objective 14 Flashcards
area on the anterior chest overlying the heart and great vessels
precordium
area where the heart and great vessels are located; between the
lungs in the middle third of the thoracic cage
mediastinum
bottom of the heart
apex
top of the heart
base
Superior and inferior venae cavae, pulmonary artery,
pulmonary veins, and aorta
great vessels
Right side is anterior, left side is mostly
posterior
right and left cardiac boarders
Double-walled sac that surrounds and protects the heart
* 2 layers that contain pericardial fluid in-between
* Adherent to the great vessels, esophagus, sternum, and pleura
* Anchored to the diaphragm
pericardium
Muscular wall of the heart
* Responsible for “pumping”
myocardium
Thin layer of endothelial tissue that lines the inner surface of the
heart chambers and valves
endocardium
thin walled reservoir for holding blood
atrium
muscular pumping chamber
ventricle
separate the atria and ventricles
atrioventricular valves
right AV valve
tricuspid valve
left AV valve
mitral valve
located between the ventricles and the
pulmonary arteries
semilunar valves
right side of the heart
pulmonic valve
left side of the heart
aortic valve
Takes 2/3 of the cardiac cycle
* Ventricles relax and fill with blood
* AV valves are open
* Pressure is higher in atria then ventricles, blood pours rapidly into the
ventricles
diastole
takes 1/3 of the cardiac cycle
* Volume raise ventricular pressure higher than in atria, AV valves shut to
prevent backflow
* The heart contracts
* Blood is pumped from the ventricles and fills the pulmonary and systemic
arteries
systole
Specialized cells in the SA node near the superior venae cava initiate
an electrical impulse
SA (sinoatrial) Node
Current flows across the atria to the AV node low in the atrial septum
AV (atrioventricular) node
collection of heart muscle cells specialized for
electrical conduction
Current slightly delayed in AV node, then the impulse travels to the
Bundle of His
bundle of his
Bundle of His to right/left bundle branches to the ventricles
bundle branches
In a resting adult, the heart pumps normally between 4-6L of
blood per minute throughout the body
pumping ability
CO = Stroke volume X rate (number of beats per minute)
Cardiac output
Venous return that builds during diastole
* The length to which the ventricular muscle is stretched just before
contraction
preload
Opposing pressure that the ventricle must generate to open
the aortic valve against the higher aortic pressure
* Resistance against which the ventricle must pump its blood
* To overcome the difference in the ventricular end-diastolic
pressure and that in the aorta, the ventricular muscle tenses
(isovolumic contraction) and after the valve opens rapid
ejection occurs
afterload
S1 and S2
normal heart sounds
sometimes also heard, S3, S4
extra heart sounds
Occurs with
closure of the
AV valves
* Signals the
beginning of
systole
* Although the
mitral valve
closure slightly
precedes the
tricuspid, they
usually sound
like one sound
when
auscultating
* Louder at the
apex
S1