Cardiovascular (Cardiac Cycle and Heart Sounds)

Cardiac Cycle describes the ____________ ___________ of contraction and relaxation of the heart.

repeating pattern

Systole descibes of phase of __________ of the ventricles

contraction

Contraction pumps blood ______

out

Diastole describes the phase of _________ of the ventricles

relaxation

Cardiac Cycle Mnemonic

A Squeeze Ejects, Relaxes, and Refills

Steps of Cardiac Cycle (5):

1. Atrial Contraction

2. Isometric Contraction

3. Ejection Phase

4. Isovolumetric Relaxation

5. Rapid Filling

1. Atrial Contraction

-Where in the Phase?
-Status of Valves

[LATE DIASTOLE]

-AV Valves: OPEN
-SL Valves: CLOSED

1. Atrial Contraction

[LATE DIASTOLE]

-Atria gives final push.
-Pushes remaining 20% of blood into Ventricle

2. Isometric Contraction

-Where in the Phase?
-Status of Valves

[EARLY SYSTOLE]

AV Valves: CLOSED
SL Valves: CLOSED

2. Isometric Contraction

[EARLY SYSTOLE]

-No blood flow into/out of ventricles

-Pressure high enough to squeeze

3. Ejection Phase

-Where in the Phase?
-Status of Valves

[MID-LATE SYSTOLE]

AV Valves: CLOSED
SL Valves: OPEN

3. Ejection Phase

[MID-LATE SYSTOLE]

- Pressure forces SL open
- Blood flow into Aorta and Pulmonary Trunk

4. Isometric Relaxation


-Where in the Phase?
-Status of Valves

[EARLY DISTOLE]

AV Valves: CLOSED
SL Valves: CLOSED

4. Isovolumetric Relaxation

[EARLY DISTOLE]

-No blood flow into/out of ventricles

5. Rapid Filling


-Where in the Phase?
-Status of Valves

[MID-LATE DIASTOLE]

AV Valves: OPEN
SL Valves: CLOSED

5. Rapid Filling

[MID-LATE DIASTOLE]

-Blood flows from Atria to Ventricle

When is the LUBB sound produced?

During Isovolumetric Contraction

[EARLY SYSTOLE]

Why is the LUBB sound produced?

Closing of AV Valve

When is the DUBB sound produced?

During Isovolumetric Relaxation

[EARLY DIASTOLE]

Why is the DUBB sound produced?

Closing of the SL Valve