- action potential
- rapid depolarization of the cell (i.e., the cell membrane potential increasing or becoming more positive as compared to its surroundings) followed by repolarization (i.e., the cell membrane potential decreasing back to the resting voltage)
- afterload
- the amount of systemic pressure that the heart must overcome to eject blood during systole
- arteries
- blood vessels that carry oxygenated blood away from the heart and to the tissues for perfusion; singular, artery
- atria
- the two upper chambers of the heart; singular, atrium
- automaticity
- a process by which a spontaneous action potential forms, allowing a tissue to act as the pacemaker of the heart
- bundle of His
- part of the electrical system of the heart
- capillaries
- small blood vessels that run between arteries and veins and allow oxygen perfusion and nutrient exchange; singular, capillary
- cardiac output
- the amount of blood pumped from the left ventricle per unit of time
- contractility
- the strength of the force of left ventricular contraction
- depolarization
- a process by which a cell’s negative baseline resting membrane potential increases and becomes positive
- diastole
- the phase of the cardiac cycle in which a chamber is relaxing or filling
- dysrhythmias
- irregularities in the heart rate or rhythm; singular, dysrhythmia
- electrocardiography (EKG, ECG)
- a common diagnostic tool that allows health care professionals to monitor various aspects of a client’s heart including rate, rhythm, or the presence of ischemia.
- membrane potential
- the voltage (i.e., ionic charge) of a cell as compared to its surroundings
- preload
- the volume of blood that fills the left ventricle at the end of diastole
- pulmonary arteries
- the blood vessels that carry deoxygenated blood from the right ventricle to the lungs for gas exchange; singular, artery
- pulmonary veins
- blood vessels that carry oxygenated blood from the lungs back to the left atrium of the heart; singular, vein
- Purkinje fibers
- special muscle cells that allow coordinated contraction of the heart
- systemic vascular resistance
- the resistance to blood flow within the artery, determined by the arterial diameter
- systole
- the phase of the cardiac cycle in which a chamber is contracting or pumping
- veins
- blood vessels that carry deoxygenated blood back to the heart
- ventricle
- one of the two lower chambers of the heart
- waveforms
- the upward and downward deflection on an electrocardiogram