Cardiac Flashcards
1
Q
P wave
A
- Depolarization of the atria.
- Atria contract.
2
Q
QRS complex
A
- Repolarization of the atria and depolarization of the ventricles.
- Atria relax and ventricles contract.
3
Q
T wave
A
- Repolarization of the ventricles.
- Ventricles relax.
4
Q
U wave
A
- Tiny hump at the end of the T wave (2-part T wave).
- Repolarization of the papillary muscle.
5
Q
Atrial Systole
A
- Atria contract and ventricles relax.
- AV valves open and let blood into ventricles.
- Semilunar valves stay closed.
- Depolarization of the SA node = P wave
6
Q
Systole vs. Diastole
A
- Systole = Contraction
- Diastole = Relaxation
7
Q
1) What makes the systolic BP sound?
2) What makes the diastolic BP sound?
A
1) 1st sound. Contraction of the ventricles and vibrations of the closing AV valves.
2) 2nd, short, sharp sound. Vibrations of the closing SL valves.
8
Q
Isovolumetric Ventricular Contraction
A
- Ventricular volume remains constant as pressure increases rapidly.
- Occurs between the start of ventricular systole and the opening of the SL valves.
- Intraventricular pressure is high enough to close the AV valves, producing the 1st heart sound, but is not yet high enough to open the SL valves.
- Ventricular systole = R wave = SL valves open.
9
Q
Ejection
A
- Intraventricular pressure exceeds pressure in pulmonary artery and aorta.
- SL valves open and blood is ejected from ventricles.
- Rapid ejection = initial contraction
- Reduced ejection = less abrupt
10
Q
Isovolumetric Ventricular Relaxation
A
- Ventricular diastole begins.
- Occurs between closure of SL valves and opening of AV valves.
- Pressure decreases dramatically but not enough to open AV valves, so volume stays the same.
- 2nd heart sound heard when SL valves snap shut.
11
Q
Passive Ventricular Filling
A
- Falling intraventricular pressure and rising intraatrial pressure.
- Pressure gradient forces AV valves to open slightly and pushes blood through.
- At the end, a new P wave triggers contraction of the atria, and the whole thing starts over.
