Lab 8- Cardiac Anatomy Flashcards
What is the function of intercalated discs?
Type of gap junction
Heart wall
- Epicardium (visceral pericardium)
- Myocardium (muscle)
- Endocardium (facing ventricles)
Describe the position of the valves when the ventricles re relaxed and when they are contracted.
Relaxed- AV valved open, semilunar are closed
Contracted- Semilunar open, AV are closed
Systole
Contraction
-atrial systole happens first
Diastole
relaxation
Cardiac cycle
P wave to P wave
-when the heart goes through full systole and diastole
S1 (lubb)
AV valves closing
S2 (dubb)
Semi lunar valves closing
How much time does one little box represent?
0.04s
Hw much time does one large box (5 little) represent?
0.20s
How many little boxes equal 1 second?
25 little boxes
What voltage is represented by one little box?
.10mV/small box
How many little boxes equal 1mV?
10
What do P waves represent?
Normal duration?
normal amplitude?
Cause of abnormalities?
atrial depolarization
- <0.12s
- 0.05 to 0.25mV
- mitral valve stenosis or pulmonary hypertension
What does the PQ segment represent?
between end of P start of Q