Heart
cone shaped; size of your fist; double pump system
Heart chambers
right and left atria: smaller than ventricles; receives blood
right and left ventricle; pumps blood
Pericardium
heart is covered by a serous membrane called
3 layers of the heart wall
Epicardium, Myocardium, Endocardium
Epicardium
Outer protective layer
Myocardium
Middle muscular layer
Endocardium
inner layer
Pulmonary circulation
first 2 pumps; arteries carry deoxygenated blood and veins carry
oxygenated blood
Systemic circulation
the pumps after going in the lungs; arteries carry oxygenated blood
and veins carry deoxygenated blood
Valves
prevent blood from going in the wrong direction
Left atrioventricular valve
Mitral valve
Right atrioventricular valve
Tricuspid valve
Order of blood flow
Vena cava- R atrium- tricuspid valve- R ventricle- pulmonary trunk
arteries- lungs- pulmonary veins- L atrium- L ventricle- aorta
P wave
depolarization of the atria
QRS complex
ventricular depolarization and ventricular contraction
T wave
ventricular depolarization
Cardiac cycle
one complete heart beat; lasts .8 second; 75 beats per minute
Tachycardia
resting heart rate above 100 beats
Bradycardia
resting heart rate below 60 beats
Fibrillation
rapid uncoordinated; fails to pump blood out of heart
diastole
ventricular relaxation
systole
ventricular contraction
Blood pressure
measured in arteries; normal is 120/80
hypertension; 140/90 or higher
hypotension; 90/60 or lower
sound of Korotkoff
hearing blood through a stethoscope using sphygmomanometer
heart sound: lub
1st sound; closure of the AV valves
heart sound: dub
2nd sound; closer of the semilunar valves