Lab: Circulatory System Flashcards
Define: pulse pressure (PP).
difference between the systolic and diastolic pressure; represents the change in arterial pressure between beats
PP = SBP - DBP
Mean arterial pressure (MAP).
avg. force exerted by the blood against the walls of the arteries during the entire cardiac cycle
MAP = DBP + 1/3 (SBP - DBP)
Where is Lead 1 placed during an EKG?
horizontal
left arm to right arm
Where is Lead 2 placed during an EKG?
diagonal
right arm to left leg
Where is Lead 3 placed during an EKG?
vertical
left arm to left leg
Describe the flow of electrical activity in the heart.
1) sinoatrial (SA) node (a.k.a. pacemaker)
2) left and right atria
3) atrioventricular (AV) node
4) atrioventricular (AV) bundle
5) left and right bundle branches
6) Purkinje fibers
7) left and right ventricles
Which extremity is grounded during an EKG?
right leg
Define: prehypertension.
systolic BP = 130-140
Define: hypotension.
BP = or < 90/60
Define: hypertension.
BP = or > 140/90
What makes the S1 heart sound?
AV valves closing
What makes the S2 heart sound?
SL valves closing
What is the normal blood pressure range?
110/70 - 120/80
What is the significance of the PR interval?
it represents one full atrial cycle
What is the significance of the QT interval?
it represents one full ventricular cycle
What is the significance of the PQ segment?
it represents the lag time between atrial depolarization and repolarization
What is the significance of the ST segment?
it represents the lag time between ventricular depolarization and ventricular repolarization
What is the formula for heart rate using an EKG?
HR = 1500 / # boxes in one cardiac cycle
1 box on an EKG corresponds to how much time?
0.04 seconds
What is the average length of a cardiac cycle?
0.8 seconds
