cardio 2 Flashcards
2 types of pace cells
pacemaker cells
conduction cells
pacemaker cells
they generate x spontaneously
APs
both the SA node and the AV node can generate a
pace
SA vs AV nide: whichever has a x pace sets the pace
whichever is faster
conduction fibers spread throughout the
heart
conduction fibers also produce APs spontaneously but..
at a slower rate
APs spread through X disks
intercalcated dirks with gap junctions
-this allows the AP to spread uniformly rather than one cell at a time
order of AP:
1. An action potential is initiated in the X node and travels by way of
X fibers to the X node. Action potential spreads throughout
the cells of the atria.
2. Impulse arrives at the X node where there is slight X because action potentials are transmitted more slowly in these
cells than in other cells of the conduction system. This also allows time
for atria contraction to occur (i.e., fill ventricles before they fire)
3. Impulse leaves the X node and travels through the XX X in the interventricular septum.
4. XX X only travels a short distance before splitting into right and left bundle branches.
5. Impulse travels to the X cells of the X by means of an extensive network of conduction fibers called X fibers.
. An action potential is initiated in theSA nodeand travels by way of
conduction fibers to theAV node. Action potential spreads throughout
the cells of the atria.
2. Impulse arrives at theAV nodewhere there is a momentary
delaybecause action potentials are transmitted more slowly in these
cells than in other cells of the conduction system. This also allows time
for atria contraction to occur (i.e., fill ventricles before they fire)
3. Impulse leaves the AV node and travels through theatrioventricular
bundle(bundle of His) in theinterventricular septum.
4. Atrioventricular bundles only travels a short distance before splitting
into right and left bundle branches.
5. Impulse travels to the myocardial cells of the ventricle by means of an
extensive network of conduction fibers calledPurkinje fibers.
ECG:
leads roughly form a triangle w the X at the center
- recording at X degree angle
with the heart at the center
at a 60 degree angle
white to the X, (of the patient), X over fire (on the left)
Lead 2 : reference electrode is at the
right X limb, recording electrode
is at the left X limb,
reference at R upper limb
recording is at L lower limb
The combination of a reference and
recording electrode is called a
Lead
Einthoven’s triangle
It is a theoretical triangle formed by the three standard limb leads used in ECGs to record the heart’s electrical activity:
Lead I: Measures the voltage between the right arm (RA) and the left arm (LA).
Lead II: Measures the voltage between the right arm (RA) and the left leg (LL).
Lead III: Measures the voltage between the left arm (LA) and the left leg (LL).
the lead flow is…
neg to pos
traveling down is X deflection
- X from lead II
traveling down = + deflection
- away from lead II
traveling up is X deflection
- X lead II
traveling up = - deflection
- towards lead II
LV pressure and and volume is an X system. It is not need a signal from the neuron. It contracts based of stretch, not neuron signal.
intrinsic system
S1 is from
S1 sound is from the closure of the mitral AND tricuspid valve
S2 is from
S2 sound is from the closure of the aortic AND pulmonic valve
S3 is from
S3 sound is from the inflow of blood into the ventricles during diastole
S4 is from
S4 sound is from the vibration of ventricular wall, during contraction of the atrium
