Two types of cardiac cells - correct answer The myocardial working cells and specialized pacemaker cells
Contraction - correct answer
... [Show More] Depolarization
Relaxation - correct answer Re-polarization
Most abundant chemicals in body - correct answer Extracellular: Sodium (Na+)
Intracellular: Potassium (K+)
Hypertrophy - correct answer Enlargement of muscle
SA Node - correct answer -Pacemaker of the heart
-Firing Rate= 60 to 100 beats per minute
-Depolarization and myocardial contraction occurs after impulse leaves SA Node.
-Located int he upper posterior portion of the right atrial wall of the heart. (Junction of RA and SVC)
Primary cardiac cell characteristics - correct answer 1. Automaticity
2. Excitability
3. Conductivity
4. Contractility
Electrolyte - correct answer substance or compound whose molecules dissociate into charged components or ions. Na+, Ca++, K+
+charged ions= cation
-charged ions= anion
Isoelectric - correct answer re-polarization line
Syncytium - correct answer cardiac muscle cell groups that are connected together and function as a unit. (all or nothing response)
Refractory Periods - correct answer Attempts to ensure muscle is totally relaxed before another action potential or depolarization can be initiated.
Atrial muscle= .15 sec
Ventricular muscle= .25 to .3 sec
Cardiac Repolarization - correct answer Referred to as "period of rest."
Threshold - correct answer point at which a stimulus will produce a cell response
Absolute Refractory Period - correct answer cardiac cell unable to respond to new electrical stimulus, cannot spontaneously depolarize. Starts at beginning of "Q" wave and ends in the middle of "T" wave.
Relative Refractory Period - correct answer Repolarization is almost complete, cardiac cell can be stimulated to contract prematurely if stimulus is stronger than normal. Starts at middle of "T" and ends at the end of "T" wave.
Internodal Pathways - correct answer -Receives the electrical impulse as it exits the SA Node. ( Anterior, Posterior, and Middle pathways)
-Pathways distribute impulse throughout atria.
-Transmits impulse from SA Node to AV Node
Bachmann's Bundle - correct answer -Group of interatrial fibers contained in left atrium
-a subdivision of anterior internodal tract
-Conducts electrical activity from the SA Node to the left atrium.
Atrioventricular (AV) Node - correct answer -Located on floor of right atrium above tricuspid valve.
-Electrical activity delayed 0.05 seconds
-Allows for more complete filling of ventricles
-only pathway for atrial electrical impulses to reach ventricles. ( Gate-Keeper to the ventricles)
AV Junction - correct answer - Where the SA Node joins Bundle of His
-SA Node fails or slows below normal, AV junctional tissues initiate electrical activity
- Secondary (Escape) Pacemaker- discharges at 40-60 beats per minute.
Bundle of His - correct answer -Conduction pathway that leads out of AV Node
-referred to as the "Common Bundle"
-Makes electrical connection between atria and ventricles
Bundle Branches - correct answer Two main Bundle Branches:
1.Right Bundle Branch
-long and thin
-Extends to apex of right ventricle
2.Left Bundle Branch
-Anterior and posterior fascicles
-Conduct electrical activity from Bundle of His to Purkinje Network.
Purkinje's Network - correct answer -Fibers that spread throughout the ventricles
-Carries impulses directly to ventricular muscle cells.
-Intrinsic firing rate of 20 to 40 beats per min.
Hyperkalemia - correct answer peaked "T" waves
Electrocardiogram - correct answer the graphic representation of the electrical activity of the heart
Electrocardiograph - correct answer Machine used to record the electrocardiogram, or EKG machine
EKG - correct answer a graphic tracing of electrical activity of the heart, not mechanical activity.
Oscilloscope - correct answer EKG monitor screen.
Rhythm strip or EKG strip - correct answer the printed record of the electrical activity of the heart
MCL - correct answer Modified chest leads (Bipolar)
Single lead electrocardiography - correct answer -for dysrythmia recognition.
-rate and regularity(rhythm)
Electrodes - correct answer -an adhesive pad that contains conductive gel and attaches to patient's skin
-gel reduces water surface layer of skin
Leads - correct answer what electrodes are connected to the cardiac monitor by.
-3 leads (wires) must have a positive(Red), a negative(White), and a ground(black).
Block - correct answer Block of electricity
Bipolar leads - correct answer leads have one negative and one positive electrode
Limb leads - correct answer leads I,II,and III
-lead II is most commonly used monitoring lead due to ability to visualize "P" waves and "QRS" waveforms
-Lead I = Left arm + and right arm -
-Lead II = Left leg + and right arm -
-Lead III = Left leg + and left arm -
Einthovens's triangle - correct answer imaginary inverted triangle formed around heart by proper placement of bipolar leads.
Positive Deflection - correct answer Electricity goes from - to + [Show Less]