The Cardiovascular System

The Cardiovascular SystemHeart Actions

Heart soundsCardiac MuscleCardiac Conduction systemECG

Normal for humans 60-100 bpmHeartbeatSystole = contraction

Diastole = filling/relaxation

Bradycardia (slow) vs. tachycardia (fast)

Atrial Systole/ventricular Diastole

Atrial Diastole/Ventricular SystoleLub

If you listen to your heartbeat, it makes a lub dub sound.The lub is when blood is pushed out of the heart into the body and the dub is the reloading of the heart with more blood ready to push it out to the bodyDub

4Heart SoundsLub = S1Ventricular systoleAV valves closing

Dub = S2Ventricular diastoleSemilunar valves closingHeart Murmur = Sound of flowGrades 1-6, 1-3 are soft sounds, 4,5,6 are very loudInnocent or normal sounds louder with feverEasier to hear in children (less fat and muscle)Could mean a valve problem or hole in heartHear all sorts of different heart sounds:

http://depts.washington.edu/physdx/heart/demo.html

Latin for to listen listen to internal body sounds.Places to Auscultate

Cardiac Muscle functional synctium

Intercellular junctions allow diffusion of ions and make impulse travel rapidly between cellsOnly 1 per cell (skeletal muscle is multinucleated)Cells beat togetherCardiac Muscle

Skeletal MuscleSmooth MuscleCardiac Conduction System

SA (sinoatrial) Node

SA (sinoatrial) node:Pacemaker of the heartUses Ca,/Na ions to conduct impulse Sets rate at 70-80 bpm

AV (atrioventricular) node:Keeps synctium

Impulse starts at apex and moves superiorlyPacemakers

ECGBody fluids conduct electric currents

Polarization separated ions, at rest Depolarized = cations flood cell, causes nerve impulse

Arrhythmias

Ventricular fibrillation chaotic contraction, no blood pumped BAD

Cause: obstructed coronary artery, drugs, electric shock, traumatic injury

Treat: defibrilate (AEDs)

Normal 75 bpm100-200 bpm

Bradycardia -