2.2 EKG Flashcards
What are the two circulatory circuits? Their functions?
pulmonary and systemic
*same function: gas exchange
What need a change in WHAT to get flow? What affects flow rate?
need a change in pressure
*resistance affects flow rate
What happens to two vessels if they have the same change in pressure?
the vessels will still be EQUAL
what are the 3 main things that affect resistance?
1) viscosity
2) vessel length
3) vessel diameter
viscosity
measure of friction between molecules of a flowing fluid
vessel length means more? were?
more frictional resistance
*along vessel wall
What is most important factor affecting resistance? Why?
diameter because we can change it; causes exponential change
What is renals #?
how turbulent blood flow is
*greater the #, greater the turbulence
symphathetic release? affect what area of the heart? increase or decreaste rate?
release norepinephrine
- affect all of heart
- ***increase heart rate
parasymphathetic release? affect what area of the heart? increase or decreaste rate?
release acetylcholine
- right vegas affects SA and R atrium
- left vegas affects AV node and L atrium
- *** decrease heart rate
sequence of excitation?
SA node atrial internodle pathway AV node bundle of His (R and L) purkingje fibers
what are important ions for heart?
Na. K. Cl. Ca
What is the normal resting potential for ventricular muscle? for SA node?
vent muscle = -90
SA node= -60 to -70
What is pacemaker of heart? why?
SA node; has a lower threshold to meet = pre-potential
what does positive and negative chronotrophic effect mean?
\+ = SPEED up; norepinephrine, sym - = SLOW down, acetylcholine, parasym
what does decreasing a delay mean? examples?
to speed something up
- sym speeds up rate and decreases delay
- para slows rate and increases delay
vector always points to?
the NEGATIVE, aka area that hasn’t been depolarized
where does ventricular and atrial repolarization happen?
ven= T artrial= R
What happens are P?
- atrial depolarization
- repolarization obscured by ventricular depolarization
What happens are Q?
- ventricular depolarization
- generally base to apex, but a minor initial negative deflection
What happens are R?
- depolarization continues (BULK of it)
- base to apex
- positive deflection
- -repolarization of atrials
What happens are S?
-negative deflection at final instant of depolarization
What happens are T?
- repolarization of ventricles
- apex to base
- positive deflection
repolarization is mainly repsresented by?
T, bulk is +
describe 1st, 2nd, and 3rd degree blocks?
1- prolonged PR
2- two or more P waves before QRS
3- equidistant QRS, ventricles stimulate themselvesbc no impulse from SA reaches them
What does a double peaked R mean?
bundle branch block, independent depolarization of both ventricels
3 most common types of premature beats?
1) atrial
2) AV node
3) premature ventricular contraction
atrial premature beats?
originate from ectopic focus in atrium, abnormal P wave
AV node premature beats?
originate from ectopic focus in AV node, giving an EARLY QRS before P
premature ventricular contraction
from ecotpic focus in ventricular muscle, gives an early and Wide QRS (before P)
flutter vs fibrillation?
flutter= rapid COORDINATED REGULAR contractions; caused by ONE ectopic foci fibrilation= rapid UNcoordinated IRREGULAR contractions; caused by MANY ectopic foci
atrial flutter
caused by actopic focus in atrium
many P waves and occasional QRS
ventricular flutter
ectopic focus in ventricle
*SINE WAVES, severly impacts pumping
atrial fibrilation
MANY ectopic foci in atrium at different rates
*See QRS and then chaos, no P wave
ventricular fibrillation
MANY ectopic foci in ventircle at different rates
*NO WAVES AT ALL, complete squiggles
what is cardiac arrest?
a type of ventricular fibrillation
*need CRP (cardiopulmonary resuscitation)
What are the components of CRP?
1) cardiac massage -maintain blood to brain
2) artificial respiration- oxygenate blood
