Cardiovascular System Key Words

apex

the lower tip of the heart

pericardium

the double-walled membranous sac that encloses the heart

parietal pericardium

the fibrous outer sac of the pericardium

pericardial fluid

the thing that is found between the two layers of the pericardium to act as a lubricant between them during heartbeats

visceral pericardium; epicardium

the inner layer of the pericardium that also forms the outer layer of the heart (TWO DISTINCT BUT SYNONYMOUS NAMES!)

myocardium

the middle and thickest of the heart’s three layers that consists of cardic muscle tissue

endocaridum

the inner lining of the heart that consists of epithelial tissue and is the surface that comes into direct contact with the blood pumped through the heart

coronary arteries

arteries that supply blood to the myocardium

atria

the two upper chambers of the heart that receive blood entering the heart

interatrial septum

the wall that divides the two atria of the heart

septum

a wall that separates two chambers

ventricles

the two lower chambers of the heart that pump blood throughout the body

interventricular septum

the wall that divides the two ventricles of the heart

tricuspid valve

the valve that controls the opening between the right atrium and the right ventricle; has three cusps (points)

pulmonary valve

the valve located between the right ventricle and the pulmonary artery

mitral valve; bicuspid valve

the valve located between the left atrium and the left ventricle; has two cusps (points) (2 NAMES)

aortic valve

the valve located between the left ventricle and the aorta

pulmonary circulation

the blood circulation system between only the heart and lungs

pulmonary arteries

arteries that carry deoxygenated blood out of the right ventricle and into the lungs

pulmonary veins

veins that carry oxygenated blood from the lungs to the left atrium of the heart

systemic circulation

the blood circulation system between heart and the rest of the body except the lungs

conduction system of the heart

a system of specialized myocytes in the heart that conduct the electrical impulses to stimulate heartbeats

sinoatrial node

a node of specialized myocytes located in the posterior wall of the right atrium near the entrance of the superior vena cava that initiates the basic rhythm and rate of the heartbeat; its impulse spreads over the atria, causing them to contract to force blood into the ventricles; also known as the “natural pacemaker”

atrioventricular node

a node of specialized myocytes located on the floor of the right atrium near the interatrial septum that transmits electrical impulses from the SA node to the bundle of His

bundle of His; AV bundle

a group of fibers located in the interventricular septum that carry electrical impulses to the right and left ventricles and the Purkinje fibers to ensure the sequence of heart contractions

Purkinje fibers

specialized conductive fibers located within the walls of the ventricles that relay electrical impulses to the cells of the ventricles to cause the ventricles to contract

electrocardiogram

a record of the electrical activity of the heart that gives important information of the spread of electricity to the different parts of the heart and is used for diagnostic purposes

sinus rhythm

normal beating/rhythm of the heart

P wave

a type of wave recorded on an EKG that is first caused by the depolarization of the atria, which in turn leads to atrial contractions

QRS complex

a type of wave recorded on an EKG that follows P waves and correspond to the depolarization of the ventricular muscles