Test 2/5/25 Patho Heart conduction

a composite recording of all the action potentials produced by nodes. cells and signals of the myocardium. each wave or segment corresponds to a certain event of the cardiac electrical cycle

P wave- when the atria fills with blood, the SA node fires the electrical signals spread throughout the atria causing them to depolarize.

PQ Segment- represents the time the signal travels from the SA node to the AV node.

QRS Complex- marks the firing of the AV node and represents ventricular depolarization.

R wave- depolarization of the main mass of the ventricles.

S wave- last phase of ventricular depolarization at the base of the heart. Atrial repolarization also occurs at this time but the signal is obscured by the large ORS complex

ST segment reflects the plateau in the myocardial action potential. When the ventricles contract and pump blood. 

T wave- represents ventricular repolarization

the cycle repeats itself with every heartbeat

Contractility the ability of the muscle cells to shorten/ contract

elasticity- the ability of the heart resuming its shape after being stretched

congestive heart failure leads to edema this means swelling caused by excess fluid in the tissues