.

What does Frank-Starling law state?

SV increases in response to an increase in EDV ( preload) when all other factors are constant.

Arterioclerosis

when the artery hardens due to fatty lipid buildup

Ischemia

When the heart is not supplying enough blood to the tissues and organs

What surrounds the cardiac muscle cells

glycogen

What kind of cell structure are cardiac muscle cells

Striated

What happens when lactic acid binds to the receptors in the heart

You get chest pain

Cardiac cell

myocyte or cardiocyte

Job of conductive cells

To signal the contractive cells on when to contract

SA node

Initiates electrical current to the rest of the heart through gap junctions and regulates heart rate.

“Fight or Flight” nerve

Sympathetic nerve

Sodium Potassium pump

A membrane protein that actively transports sodium out of and potassium into cells, crucial for maintaining cell membrane potential.

Amount of sodium potassium pump in 1 minute

300,000 NA in and 200,000 KT out of cells