| Question |
Answer |
| when in the cardiac cycle is O2 consumption highest? |
isovolumetric contraction |
| this is the period between mitral valve closing and aortic valve opening |
isovolumetric contraction |
| this is the period between aortic valve opening and closing |
systolic ejection |
| this is the period between aortic valve closing and mitral vale opening |
isovolumetric relaxation |
| when does rapid filling occur? |
just after mitral valve opens |
| when does slow filling occur? |
just before mitral valve closes |
| when is JVD seen? |
right heart failure |
| what is cardiac muscle contraction dependent on? |
extracellular calcium, which enters the cells during plateau of action potential and stimulates calcium release from the sarcoplasmic reticulum (calcium-induced calcium release) |
| what is the plateau in the cardiac muscle action potential due to? |
calcium influx |
| where does the pacemaker action potential occur? |
SA and AV nodes |
| what accounts for the automaticity of the SA and AV nodes? |
slow diastolic depolarization - membrane potential spontaneously depolarizes as Na+ conductance increases (funny channel) |
| what determines heart rate? |
slope of phase 4 in the SA node |
| what are the peripheral chemoreceptors? what do they respond to? |
carotid and aortic bodies - they respond to decreased (less than 60 mmHg)/increased PCO2, decreased pH of blood |
| what do central chemoreceptors respond to? |
changes in pH and PCO2 of brain interstitial fluid, which in turn are influenced by arterial CO2 |
| what does the aortic arch respond to? how does it transmit and to where? |
responds to increased BP; transmits via vagus to medulla |
| how and to where does the carotid sinus transmit information? |
via glossopharyngeal to the medulla |
| how do the central chemoreceptors respond to increased intracranial pressure? |
hypertension (sympathetic response) and bradycardia (parasympathetic response) |
| what organ receives the larges share of systemic cardiac output? |
liver |
| what organ receivest eh highest blood flow per gramof tissue? |
kidney |
| how does the heart meet increased O2 demand? |
incrased coronary blood flow, not by increased extraction of O2 |
| hypoxia in the pulmonary vasculature causes what? |
vasoconstriction (unique because in other organs hypoxia causes vasodilation) |
| what are the local factors in the heart that determine autoregulaton? |
O2, adenosine, NO |
| what are the local factors in the brain that determine autoregulation? |
CO2 (pH) |
| how do the kidneys determine autoregulation? |
myogenic and tuboglomerular feedback |
| what local factors determine autoregulation in skeletal muscle? |
lactate, adenosine, K+ |
| what is the most important mechanism for determining autoregulation in the skin? |
sympathetic stimulation - temperature control |
| what is the effect of carotid massage? |
incrases pressure on carotid artery - increasing stretch and leading to decreased HR |
| what is the ultimate consequence of baroreceptors sensing hypotension? |
vasoconstriction, incrased HR, contractility, and BP - important in the response to severe hemorrhage |
| sound of mitral and tricuspid valve closure |
S1 |
| sound of aortic and pulmonary valve closure |
S2 |
| sound at end of rapid ventricular filling |
S3 |
| sound from high atrial pressure/stiff ventricle |
S4 |
| what is S3 associated with? |
dilated CHF, mitral/tricuspid regurgitation |
| what is S4 (atrial kick) associated with? |
hypertrophic ventricle |
| what is paradoxical splitting associated with? |
aortic stenosis, LBBB |
| what is fixed splitting associated with? |
ASD |
| holosystolic high pitched 'blowing murmur' loudest at apex |
mitral regurg (tricuspid regurg) |
| cresecendo-decrescendo systolic ejection murmur following ejection click |
aortic (pulmonic) stenosis |
| pulsus parvus et tardus |
pulses weak compared to heart sounds; seen in aortic stenosis |
| holosystolic murmur |
VSD |
| late systolic murmur with midsystolic click |
mitral prolapse |
| immediate high-pitched blowing diastolic murmur; wide pulse pressure |
aortic regurgitation |
| delayed rubbing late diastolic murmur that follows opening snap |
mitral stenosis |
| how does the murmur in tricuspid stenosis differ from that of mitral stenosis? |
tricuspid stenosis differs because it gets louder with inspiration |
| continuous machine-like murmur |
PDA |
| when is the murmur associated with a PDA loudest? |
S2 |
Cardio Block2anatomy
