Term
| absolute refractory period (ARP) |
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Definition
| the time during which the cardiac cell cannot depolarize regardless of the strength of the stimulus |
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Definition
| a neurotransmitter that slows down the rate of the heart by decreasing SA node automaticity |
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Definition
| receptors located on peripheral vasculature (skin, subcutaneous tissue, mucous membranes), GI tract, kidneys, etc.; causes arteriolar vasoconstriction when stimulated |
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Definition
| receptors located on the pre-synapatic terminal of the neuron that releases norepinephrine; when stimulated by the release of norepinephrine (or drugs that mimic norepinephrine), these receptors shut down further release of norepinephrine, providing a sedative effect on the animal |
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Definition
| the main artery of the body that carries oxygenated blood away from the heart and into systemic circulation |
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Definition
| the semilunar valve that lies between the left ventricle and the aorta; controls the flow of blood from the left ventricle out to the body (systemic circulation) |
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Term
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Definition
| abnormal rhythm of the heart caused by disrupted electrical activity |
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Term
| atrial-ventricular node (AV node) |
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Definition
| receives the wave of depolarization from the SA node to depolarize the ventricles |
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Term
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Definition
| the ability of a cell to depolarize spontaneously |
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Definition
| receptors located on the SA node, AV node, and cardiac muscle; increase heart rate and force of contraction |
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Definition
| receptors located on the bronchioles of the lungs and blood vessels of the skeletal muscles; causes bronchodilation and vasodilation to assist in fight or flight |
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Definition
| the pacemaker of the ventricles when the depolarization wave from the SA node can't reach the ventricles |
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Definition
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Definition
| drugs that block acetylcholine receptors and increase heart rate |
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Term
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Definition
| receptors that bind to acetylcholine to slow the rate of the heart by slowing conduction of the depolarization wave from atria to ventricles |
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Definition
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Term
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Definition
| occurs by sodium channels opening to allow an influx of sodium ions across the cell membrane of polarized cells; this removes the charged "poles" of the cell membrane |
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Term
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Definition
| the movement of ions out of a cell |
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Term
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Definition
| allow sodium ions to quickly influx by following their concentration gradient |
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Term
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Definition
| an arrhythmia that occurs when the chambers of the heart are not contracting in a coordinated manner |
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Term
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Definition
| the movement of ions into a cell |
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Term
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Definition
| the chamber of the heart that receives oxygenated blood from the lungs (pulmonary circulation) |
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Term
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Definition
| the chamber of the heart that pumps oxygenated blood out to the body (systemic circulation) |
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Term
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Definition
| the left atrioventricular (AV) valve that lies between the left atrium and left ventricle and has 2 cusps (bicuspid) |
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Term
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Definition
| the effective concentrations of a drug are very close to concentrations that produce toxicity |
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Term
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Definition
| represents depolarization of the atria on an ECG |
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Term
| parasympathetic nervous system (PSNS) |
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Definition
| the component of the autonomic nervous system that regulates functions related to rest and restoration |
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Term
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Definition
| rapid sodium influx via fast channels, interior of the cell is very positively charged |
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Term
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Definition
| potassium channels open, interior of cell becomes less positive/more negatively charged |
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Term
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Definition
| influx of calcium ions keeps the charge on the interior cell membrane more positive despite potassium leaving the cell |
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Term
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Definition
| calcium channels close while potassium ions continue to efflux out of the cell |
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Term
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Definition
| resting phase, base line; the cell will remain in this phase until stimulated again |
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Term
| pulmonic (pulmonary) valve |
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Definition
| a semilunar valve that lies between the right ventricle and the pulmonary artery; controls the flow of deoxygenated blood to the lungs for reoxygenation |
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Term
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Definition
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Term
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Definition
| large wave on an ECG that represents depolarization of the ventricles |
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Term
| relative refractory period |
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Definition
| the time during which the cardiac cell may depolarize if sufficient stimulus is provided |
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Term
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Definition
| occurs when sodium channels shut and potassim channels open, allowing potassium ions out of the cell and re-establishing poles across the cell membrane |
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Term
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Definition
| the chamber of the heart where deoxygenated blood returns from the body (systemic circulation) |
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Term
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Definition
| the chamber of the heart that pumps deoxygenated blood to the lungs (pulmonary circulation) for reoxygenation |
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Term
| sinoatrial node (SA node) |
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Definition
| known as the "pacemaker" of the heart because it depolarizes spontaneously and more frequently that any other cell in the heart |
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Term
| sodium-potassium-ATPase pump |
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Definition
| the enzyme responsible for pumping sodium ions out of the cell and potassium ions into the cell |
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Term
| sympathetic nervous system |
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Definition
| the component of the autonomic nervous system that regulates functions related to fight or flight |
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Term
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Definition
| represents ventricular repolarization on an ECG |
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Term
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Definition
| the right atrioventricular (AV) valve that lies between the right atrium and right ventricle and has three cusps |
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Term
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Definition
| large veins that carry deoxygenated blood from the body into the right atrium of the heart |
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Term
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Definition
| an influx of sodium ions that causes adjacent sodium channels to also open up in a wave along the cell |
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Term
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Definition
| the flat period on an ECG that represents the delay between the depolarization of the atria and the depolarization of the ventricles; occurs when the depolarization wave is passing through the AV node to get to the ventricles |
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Term
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Definition
| drugs that block beta receptors to decrease heart rate |
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Term
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Definition
| receptors that bind to norepinephrine or epinephrine to increase heart rate and speed up conduction of the depolarization wave from atria to ventricles; also stimulates cardiac muscles to contract with greater force |
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