NSG-2233-01 (23/FA): Pharmacology/Metrology Lilley et al. (2020) 18, 19

Acrocyanosis

Decreased amount of oxygen delivered to the extremities, causing the feet or hands to turn blue.

Adrenergic receptors

Specific receptor sites located throughout the body for the endogenous sympathetic neurotransmitters norepinephrine and epinephrine.

Agonists

Drugs with a specific receptor affinity that mimic the body's natural chemicals (e.g., hormones, neurotransmitters).

Angina

Paroxysmal (sudden) chest pain caused by myocardial ischemia.

Antagonists

Drugs that bind to specific receptors and inhibit or block the response of the receptors.

Dysrhythmias

Irregular heart rhythms; generally called arrhythmias in clinical practice.

Extravasation

The leaking of fluid from a blood vessel into the surrounding tissues, as in the case of an infiltrated intravenous infusion.

First-dose phenomenon

Severe and sudden drop in blood pressure after the administration of the first dose of an alpha-adrenergic blocker.

Intrinsic sympathomimetic activity

The paradoxical action of some beta-blocking drugs (e.g., acebutolol) that mimics the action of the sympathetic nervous system.

Lipophilicity

The chemical attraction of a substance (e.g., drug molecule) to lipid or fat molecules.

Orthostatic hypotension

A sudden drop in blood pressure when a person stands up. Also referred to as postural hypotension or orthostasis.

Pheochromocytoma

A vascular adrenal gland tumor that is usually benign but secretes epinephrine and norepinephrine and thus often causes central nervous system stimulation and substantial blood pressure elevation.

Raynaud's disease

A narrowing of small arteries that limits the amount of blood circulation to the extremities, causing numbness of the nose, fingers, toes, and ears in response to cold temperatures or stress.

Sympatholytics

Drugs that inhibit the postganglionic functioning of the sympathetic nervous system.

Adrenergic agonists

Drugs that stimulate and mimic the actions of the sympathetic nervous system. Also called sympathomimetics.

Adrenergic receptors

Receptor sites for the sympathetic neurotransmitters norepinephrine and epinephrine.

Alpha-adrenergic receptors

A class of adrenergic receptors that are further subdivided into alpha1- and alpha2-adrenergic receptors.

Autonomic functions

Bodily functions that are involuntary and result from the physiologic activity of the autonomic nervous system. The functions often occur in pairs of opposing actions between the sympathetic and parasympathetic divisions of the autonomic nervous system.

Autonomic nervous system

A branch of the peripheral nervous system that controls autonomic bodily functions. It consists of the sympathetic nervous system and the parasympathetic nervous system.

Beta-adrenergic receptors

Receptors located on postsynaptic cells that are stimulated by specific autonomic nerve fibers. Beta1-adrenergic receptors are located primarily in the heart, whereas beta2-adrenergic receptors are located in the smooth muscle fibers of the bronchioles, arterioles, and visceral organs.

Catecholamines

Substances that can produce a sympathomimetic response. They are either endogenous catecholamines (such as epinephrine, norepinephrine, and dopamine) or synthetic catecholamine drugs (such as dobutamine).

Dopaminergic receptor

A third type of adrenergic receptor (in addition to alpha-adrenergic and beta-adrenergic receptors) located in various tissues and organs and activated by the binding of the neurotransmitter dopamine, which can be either endogenous or a synthetic drug form.

Mydriasis

Pupillary dilation, whether natural (physiologic) or drug induced.

Ophthalmics

Drugs that are used in the eye.

Positive chronotropic effect

An increase in heart rate.

Positive dromotropic effect

An increase in the conduction of cardiac electrical impulses through the atrioventricular node, which results in the transfer of nerve action potentials from the atria to the ventricles. This ultimately leads to a systolic heartbeat (ventricular contractions).

Positive inotropic effect

An increase in the force of contraction of the heart muscle (myocardium).

Sympathomimetics

Drugs used therapeutically that mimic the catecholamines epinephrine, norepinephrine, and dopamine. Also called adrenergic agonists.

Synaptic cleft

The space either between two adjacent nerve cell membranes or between a nerve cell membrane and an effector organ cell membrane (also called synapse).