The cardiac cycle. Flashcards
How long does cardiac cycle take?
0.8 seconds.
How would you know that one complete cardiac cycle has occured?
There has been one complete contraction and relaxation of all four chambers of the heart.
Do both ventricles contract independantly or at the same time?
At the same time.
What are Desmosomes.
From desmos (greek), bond or chain. MACULA (spot) ADHERENS.
Gap junctions.
Connexons. Connect the cytoplasm of two cells.
Where is the electrical conduction of the heart slower than elewhere and what’s it’s significance?
The electrical conductance at the AVN is much slower than elsewhere to allow the ventricles to fill up with blood.
In an ECG what does the gap between the P wave and the QRS complex indicate?
That atrial depolarisation is complete.
In an ECG what does the QRS complex indicate?
Ventricular depolarisation.
What does the T wave indicate?
Ventricular repolarisation.
The peak at R indicates.
Commencement of Ventricular Systole.
Closure of the AV valve.
The first heart sound.
When is the second heart sound heard in tandem with the ECG.
Almost 2/3 in the T wave.
List the five phases of the cardiac cycle.
Passive filling of the Ventricles (most of the blood),
Active filling of the Ventricles by Atrial contraction,
Isovolumetric ventricular contraction,
Ventricular ejection,
Isovolumetric ventricular relaxation.
