The Conducting System & Heart

What is #1

SA Node

What is #2

AV Node

What is #3

AV Bundle, Bundle of His

What is #4

Purkinje fibers

What is #5

Interventricular Septum

What is #6

Left bundle branch

What is #7

Interatrial Septum

Conduction Pathway

SA Node → Atria → AV Node → Bundle of His → Right and Left Bundle Branches → Purkinje Fibers

Epicardium

outermost layer of heart

Myocardium

Cardiac Muscle, responsible for pumping action of heart

Endocardium

Inner most layer

The cardiac cycle

the period between the start of one heartbeat and the beginning of the next

Systole

Contraction of a chamber

Diastole

Relaxation of a chamber

Phases of the cardiac cycle

Atrial systole → atrial diastole → ventricular systole → Ventricular diastole

Ausculation

listening to heart sound via stethescope

S1

“lub” caused by the closing of the AV valves

S2

“dub” caused by the closing of the semilunar valves

S3

a faint sound associated with blood flowing into the ventricles

S4

faint sound associated with atrial contraction

Heart Murmur

abnormal sound consisting of a clicking, rushing, or gurgling sound heard before, between, or after normal heartbeat

Equipment Needed to take pulse

Inflatable Cuff & Pump, Pressure Gauge, Stethoscope, sphygmomanometer

Locations to take Pulse

1) Wrist: Radial Pulse
2) Neck: Carotid Pulse
3) Inner Elbow: Brachial Pulse

What creates a pulse

The artery walls expanding and contracting as blood flows through