Unformatted text preview: enable them to pump blood throughout the body. 3. A specific region of the heart muscle is the pacemaker. The pacemaker sets the rate at which your heart contracts. It generates electrical impulses that spread rapidly over the walls of both atria, making them contract. The impulses then spread to a region of the heart called the AV node. From there, the electrical impulses spread to the ventricles, causing them to contract. The contracting ventricles propel blood to the rest of the body. 4. Systolic pressure is the highest recorded pressure in an artery when the ventricles contract. Diastolic pressure is the lowers recorded pressure in an artery during the relaxation phase of the heartbeat....
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- Spring '09
- left atrium, Pulmonary valve, ight vent ricle, ight atrioventricular valve