EXAM 1 NUR 232 FUNCTION OF THE
HEART EXAM QUESTIONS AND
ANSWERS
- 3rANSWERS--The 3rcardiac 3rconduction 3rsystem 3rgenerates 3rand 3rtransmits
3relectrical 3rimpulses 3rthat 3rstimulate 3rcontraction 3rof 3rthe 3rmyo- 3rcardium. 3rUnder
3rnormal 3rcircumstances, 3rthe 3rconduction 3rsys- 3rtem 3rfirst 3rstimulates 3rcontraction
3rof 3rthe 3ratria 3rand 3rthen 3rthe 3rventricles. 3rThe 3rsynchronization 3rof 3rthe 3ratrial
3rand 3rventricular 3revents 3rallows 3rthe 3rventricles 3rto 3rfill 3rcompletely 3rbefore 3rven-
3rtricular 3rejection, 3rthereby 3rmaximizing 3rcardiac 3routput. 3rThree 3rphysiologic
3rcharacteristics 3rof 3rtwo 3rtypes 3rof 3rspecialized 3relec- 3rtrical 3rcells, 3rthe 3rnodal
3rcells 3rand 3rthe 3rPurkinje 3rcells, 3rprovide 3rthis 3rsynchronization:
• 3rAutomaticity: 3rability 3rto 3rinitiate 3ran 3relectrical 3rimpulse 3r• 3rExcitability: 3rability
3rto 3rrespond 3rto 3ran 3relectrical 3rimpulse 3r• 3rConductivity: 3rability 3rto 3rtransmit 3ran
3relectrical 3rimpulse
from 3rone 3rcell 3rto 3ranother 3rBoth 3rthe 3rsinoatrial 3r(SA) 3rnode 3r(the 3rprimary
3rpacemaker
of 3rthe 3rheart) 3rand 3rthe 3ratrioventricular 3r(AV) 3rnode 3r(the 3rsec- 3rondary
3rpacemaker 3rof 3rthe 3rheart) 3rare 3rcomposed 3rof 3rnodal 3rcells. 3rThe 3rSA 3rnode 3ris
3rlocated 3rat 3rthe 3rjunction 3rof 3rthe 3rsuperior 3rvena 3rcava 3rand 3rthe 3rright 3ratrium
3r(Fig. 3r25-3). 3rThe 3rSA 3rnode 3rin 3ra 3rnormal 3rresting 3radult 3rheart 3rhas 3ran
3rinherent 3rfiring 3rrate 3rof 3r60 3rto 3r100 3rimpulses 3rper 3rminute; 3rhowever, 3rthe
3rrate 3rchanges 3rin 3rresponse 3rto 3rthe 3rmetabolic 3rdemands 3rof 3rthe 3rbody
3r(Weber 3r& 3rKelley, 3r2010).
The 3relectrical 3rimpulses 3rinitiated 3rby 3rthe 3rSA 3rnode 3rare 3rcon- 3rducted 3ralong
3rthe 3rmyocardial 3rcells 3rof 3rthe 3ratria 3rvia 3rspecial- 3rized 3rtracts 3rcalled 3rinternodal
3rpathways. 3rThe 3rimpulses 3rcause
3r(L. 3r657)
L., 3rHinkle, 3rJ., 3rCheever, 3rH.. 3rBrunner 3r& 3rSuddarth's 3rTextbook 3rof 3rMedical-
Surgical 3rNursing, 3r13th 3rEdition. 3rLippincott 3rWilliams 3r& 3rWilkins, 3r12/2013.
3rVitalBook 3rfile.
What's 3rthe 3rfunction 3rof 3rcardiac 3rconduction 3rsystem? 3r- 3rANSWERS--generates
3rand 3rtransmits 3relectrical 3rimpulses 3rthat 3rstimulate 3rcontraction 3rof 3rthe 3rmyo-
3rcardium.
Conduction 3rsystem 3rkeeps 3rthings 3rin 3rorder. 3r
Under 3rnormal 3rcircumstances, 3rthe 3rconduction 3rsys- 3rtem 3rfirst 3rstimulates
3rcontraction 3rof 3rthe 3ratria 3rand 3rthen 3rthe 3rventricles.
HEART EXAM QUESTIONS AND
ANSWERS
- 3rANSWERS--The 3rcardiac 3rconduction 3rsystem 3rgenerates 3rand 3rtransmits
3relectrical 3rimpulses 3rthat 3rstimulate 3rcontraction 3rof 3rthe 3rmyo- 3rcardium. 3rUnder
3rnormal 3rcircumstances, 3rthe 3rconduction 3rsys- 3rtem 3rfirst 3rstimulates 3rcontraction
3rof 3rthe 3ratria 3rand 3rthen 3rthe 3rventricles. 3rThe 3rsynchronization 3rof 3rthe 3ratrial
3rand 3rventricular 3revents 3rallows 3rthe 3rventricles 3rto 3rfill 3rcompletely 3rbefore 3rven-
3rtricular 3rejection, 3rthereby 3rmaximizing 3rcardiac 3routput. 3rThree 3rphysiologic
3rcharacteristics 3rof 3rtwo 3rtypes 3rof 3rspecialized 3relec- 3rtrical 3rcells, 3rthe 3rnodal
3rcells 3rand 3rthe 3rPurkinje 3rcells, 3rprovide 3rthis 3rsynchronization:
• 3rAutomaticity: 3rability 3rto 3rinitiate 3ran 3relectrical 3rimpulse 3r• 3rExcitability: 3rability
3rto 3rrespond 3rto 3ran 3relectrical 3rimpulse 3r• 3rConductivity: 3rability 3rto 3rtransmit 3ran
3relectrical 3rimpulse
from 3rone 3rcell 3rto 3ranother 3rBoth 3rthe 3rsinoatrial 3r(SA) 3rnode 3r(the 3rprimary
3rpacemaker
of 3rthe 3rheart) 3rand 3rthe 3ratrioventricular 3r(AV) 3rnode 3r(the 3rsec- 3rondary
3rpacemaker 3rof 3rthe 3rheart) 3rare 3rcomposed 3rof 3rnodal 3rcells. 3rThe 3rSA 3rnode 3ris
3rlocated 3rat 3rthe 3rjunction 3rof 3rthe 3rsuperior 3rvena 3rcava 3rand 3rthe 3rright 3ratrium
3r(Fig. 3r25-3). 3rThe 3rSA 3rnode 3rin 3ra 3rnormal 3rresting 3radult 3rheart 3rhas 3ran
3rinherent 3rfiring 3rrate 3rof 3r60 3rto 3r100 3rimpulses 3rper 3rminute; 3rhowever, 3rthe
3rrate 3rchanges 3rin 3rresponse 3rto 3rthe 3rmetabolic 3rdemands 3rof 3rthe 3rbody
3r(Weber 3r& 3rKelley, 3r2010).
The 3relectrical 3rimpulses 3rinitiated 3rby 3rthe 3rSA 3rnode 3rare 3rcon- 3rducted 3ralong
3rthe 3rmyocardial 3rcells 3rof 3rthe 3ratria 3rvia 3rspecial- 3rized 3rtracts 3rcalled 3rinternodal
3rpathways. 3rThe 3rimpulses 3rcause
3r(L. 3r657)
L., 3rHinkle, 3rJ., 3rCheever, 3rH.. 3rBrunner 3r& 3rSuddarth's 3rTextbook 3rof 3rMedical-
Surgical 3rNursing, 3r13th 3rEdition. 3rLippincott 3rWilliams 3r& 3rWilkins, 3r12/2013.
3rVitalBook 3rfile.
What's 3rthe 3rfunction 3rof 3rcardiac 3rconduction 3rsystem? 3r- 3rANSWERS--generates
3rand 3rtransmits 3relectrical 3rimpulses 3rthat 3rstimulate 3rcontraction 3rof 3rthe 3rmyo-
3rcardium.
Conduction 3rsystem 3rkeeps 3rthings 3rin 3rorder. 3r
Under 3rnormal 3rcircumstances, 3rthe 3rconduction 3rsys- 3rtem 3rfirst 3rstimulates
3rcontraction 3rof 3rthe 3ratria 3rand 3rthen 3rthe 3rventricles.
