The Cardiovascular System: The Heart

Flashcards for reviewing the cardiovascular system and heart anatomy.

Cardiovascular System

Pumps and delivers oxygen-poor blood to the lungs and oxygen-rich blood to the tissues; removes wastes from the tissues; transports cells, nutrients, and other substances.

Heart

The center of the cardiovascular system, responsible for nonstop pumping (average 75 beats per minute).

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood back to the heart.

Great Vessels

Arteries and veins entering and leaving the heart.

Pulmonary Circulation

Circulation that starts with the right side of the heart pumping deoxygenated blood to the lungs via pulmonary arteries, followed by oxygen pickup and return of oxygenated blood to the left side of the heart via pulmonary veins.

Systemic Circulation

Circulation where the left side of the heart pumps oxygenated blood through systemic arteries to the body's cells, and systemic veins carry deoxygenated blood back to the right side of the heart.

Heart Anatomy

Form relates to function, with cardiac muscle contracting to eject blood into the aorta and pulmonary trunk.

Heart Location

Located in the thoracic cavity between the lungs, behind the sternum, extending from the 2nd to the 5th intercostal space; approximately the size of a closed fist; weight 250-350 grams in adults; slightly tilted towards the left.

Mediastinum

The location of the heart within the thoracic cavity.

Atria

Upper chambers of the heart that receive blood.

Ventricles

Lower chambers of the heart that pump blood out of the heart.

Right Side of Heart

Handles deoxygenated blood.

Left Side of Heart

Handles oxygenated blood.

Vena Cavae

Great vessels that carry blood into the right atrium.

Pulmonary Trunk

Great vessel that carries blood from the right ventricle to the pulmonary arteries.

Pulmonary Veins

Great vessels that carry blood from the lungs to the left atrium.

Aorta

Great vessel that carries blood from the left ventricle to the body.

Myocardium

The muscular tissue of the heart.

Pericardium

The membrane enclosing the heart, consisting of the fibrous pericardium and serous pericardium (parietal and visceral layers).

Epicardium

The outer layer of the heart; thin serous membrane (visceral layer of pericardium) to reduce friction.

Myocardium

The middle and thickest layer of the heart, composed of cardiac muscle tissue responsible for heart contractions.

Endocardium

The inner layer of the heart; smooth endothelial tissue that lines heart chambers and covers heart valves.

Septum

Internal structure of the heart that divides the atria (interatrial) and ventricles (interventricular).

Atrioventricular Valves (AV)

Heart valves like the tricuspid and bicuspid/mitral valves, which prevent backflow from ventricles to atria. Closure causes the first heart sound 'lub'.

Semilunar Valves (SL)

Heart valves like the pulmonary and aortic valves at the base of great arteries, which prevent backflow from arteries to ventricles. Closure causes the second heart sound 'dup'.

Tricuspid Valve

Atrioventricular valve on the right side of the heart.

Mitral Valve (Bicuspid Valve)

Atrioventricular valve on the left side of the heart.

Pulmonary Valve

Semilunar valve on the right side of the heart.

Aortic Valve

Semilunar valve on the left side of the heart.

Right Atrium

Internal structure of the heart receiving blood from the superior vena cava, inferior vena cava, and coronary sinus; contains pectinate muscles and the fossa ovalis.

Left Atrium

Internal structure of the heart receiving blood from the pulmonary veins; lacks pectinate muscles.

Chordae Tendineae

Tendon-like cords that connect the atrioventricular valves to the papillary muscles in both ventricles.

Papillary Muscles

Muscles located in the ventricles that anchor the chordae tendineae.

Trabeculae Carneae

Irregular muscular ridges on the inner surfaces of the ventricles.

Coronary Circulation

The circulation of blood in the blood vessels that supply the heart muscle itself.

Right Coronary Artery

Supplies blood to the right side of the heart, branching into the marginal artery and posterior interventricular artery.

Left Coronary Artery

Supplies blood to the left side of the heart, branching into the circumflex artery and anterior interventricular artery.

Great Cardiac Vein

Coronary vein that drains blood from the area supplied by the anterior interventricular artery.

Middle Cardiac Vein

Coronary vein that drains blood from the area supplied by the posterior interventricular artery.

Small Cardiac Vein

Coronary vein that drains blood from the right margin of the heart.

Cardiac Muscle

Specialized type of muscle tissue found only in the heart, characterized by striated appearance, involuntary control, high resistance to fatigue, interconnected cells forming a functional syncytium, and intercalated discs for rapid electrical signal transmission.

Intercalated Discs

Specialized structures containing gap junctions to help propagate electrical impulses rapidly from cell to cell.

Sinoatrial (SA) Node

The natural pacemaker of the heart, initiating electrical signals (60-100 bpm) that trigger heart contractions.

Atrioventricular (AV) Node

Receives electrical signals the SA node and delays them briefly to allow the atria to contract before the ventricles.

Purkinje Fibers

Specialized conductive fibers that rapidly spread electrical signals throughout the ventricles, causing them to contract almost simultaneously.

Electrocardiogram (ECG)

A tracing of the electrical signals of the heart recorded by electrodes on the skin used to diagnose various heart conditions.

P Wave

Represents atrial depolarization (contraction) on an ECG.

QRS Complex

Represents ventricular depolarization (contraction) on an ECG.

T Wave

Represents ventricular repolarization (relaxation) on an ECG.

Systole

The phase of the cardiac cycle when the ventricles contract.

Diastole

The phase of the cardiac cycle when the ventricles relax.

Arrhythmias

Electrical disorders in the heart.