Heart Vocab and Anatomy

Arteries

Blood vessels that transport blood AWAY from the heart; usually carry oxygenated blood except pulmonary arteries

Veins

Blood vessels that transport blood TO the heart; usually carry deoxygenated blood except pulmonary veins

Capillaries

Smallest blood vessels where gas, nutrient, and waste exchange occurs between blood and tissues

Pulmonary Circulation

Blood circulation from right side of heart → lungs → left side of heart; purpose is gas exchange

Systemic Circulation

Blood circulation from left side of heart → body tissues → right side of heart; delivers oxygen and nutrients

Mediastinum

Middle compartment of thoracic cavity where the heart is located

Pericardium

Fibrous sac surrounding the heart; consists of fibrous and serous layers

Fibrous Pericardium

Tough, dense outer layer of pericardium that anchors heart and prevents overexpansion

Serous Pericardium

Inner double-layered membrane of pericardium with parietal and visceral layers

Pericardial Cavity

Potential space between parietal and visceral layers of serous pericardium containing lubricating fluid

Epicardium

Outermost layer of heart wall; same as visceral layer of serous pericardium

Myocardium

Middle layer of heart wall composed of cardiac muscle; thickest layer that generates contractile force

Myocardium

Endocardium

Innermost layer of heart wall that lines chambers and covers valve surfaces; smooth endothelial lining

Endocardium

Right Atrium

Upper right chamber that receives deoxygenated blood from superior vena cava, inferior vena cava, and coronary sinus

Right Atrium

Left Atrium

Upper left chamber that receives oxygenated blood from four pulmonary veins

Left Atrium

Right Ventricle

Lower right chamber that pumps deoxygenated blood to lungs via pulmonary trunk

Right Ventricle

Left Ventricle

Lower left chamber that pumps oxygenated blood to body via aorta; has walls 3x thicker than right ventricle

Left Ventricle

Interatrial Septum

Wall separating right and left atria

Interatrial Septum

Interventricular Septum

Wall separating right and left ventricles

Interventricular Septum

Fossa Ovalis

Oval depression in interatrial septum; remnant of fetal foramen ovale

Fossa Ovalis

Pectinate Muscles

Muscular ridges found in anterior walls and auricles of atria

Trabeculae Carneae

Large, irregular muscular ridges on interior surfaces of ventricles

Trabeculae Carneae

Right atrioventricular valve

Tricuspid Valve with three cusps; prevents backflow from right ventricle to right atrium

Right atrioventricular valve

Left atrioventricular valve

Bicuspid Valve with two cusps; also called mitral valve; prevents backflow from left ventricle to left atrium

Left atrioventricular valve

Pulmonary Semilunar Valve

Valve with three half-moon cusps between right ventricle and pulmonary trunk

Pulmonary Semilunar Valve

Aortic Semilunar Valve

Valve with three half-moon cusps between left ventricle and aorta

Aortic Semilunar Valve

Chordae Tendineae

String-like connective tissue strands that attach AV valve cusps to papillary muscles

Superior Vena Cava

Large vein that returns deoxygenated blood from head, neck, upper limbs to right atrium

Superior Vena Cava

Inferior Vena Cava

Large vein that returns deoxygenated blood from lower limbs and trunk to right atrium

Inferior Vena Cava

Pulmonary Trunk

Large artery that carries deoxygenated blood from right ventricle; splits into right and left pulmonary arteries

Aorta

Large artery that carries oxygenated blood from left ventricle to systemic circulation

Aortic arch

Cardiac Muscle

Specialized muscle tissue of myocardium; short, branched cells with intercalated discs

Intercalated Discs

Specialized cell junctions in cardiac muscle containing desmosomes and gap junctions

Gap Junctions

Protein channels in intercalated discs that allow rapid electrical impulse transmission between cardiac cells

Desmosomes

Strong cell adhesions in intercalated discs that prevent cardiac muscle cells from separating during contraction

Autorhythmicity

Ability of heart to generate its own electrical impulses without external stimulation

Sinoatrial Node

Primary pacemaker of heart located in right atrial wall; initiates heartbeat at 70-80 beats per minute

Sinoatrial Node

Atrioventricular Node

Secondary pacemaker in right atrial floor that delays electrical impulse for 100 milliseconds

Atrioventricular Node

Atrioventricular Bundle

Bundle of His; conducts electrical impulses from AV node through fibrous skeleton to bundle branches

Atrioventricular Bundle

Bundle Branches

Right and left pathways in interventricular septum that conduct electrical impulses to Purkinje fibers

Right bundle branch

Left bundle branch

Purkinje Fibers

Subendocardial branches that rapidly distribute electrical impulses throughout ventricular myocardium

Purkinje Fibers

Systole

Contraction phase of cardiac cycle when chamber pressure increases and blood is ejected

Diastole

Relaxation phase of cardiac cycle when chamber fills with blood

"Lubb" sound

caused by closure of AV valves at start of ventricular systole

AV Valves close

"Dupp" sound

caused by closure of semilunar valves at start of ventricular diastole

Semilunar Valves close

Myocardial Infarction

Heart attack; death of heart muscle due to blocked coronary artery and lack of oxygen

Fibrous Skeleton

Dense connective tissue framework between atria and ventricles that anchors valves and provides electrical insulation