Conductive pathway
known as the pacemaker, a specialized clump of myocardial conducting cells located in the superior portion of the right atrium that has the highest inherent rate of depolarization that then spreads throughout the heart
sinoatrial (SA) node
random electrical signals result in no pumping action; hallmark of myocardial infarction (MI) and quickly fatal
Ventricular Fibrillation
oval-shaped depression in the interatrial septum that marks the former location of the foramen ovale
fossa ovalis
large arterial vessel that carries blood ejected from the right ventricle; divides into the left and right pulmonary arteries
pulmonary trunk
Louder and longer “lubb,” occurs with
closure of AV valves, turbulence in the bloodstream, and movements of the heart wall
First heart sound ( S1)
specialized myocardial conductile cells that arise from the bifurcation of the atrioventricular bundle and pass through the interventricular septum
atrioventricular bundle branches (also, left or right bundle branches)
What is associated with atrial depolarization and atrial contraction?
P wave
valves located at the base of the pulmonary trunk and at the base of the aorta
semilunar valves
large systemic vein that returns blood to the heart from the superior portion of the body
superior vena cava
results from the failure of either ventricle to eject blood effectively, Usually due to a heart weakened by myocardial infarction, chronic
hypertension, valvular insufficiency, or congenital defects in heart
structure
Congestive Heart Failure
specialized myocardial conduction fibers that arise from the bundle branches and spread the impulse to the myocardial contraction fibers of the ventricles
Purkinje fibers
What is associated with ventricular repolarization & ventricular relaxation?
T wave
cavity surrounding the heart filled with a lubricating serous fluid that reduces friction as the heart contracts
pericardial cavity
Vessels that carry highly oxygenated blood into the left atrium, which pumps the blood into the left ventricle, which in turn pumps oxygenated blood into the aorta and to the many branches of the systemic circuit
pulmonary veins
sum of forces a ventricle must overcome before it can
eject blood, Ex: Blood pressure in the aorta, pulmonary trunk is most significant
contribution
Afterload
clump of myocardial cells located in the inferior portion of the right atrium within the atrioventricular septum; receives the impulse from the SA node, pauses, and then transmits it into specialized conducting cells within the interventricular septum
atrioventricular (AV) node
What is associated with ventricular depolarization and ventricular contraction as well as atrial repolarization and atrial relaxation?
QRS Complex
one-way valves located between the atria and ventricles; the valve on the right is called the tricuspid valve, and the one on the left is the mitral or bicuspid valve
atrioventricular valves
surround the alveoli of the lungs where gas exchange occurs: carbon dioxide exits the blood and oxygen enters
pulmonary capillaries
communicates with heart via
right and left cardiac nerves carrying sympathetic
postganglionic nerve fibers
Cardioacceleratory center
factors that negatively impact or lower heart contractility
negative inotropic factors
Ventricular Plateau Phase is seen by what segment?
S-T Segment
branches of the ascending aorta that supply blood to the heart; the left coronary artery feeds the left side of the heart, the left atrium and ventricle, and the interventricular septum; the right coronary artery feeds the right atrium, portions of both ventricles, and the heart conduction system
coronary arteries
Cusps are stiffened and opening is
constricted by scar tissue; regurgitation can be heard as a heart murmur
Valvular stenosis
Phases of the cardiac cycle
1. Ventricular filling
2. Isovolumetric contraction
3. Ventricular ejection
4. Isovolumetric relaxation