Heart Flashcards
QRS complex
Atrium repolarized ventricle depolarizers ventricle contraction occurs immediately
P wave of ECG
Depolarization of the atrium(left side) immediately starts to contract the atrium
T wave of ECG
Repolarization of ventricle
Systole
Contraction
Diastole
Relaxation of heart
Heart murmur
When one of the valves doesn’t work right
Step one in cycle(Middle p wave to r point on ECG) Chambers Pressure Valves Ventricle blood volume
Atrial systole Chambers: atria contracting, ventricle relaxed Pressure: ventricle<aortic Valves: AV open semilunar closed Blood volume: increase slightly
Early ventricle systole Chambers Pressure Valves Ventricular blood volume
Chambers: atria relax ventricle contract
Pressure: ventricle>atrial<aortic
Valves: AV closed semilunar closed
Blood: remains same(Isovolumetric contraction)
Stage 3(late ventricle systole) Chambers Pressure Valves Ventricular blood volume
Chambers: atria relax ventricle contract
Pressure: ventricle>atrial>aorta
Valves: AV closed semilunar open
Blood: decrease( blood expelled to aorta)
Early ventricle diastole( step 4 cycle) Chambers Pressure Valves Ventricle blood volume
Chambers: atria and ventricle relaxing
Pressure: ventricle>atrial<aorta
Valves: AV and semilunar both closed
Blood:same(Isovolumetric relaxation)
Late ventricle diastole( step 5 cycle) Chambers Pressure Valves Ventricular blood volume
Chambers: atria and ventricle relaxed
Pressure: ventricle<aorta
Valves: AV open semilunar closed
Blood: increases(from atrium to ventricle)
End systolic volume(EVS)
How much blood remains in the ventricle after it flows to the aorta
End diastolic volume(EDV)
How much blood is in the ventricle before contraction(full)
Stroke volume
How much is lost during contraction? EDV-ESV= stroke volume
Fluids move down______________ gradient
Pressure gradient
Cardiac output( ml per min)
Heart rate(HR) * stroke volume(SV) (Beats/min). (ml/beat)
Conduction system cardiac excitability
1) initiation, SA node initiates action potential
2) spread of AP is propagated throughout atria(the conduction system)
Cardiac muscle cells excitability
1) AP initiated in conduction is propagated across sacrolemma
2) muscle contractions thin slide past thick and sacromeres shorten within cells
Steps to extrinsic conduction system
1) sinoatrial(SA) node(pacemaker) generates impulse
2) impulses pause .1 sec at the atrial ventricular (AV) node
3) AV bundle connects atria and ventricle
4) bundle branches conduct impulses through intraventricular septum
5) purkinje fibers depolarize contractile cells of both ventricles
Pacemaker(AV) autorhythmicity
1) slow voltage gated Na channels open inflow changes potential from -60mv to -40mv
2) depolarization fast voltage gated Ca channels open inflow changes from -40mv to 0 mv
3) repolarization Ca channels close K opens and flows out potential returns to -60 and K closes
PR segment of ECG
AV node delay(.1sec)
ST segment of ECG
When ventricles are contracting and emptying
TP interval of ECG
When ventricles are relaxing and refilling
Junctional rhythm ECG reading
SA node is nonfunctional p waves absent heart paced by AV node 40-60 bpm
Second degree heart-block ECG reading
Some P waves aren’t conducted through AV node so more P than QRS seen
Ventricular fibrillation reading ECG
Chaotic grossly irregular seen in acute heart attack and electrical shock
Arteries? 2 major what side?
Pulmonary trunk transports to right side
Aorta transports to left side
Arteries take blood from the heart to the body
Veins? 2 major ones what side?
Vena cava(SVC &IVC) drain into right side Pulmonary veins drain into the left side
Veins bring blood into the heart
Right side of the heart
De oxygenated blood and weak AP
Left side of the heart
Oxygenated blood flows. The heavy conductor, has lg AP that contract the heart
Blood flow through pulmonary circulation
1) deoxygenated blood into rt qtrium from vena cavae and coronary sinus
2) blood passes through AV valve (tri)
3) enters right ventricle
4) passes through pulmonary semilunar valve
5) enters pulmonary trunk
6) continues through rt and lf pulmonary arteries to both lungs
7) gas exchanges in pulmonary capillaries
8) oxygenated blood returns to left side heart by pulmonary veins
9) enters lf atrium of heart
Tachycardia fast heart rate
Heart beat more than 100 beats per sec.
Bradycardia
Heart rare below 60 beats per min
Ventricle septic defect
Blood mixes between ventricles wall isn’t properly formed
Coarctation of the aorta
Aorta is narrowed increasing left vent work load
