Ans 205

Front 1

Every cardiac cycle is ____ for every species

Back 1

Different

Front 2

Conduction system of heart

Back 2

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)

Front 3

One leave point

Back 3

Above SA node --> L. Side

Front 4

SA Node

Back 4

(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

Front 5

AV Node

Back 5

(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

Front 6

Bundle of His

Back 6

(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)

Front 7

Purkinje fibers

Back 7

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

Front 8

Wave of depolarization

Back 8

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

Front 9

Cardiac Cycle

Back 9

each complete cycle of contraction and relaxation of the heart

Two parts- systole and diastole

Front 10

Syn

Back 10

coming together (contraction)

Front 11

Dia

Back 11

Coming apart (relaxation)

Front 12

First step of Cardiac Cycle

Back 12

(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

Front 13

Ejection Fraction

Back 13

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

Typically 60-70% of total volume

Front 14

Second Step of Cardiac Cycle

Back 14

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

Semi-lunar valves only open up during ventricle systole

Front 15

Lub

Back 15

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

Front 16

Dub/Dupp

Back 16

second sound, semi-lunar valves closing, S2

Front 17

Measuring ventricuar systole and diastole

Back 17

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

Ventricular and atrial diastole overlap

Front 18

(EDV) End-Diastolic Volume

Back 18

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

135 mL

Front 19

Isovolumic Ventricular contraction

Back 19

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

Front 20

Ventricular Ejection

Back 20

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

Front 21

(ESV) End-Systolic Volume

Back 21

Min amount of blood in ventricles

65 mL

Front 22

Isovolumic Ventricular Relaxation

Back 22

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

Front 23

Cardiac murmurs

Back 23

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

Front 24

Murmur Insufficiency

Back 24

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

Front 25

Murmur stenosis

Back 25

creates whoosing sound, fails to open completely, creates restriction

Front 26

Murmur grading

Back 26

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

can live up to three

Four or five req. surgeries

Front 27

Electrocardiogram

Back 27

(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

Front 28

QRS

Back 28

masks atrial repolarization, corresponds to ventricular depolarization

Front 29

P wave

Back 29

corresponds to depolarization of SA node

Front 30

T wave

Back 30

corresponds to ventricular repolarization

Front 31

Arrythmia

Back 31

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

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

Front 32

AV Block

Back 32

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

Front 33

Arrythmia involving accessory pathways

Back 33

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

Front 34

Arrythmia involving ectopic pacemakers

Back 34

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

Front 35

Artierial blood pressure

Back 35

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)

Front 36

What regulates Blood Pressure

Back 36

neural reflexes- arterial baroreceptor reflexes

Humoral Agents- Angiotensin and aldosterone

Paracrine Agents- Nitric oxide and endothelin

Front 37

Auscultation

Back 37

to listen or hear