heart lab and EKG

describe the shape of cardiac muscle cells

Y shape, intercalated discs, intertwined with other fibers, sends electricity in coordinated way through the heart, one to two nuclei

function of intercalated discs

electrical continuity

proteins that create the striated appearance in cardiac muscle cells

actin and myosin

what functions do cardiac muscle tissue perform?

contrat to pump blood

which division of the nervous system controls cardiac muscle tissue

autonomic

equation for heart rate from EKG

#R-R Intervals/# of seconds * 60sec/1min

normal heart rate

60-90 bpm (ideally 72)

what would a shortened R-R interval indicate?

higher heart rate

PR interval

P wave

QT interval

T wave

PQ segment

QRS complex

ST segment

R-R interval

Einthoven’s triangule

An imaginary inverted triangle formed by three specific electrodes placed on the body (Right Arm, Left Arm, Left Leg) that helps clinicians understand the direction of electrical currents in the heart.

P wave represents

atrial depolarization

QRS complex represents

ventricular depolarization

T wave represents

ventricular repolarization

PR interval

time it takes for an electrical signal to travel from atria to ventricles

QT interval

duration of ventricular systole, including contraction and recharge

PQ segment

delay at the AV node

ST segment

interval between the end of ventricular depolarization and the beginning of ventricular repolarization

pulse pressure equation

PP=SP-DP

mean arterial pressure equation

MAP=DP+PP/3

mean arterial pressure second equation

MAP=CO*TPR