Unit 6 - Cardiac Physiology Flashcards
Heart is composed of what three components?
Arteries, Veins, Septum
Arteries
carry blood away from the ventricles to tissues
Veins
Vessels that return blood from tissues to the atria
Septum
continuous muscular partition that prevents mixture of blood from the two sides of heart
Blood flow though heart
Inferior/superior vena cava, right atrium, right AV valve (tricuspid), right ventricle, pulmonary valve, pulmonary artery, lungs, pulmonary veins, left atrium, left AV valve (micuspid), left centricle, aortic valve, aorta.
Three things pulmonary circulation does (R heart)
- Circuit of vessels carrying blood between heart and lungs
- lungs add O2 and remove CO2
- flows through pulmonary veins to LA
Two things Systemic circulation does (L heart)
- circuit of vessels carrying blood between heart and body systems
- oxygen rich blood pumped from LA to LV to body through aorta
What side of the heart has oxygen rich blood?
left side
What side of the heart has de-oxygenated blood?
right side
Coronary Circulation
Coronary arteries on outside of heart and come from aorta. Per fused from aorta during diastole.
Right coronary artery supplies blood to
right side of heart
Left coronary artery supplies blood to
left side of heart
AV valves
R & L valves are positioned b/w atria and ventricles to prevent back-flow of blood from ventricles into atria during ventricular emptying
Right AV valve
tricuspid valve
Left AV valve
bicuspid valve
Chordae tendinae
fibrous cords prevent valves from being everted and papillary muscles
Heart valves pressure
atrial pressures not much higher than venous pressures
What is partially compressed during atrial contraction
superior, inferior venae cavae and pulmonary vein
Three things semi-lunar valves do
- aortic and pulmonary valves
- lie at juncture where major arteries leave ventricles
- prevented from everting by anatomic structure and positioning of cusps
Electrical Activity of Heart
heart beats rhythmically as result of action potentials it generates by itself
two specialized types of cardiac muscle cells
- contractile cells
2. auto rhythmic cells (pacemaker cells)
Contractile cells
99% of cardiac muscle cells. Contract-do mechanical work pumping. RMP is -80 mV with threshold of -40 mV
Autorhythmic cells
1% of cardiac muscle cells. Initiate & conduct action potentials that result in contraction of working cells. Do not contract no RMP
4 locations of pacemaker cells
- SA node
- AV node
- Bundle of His
- Purkinje fibers