Systole

Systole is the last stage of a heart beat. It happens right after diastole, when the heart refills with blood. During systole, the heart's two ventricles contract (squeeze).^[1] (The ventricles are the largest parts of the heart, which pump blood to the body and lungs.)

During systole, the heart muscle gets an automatic electrical signal that tells the heart to contract (squeeze). This makes the blood flow out of the heart.

1. ↑ February 10, 2011. "Systole definition - Medical Dictionary definitions of popular medical terms easily defined on MedTerms". Medterms.com. Archived from the original on 2011-07-14. Retrieved 2011-02-10.{{cite web}}: CS1 maint: numeric names: authors list (link)