• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

Card Range To Study



Play button


Play button




Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

37 Cards in this Set

  • Front
  • Back

Every cardiac cycle is ____ for every species


Conduction system of heart

SA Node, Internodal pathways (specific), AV node ("Node of delay"), Bundle branches, Bundle of His, Purkinje fibers (myocardial cells without fibrous skeletons, contraction starts at apex)

One leave point

Above SA node --> L. Side

SA Node

(sinoatrial node) located in R. Atrium (near where vena cava enter), "Pacemaker of heart"- under control of the autonomic nervous system,

Specialized area of cardiac muscle cells that have the quality of automatically generating electrical impulses triggering repeated beating of heart

AV Node

(Atrioventricular Node), top of atrioventricular septum, specialized group of cardiac muscle cells, serve as auxiliary pacemakers, protect ventricles from beating too fast, only route of conduction from atria to ventricles

Bundle of His

(AV Bundle), travels down interventricular septum, 1st part- slow conduction of action potentials, creates a delay btwn atrial and ventricular contractions, R and L bundle branches (only route of conduction from atria to ventricles)

Purkinje fibers

AV bundle branches break into dispersed network of fibers, carry action potentials to into ventricular myocardium (apex upwards)

Wave of depolarization

SA node depolarizes --> Electrical activity goes rapidly to AV node via intermodal pathways --> depolarization spreads more slowly across atria, conduciton slows through AV node--> Depolarization moves rapidly through ventricular conducting system to the apex of the heart --> depolarization wave spreads upwards from apex

Cardiac Cycle

each complete cycle of contraction and relaxation of the heart

Two parts- systole and diastole


coming together (contraction)


Coming apart (relaxation)

First step of Cardiac Cycle

(passive ventricular filling, both sets of chambers relaxed) 70% filling of ventricles- AV valves open --> atria-systole fills up the last 30% --> AV valve shuts

Ejection Fraction

portion of total blood in ventricles that is pushed out in systole

Typically 60-70% of total volume

Second Step of Cardiac Cycle

(Ventricular Diastole) pressure decrease and blood starts to fall but semilunar valves catch it

Semi-lunar valves only open up during ventricle systole


first sound of heartbeat, closure of AV valves, S1, separated from Dub by a short interval and then followed by a longer pause


second sound, semi-lunar valves closing, S2

Measuring ventricuar systole and diastole

120/80, atria systole and diastole is too short (1/3 of ventricular)

Ventricular and atrial diastole overlap

(EDV) End-Diastolic Volume

the max. amount of blood in ventricles occurs at end of ventricle relaxation

135 mL

Isovolumic Ventricular contraction

first phase of ventricular contraction pushes AV valves closed, but not enough pressure to open semilunar valves

Ventricular Ejection

Ventricular pressure increases, greater pressure in arteries, semilunar valves open and blood ejected

(ESV) End-Systolic Volume

Min amount of blood in ventricles

65 mL

Isovolumic Ventricular Relaxation

Ventricular pressure decreases, blood --> cups of semilunar valves and they close

Cardiac murmurs

turbulent flow of blood due to any defect in valves, indicate the presence of cardiac abnormalities, can either by systolic or diastolic, mitral valve is normally the problem

Murmur Insufficiency

creates gurgling sound, allows regurgitation, valve fails to close completely

Murmur stenosis

creates whoosing sound, fails to open completely, creates restriction

Murmur grading

1 (not bad) --> 5 (very bad)

can live up to three

Four or five req. surgeries


(ECG) a recording of the electrical changes that occur in the myocardium during a cardiac cycle, noting electrical activity in walls of the heart

P + T wave w/QRS complex in middle


masks atrial repolarization, corresponds to ventricular depolarization

P wave

corresponds to depolarization of SA node

T wave

corresponds to ventricular repolarization


abnormal cardiac electrical activity (rate, rhythms, and propagation of action potential)

SA node fails to function normally (sinus bradycardia or tachycardia)

AV Block

impulses aren't conducted from the atria to the ventricles through the AV node, arrythmia

Arrythmia involving accessory pathways

abnormal conduction pathways are followed, ie accessory pathways between atria and ventricles

Arrythmia involving ectopic pacemakers

other pacemaker sites within the artia or ventricles (ectopic pacemakers) trigger depolarization

Artierial blood pressure

arterial pressure= CO (cardiac output) times TPR (total peripheral resistance)

Pressure in vessels depends on amount of blood in vessel (CO) and rate that it can leave (TPR)

What regulates Blood Pressure

neural reflexes- arterial baroreceptor reflexes

Humoral Agents- Angiotensin and aldosterone

Paracrine Agents- Nitric oxide and endothelin


to listen or hear