Cardiovascular System Essentials

Vocabulary flashcards covering key terms, structures, and physiological concepts of the cardiovascular system discussed in the lecture.

Blood

Connective tissue that transports gases, nutrients, hormones, and wastes while helping regulate pH, temperature, and osmotic pressure.

Plasma

Liquid portion of blood composed mainly of water, proteins, salts, and lipids.

Red Blood Cells (Erythrocytes)

Cells containing hemoglobin that transport oxygen and carbon dioxide.

Hemoglobin

Iron-rich protein in red blood cells that binds oxygen and gives blood its red color.

White Blood Cells (Leukocytes)

Immune cells that defend the body against infection and foreign substances.

Platelets (Thrombocytes)

Cell fragments that initiate blood clotting to prevent bleeding.

Artery

Blood vessel that carries blood away from the heart; usually oxygen-rich except in pulmonary circulation.

Vein

Blood vessel that returns blood to the heart; usually oxygen-poor except in pulmonary circulation.

Capillary

Microscopic vessel where exchange of gases, nutrients, and wastes occurs between blood and tissues.

Pulmonary Circulation

Circuit in which pulmonary arteries carry oxygen-poor blood to the lungs and pulmonary veins return oxygen-rich blood to the heart.

Right Atrium

Upper right heart chamber that receives deoxygenated blood from the body via the venae cavae.

Right Ventricle

Lower right heart chamber that pumps deoxygenated blood to the lungs through the pulmonary artery.

Left Atrium

Upper left heart chamber that receives oxygenated blood from the lungs via pulmonary veins.

Left Ventricle

Lower left heart chamber that pumps oxygenated blood into the aorta for systemic circulation.

Valve

One-way structure preventing backflow of blood between heart chambers or into vessels.

Tricuspid Valve

Valve between the right atrium and right ventricle.

Pulmonary Valve

Valve between the right ventricle and pulmonary artery.

Mitral (Bicuspid) Valve

Valve between the left atrium and left ventricle.

Aortic Valve

Valve between the left ventricle and aorta.

Vena Cava

Major vein returning deoxygenated blood to the right atrium; divided into superior and inferior sections.

Aorta

Largest artery that distributes oxygenated blood from the left ventricle to the body.

Coronary Arteries

Vessels branching from the aorta that supply oxygen and nutrients to heart muscle.

Coronary Veins

Vessels that remove deoxygenated blood from heart tissue and empty into the coronary sinus.

Coronary Sinus

Large vein on the posterior heart that returns coronary blood to the right atrium.

Septum

Muscular wall separating the right and left sides of the heart.

Septal Defect

Abnormal opening in the septum allowing mixing of oxygen-rich and oxygen-poor blood.

Atrial Septal Defect (ASD)

Opening in the interatrial septum causing blood mixing between atria.

Ventricular Septal Defect (VSD)

Opening in the interventricular septum causing blood mixing between ventricles.

Sinoatrial (SA) Node

Primary pacemaker in the right atrium initiating each heartbeat at 60-100 bpm.

Atrioventricular (AV) Node

Secondary pacemaker that delays impulses, allowing atrial contraction before ventricular activation; intrinsic rate 40-60 bpm.

Bachmann’s Bundle

Interatrial pathway that rapidly conducts impulses from the SA node to the left atrium.

Bundle of His

High-speed fibers transmitting impulses from the AV node into the interventricular septum.

Right Bundle Branch

Pathway conveying impulses to the right ventricle.

Left Bundle Branch

Pathway conveying impulses to the left ventricle.

Purkinje Fibers

Network that distributes electrical impulses to ventricular muscle, intrinsic rate 20-40 bpm.

Electrocardiogram (ECG/EKG)

Recording of the heart’s electrical activity used to assess rhythm and conduction.

Isoelectric Line

Baseline on an ECG representing no net electrical activity.

P Wave

ECG deflection representing atrial depolarization (atrial contraction).

QRS Complex

Sharp ECG deflection representing ventricular depolarization; masks atrial repolarization.

T Wave

ECG deflection representing ventricular repolarization (ventricular relaxation).

Depolarization

Electrical change triggering cardiac muscle contraction.

Repolarization

Return of cardiac cells to resting state, allowing relaxation.

Systolic Pressure

Peak arterial pressure during ventricular contraction; the top number in a blood-pressure reading.

Diastolic Pressure

Lowest arterial pressure during ventricular relaxation; the bottom number in a blood-pressure reading.

Homeostasis

Stable internal environment maintained by physiological processes such as blood regulation of pH and temperature.