Chapter 22: Cardiovascular System and Heart Anatomy

Comprehensive vocabulary flashcards covering Chapter 22 lecture notes on the cardiovascular system, including cardiac anatomy, chambers, valves, coronary and systemic circulation, the intrinsic conduction pathway, and cardiac cycle physiology.

Cardiovascular System

The organ system composed of the heart, blood, and blood vessels (arteries, veins, and capillaries).

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood to the heart.

Great Vessels

Major blood vessels that enter and leave the heart.

Heart Valves

Four structures within the heart that prevent backward blood flow, regulated by pressure differences on opposite sides.

Systole

Contraction phase of the heart muscle that raises pressure during ventricular ejection and pushes blood forward.

Diastole

Relaxation phase of the heart muscle that allows chambers and ventricles to fill with blood.

Blood Pressure

Force of blood pushing against blood vessel walls, measured in millimeters of mercury ($\text{mmHg}$).

Pericardium

Tough, protective sac surrounding the heart that protects and anchors it, limits excessive movement and stretching, and reduces friction.

Fibrous Pericardium

Tough, relatively inelastic outer layer made of dense connective tissue that protects and anchors the heart.

Serous Pericardium

Thin membrane composed of two layers: the parietal layer and the visceral layer.

Parietal Layer

Outer layer of the serous pericardium that lines the inner surface of the fibrous pericardium.

Visceral Layer (Epicardium)

Inner layer of the serous pericardium that directly covers the heart's surface.

Pericardial Cavity

Space between the two serous pericardial layers containing fluid that reduces friction during heartbeats.

Atria

The two superior upper chambers of the heart that receive blood.

Ventricles

The two larger inferior lower chambers of the heart that pump blood out of the heart.

Auricles

Ear-shaped muscular pouches extending from each atrium that increase the atria's capacity to hold blood.

Coronary Sulcus

Groove on the heart's surface separating the atria from the ventricles.

Anterior Interventricular Sulcus

Groove on the front surface of the heart located between the ventricles.

Posterior Interventricular Sulcus

Groove on the back surface of the heart located between the ventricles.

Fibrous Skeleton of the Heart

Dense fibrous connective tissue (primarily dense irregular connective tissue) that mainly surrounds the valves, provides structural support to valves and cardiac muscle, and electrically insulates atria from ventricles.

Right Atrium

Heart chamber that receives deoxygenated blood from the body and heart muscle.

Superior Vena Cava

Large vein that returns deoxygenated blood from the upper body to the right atrium.

Inferior Vena Cava

Large vein that returns deoxygenated blood from the lower body to the right atrium.

Coronary Sinus

Vessel that collects blood from the major coronary veins and empties most venous blood from the heart muscle into the right atrium.

Right AV Valve (Tricuspid Valve)

Valve separating the right atrium and right ventricle that closes at the beginning of right ventricular contraction to prevent backflow into the right atrium.

First Heart Sound ("Lub")

Heart sound caused by the closure of the atrioventricular (AV) valves at the beginning of ventricular systole.

Second Heart Sound ("Dub")

Heart sound caused by the closure of the semilunar valves at the beginning of ventricular diastole.

Right Ventricle

Chamber that receives deoxygenated blood from the right atrium and pumps it toward the lungs.

Papillary Muscles

Muscular projections attached to chordae tendineae that help prevent AV valve prolapse during ventricular contraction.

Chordae Tendineae

Tendon-like cords connecting papillary muscles to AV valve cusps to prevent them from flipping backward into the atrium.

Trabeculae Carneae

Irregular muscular ridges lining the inside of the ventricles that form part of the ventricular muscle structure.

Conus Arteriosus

Smooth, funnel-shaped upper portion of the right ventricle leading toward the pulmonary trunk.

Pulmonary Semilunar Valve

Valve located between the right ventricle and the pulmonary trunk that prevents blood from flowing backwards into the ventricle.

Interventricular Septum

Thick muscular wall separating the right and left ventricles.

Left Atrium

Chamber that receives oxygen-rich blood returning from the lungs.

Pulmonary Veins

Veins that carry oxygenated blood from the lungs to the left atrium.

Left AV Valve (Mitral or Bicuspid Valve)

Two-cusped valve that closes when the left ventricle contracts and ventricular pressure exceeds atrial pressure, preventing backflow into the left atrium.

Left Ventricle

Chamber with a thicker myocardial wall that pumps oxygen-rich blood into the aorta and throughout the body.

Aortic Semilunar Valve

Valve located between the left ventricle and the aorta that prevents backflow into the left ventricle.

Myocardium

Muscular middle layer of the heart wall responsible for contraction; thicker in the left ventricle to generate higher pressure.

Systemic Circulation

Circulatory pathway that carries oxygen-rich blood from the left heart to body tissues and returns oxygen-poor blood to the right heart.

Pulmonary Circulation

Circulatory pathway that carries oxygen-poor blood from the right heart to the lungs and returns oxygen-rich blood to the left heart.

Coronary Circulation

Circulation pathway that supplies oxygen and nutrients to the heart muscle (myocardium) and removes waste.

Right Marginal Artery

Artery that supplies the right border of the heart, especially the right ventricle.

Posterior Interventricular Artery

Artery usually branching from the right coronary artery that supplies portions of the posterior/inferior ventricles and interventricular septum.

Anterior Interventricular Artery

Branch of the left coronary artery that supplies anterior portions of both ventricles and most of the interventricular septum.

Circumflex Artery

Branch of the left coronary artery that supplies portions of the left atrium and left ventricle.

Great Cardiac Vein

Coronary vein that travels alongside the anterior interventricular artery.

Middle Cardiac Vein

Coronary vein that travels alongside the posterior interventricular artery.

Small Cardiac Vein

Coronary vein that travels near the right marginal artery.

Intercalated Discs

Specialized connections between cardiac muscle cells that allow coordinated contractions.

Gap Junctions

Channels within intercalated discs that allow electrical signals to pass rapidly between cardiac muscle cells.

Autorhythmicity

Ability of the heart to generate its own electrical impulses without requiring nervous system stimulation.

Sinoatrial (SA) Node

The heart's natural pacemaker located in the upper right atrium near the opening of the superior vena cava; normally starts each heartbeat.

Atrioventricular (AV) Node

Conduction structure located in the lower interatrial septum near the floor of the right atrium that briefly delays the electrical impulse.

AV Bundle (Bundle of His)

Pathway that carries electrical impulses from the AV node into the interventricular septum.

Bundle Branches

Right and left branches that carry electrical impulses along the interventricular septum toward the apex.

Purkinje Fibers

Specialized fibers that spread electrical impulses through ventricular myocardium, producing coordinated contraction from the apex upward.

Electrical Conduction Pathway

The orderly path of cardiac conduction: $\text{SA node} \rightarrow \text{Atria} \rightarrow \text{AV node} \rightarrow \text{AV bundle} \rightarrow \text{Right \& left bundle branches} \rightarrow \text{Purkinje fibers}$.

Sympathetic Nervous System

Autonomic division that increases heart rate and the force of contraction.

Parasympathetic Nervous System

Autonomic division that slows heart rate, mainly acting through the vagus nerve.

Cardiac Cycle

All events occurring from the beginning of one heartbeat to the beginning of the next, lasting approximately $0.8\text{ seconds}$ at a heart rate of $75\text{ beats/minute}$.

Depolarization

Electrical activation that triggers muscle contraction.

Passive Ventricular Filling

Flow of blood from the atria into the relaxed ventricles without requiring atrial contraction, accounting for about $70\text{--}80\%$ of ventricular filling at rest.

Atrial Systole

Contraction of the atria that provides the remaining ventricular filling after passive filling.

Systolic Blood Pressure

Pressure in the systemic arteries during ventricular contraction, conventionally referenced at $120\text{ mmHg}$ in normal adult blood pressure ($120/80\text{ mmHg}$).

Diastolic Blood Pressure

Pressure in the systemic arteries during ventricular relaxation, conventionally referenced at $80\text{ mmHg}$ in normal adult blood pressure ($120/80\text{ mmHg}$).