Systole

Definition

Systole is the phase of the cardiac cycle where the heart muscle contracts, pumping blood out of the chambers. It primarily involves the contraction of the ventricles.

5 Must Know Facts For Your Next Test

1. Systole is followed by diastole, which is the phase when the heart muscle relaxes and fills with blood.
2. During systole, pressure in the ventricles increases significantly to propel blood into the arteries.
3. The first heart sound (S1) is associated with systole and is produced by the closure of the atrioventricular (AV) valves.
4. Systolic blood pressure measures the force exerted on arterial walls during ventricular contraction.
5. Pharmacological agents such as beta-blockers can affect systolic function by reducing heart rate and contractility.

Review Questions

• What occurs during systole in terms of heart muscle activity?
• How does systolic pressure differ from diastolic pressure?
• Which heart sound is associated with systole and what causes it?

Related terms

Diastole:

The phase of the cardiac cycle where the heart muscles relax and chambers fill with blood.

Ventricular Contraction: The process during which ventricles contract to pump blood out of the heart.

Atrioventricular Valves: Valves located between atria and ventricles that close during systole to prevent backflow.