Exam 2 Study Guide: Cardiopulmonary Anatomy and Physiology

Vocabulary flashcards covering blood composition and function, heart anatomy, cardiac physiology, autonomic reflexes, pulmonary and systemic circulation, heart layers, and standard blood laboratory units.

Red Blood Cells (Erythrocytes)

The most abundant type of blood cell in circulation, responsible for oxygen transport throughout the body.

Platelets (Thrombocytes)

Cell fragments in the blood that function to prevent blood loss by forming blood clots.

Eosinophil

A type of white blood cell whose elevated count typically indicates an allergic reaction or parasitic infection.

Neutrophil

A type of white blood cell whose increase typically signals a bacterial infection.

Capacitance Vessels

A term referring to veins because of their capacity to store large volumes of blood within the circulatory system.

Superior Vena Cava

A major vein that returns deoxygenated blood from the upper body to the right atrium of the heart.

Inferior Vena Cava

A major vein that returns deoxygenated blood from the lower body to the right atrium of the heart.

Pulmonary Trunk

A major blood vessel that emerges from the right ventricle and branches into the pulmonary arteries to carry deoxygenated blood to the lungs.

Right Atrium

The heart chamber that receives deoxygenated blood from the superior vena cava, inferior vena cava, and coronary sinus.

Left Atrium

The heart chamber that receives oxygenated blood returning from the lungs via the pulmonary veins.

Right Ventricle

The heart chamber that pumps deoxygenated blood into the pulmonary trunk toward the lungs.

Left Ventricle

The thick-walled heart chamber that pumps oxygenated blood into the aorta to supply systemic circulation.

Aorta

The largest systemic artery in the body, carrying oxygenated blood from the left ventricle out to systemic circulation.

Preload

The degree of stretch on the myocardial fibers at the end of diastole, just before cardiac contraction.

Afterload

The arterial pressure or vascular resistance that the ventricles must overcome to eject blood during systole.

Contractility

The intrinsic ability and force of myocardial muscle cells to contract at any given preload.

Inotropism

Factors affecting myocardial contractile force, where positive inotropism increases contractile force and negative inotropism decreases force.

Chronotropism

Factors affecting heart rate, where positive chronotropism increases rate and negative chronotropism decreases rate.

Baroreceptors

Pressure-sensitive receptors in blood vessels that trigger reflex responses, such as increasing heart rate and causing arteriolar constriction when arterial pressure drops.

Systemic Circuit

The vascular network that carries oxygenated blood from the heart to the body tissues and returns deoxygenated blood to the heart.

Pulmonary Circuit

The vascular network that carries deoxygenated blood from the heart to the lungs for gas exchange and returns oxygenated blood to the heart.

Pulmonary Vascular Resistance (PVR)

The resistance in the pulmonary blood vessels, calculated as mean arterial pressure (MAP) or pressure gradient divided by blood flow.

Active Mechanisms of PVR

Physiological controls including neural stimulation, humoral agents, and blood gas levels that actively alter pulmonary vascular resistance through vasoconstriction or vasodilation.

Passive Mechanisms of PVR

Physical and mechanical factors—including changes in lung volume, vascular recruitment, and blood flow—that passively alter pulmonary vascular resistance.

Pathologic Conditions Raising PVR

Disease processes that increase pulmonary vascular resistance through vessel obstruction, obliteration, or external compression.

Endocardium

The inner endothelial tissue layer lining the internal chambers and valves of the heart.

Myocardium

The middle muscular layer of the heart wall responsible for pumping blood through contraction.

Pericardium

The protective fibroserous membrane sac that surrounds and encloses the heart.

Red Blood Cell Count Unit

The standard diagnostic unit used to quantify erythrocytes in blood, expressed as $\text{million/mm}^3$.

White Blood Cell Count Unit

The standard diagnostic unit used to quantify total leukocytes in blood, expressed as $\text{cells/mm}^3$.

Platelet Count Unit

The standard diagnostic unit used to quantify thrombocytes in blood, expressed as $\text{cells/mm}^3$.