Lesson 4.2 The Heart at Work - Key Terms Flashcards
Atrioventricular Node
A specialized mass of conducting cells located at the atrioventricular junction in the heart.
Blood Pressure
Pressure exerted by the blood upon the walls of the blood vessels, especially arteries, usually measured by means of a sphygmomanometer and expressed in millimeters of mercury.
Cardiology
The study of the heart and its action and diseases.
Diastole
The stage of the heart cycle in which the heart muscle is relaxed, allowing the chambers to fill with blood.
Diastolic Pressure
Blood pressure that remains between heart contractions.
Electrocardiogram (EKG)
A measurement of heart electrical activity.
Heart Rate
A measure of cardiac activity usually expressed as the number of beats per minute.
Hypertension
An abnormally high blood pressure.
Pacemaker
An electrical device for stimulating or steadying the heartbeat or reestablishing the rhythm of an arrested heart.
Pulse
The rhythmic expansion and recoil of arteries resulting from heart contraction; can be felt from the outside of the body.
Sinoatrial Node
A small mass of tissue that is made up of Purkinje fibers, ganglion cells, and nerve fibers, that is embedded in the musculature of the right atrium, and that originates the impulses stimulating the heartbeat – called also S-A node, sinus node.
Sphygmomanometer
An instrument for measuring blood pressure and especially arterial blood pressure.
Systole
The stage of the heart cycle in which the heart muscle contracts and the chambers pump blood.
Systolic Pressure
The pressure generated by the left ventricle during systole.
