Stress, Adrenergic Agonists and Cholinergic Therapy Flashcards

Flashcards on Stress, Adrenergic Agonists, and Cholinergic Therapy

General Adaptation Syndrome

Hans Selye's concept describing the body's response to stress in three phases: alarm, resistance, and exhaustion.

Alarm Stage

The initial stage of the General Adaptation Syndrome where the body reacts with 'fight or flight' and the adrenal glands release catecholamines.

Catecholamines

Hormones, such as epinephrine and norepinephrine, released by the adrenal glands during the alarm stage to combat stress and maintain homeostasis.

Resistance Stage

The second stage of the General Adaptation Syndrome, where the hypothalamus signals the pituitary to produce corticosteroids, and the body operates at peak performance.

HPA Axis

Hypothalamic-Pituitary-Adrenal Axis. Signaled during times of resistance by the hypothalamus.

Exhaustion Stage

The final stage of the General Adaptation Syndrome, where energy reserves are depleted, the immune system is compromised, and tolerance to stress decreases.

Gastric Stress Ulcers

Also known as Curling's ulcer or Cushing's ulcer, these are stress-related disorders affecting the gastrointestinal system.

Adrenergic Agonists

Drugs that mimic the actions of norepinephrine and epinephrine, working on the sympathetic nervous system to treat life-threatening conditions.

Alpha 1 Receptors

Adrenergic receptors located in blood vessels, eyes, bladder, and prostate, causing vasoconstriction.

Alpha 2 Receptors

Adrenergic receptors located in postganglionic sympathetic nerve endings that inhibit norepinephrine release, leading to vasodilation and decreased BP.

Beta 1 Receptors

Adrenergic receptors primarily in the heart and kidneys; stimulation increases myocardial contractility and heart rate.

Beta 2 Receptors

Adrenergic receptors found in smooth muscle of the lungs, GI tract, liver, and uterine muscle, causing bronchodilation, decreased GI tone/motility, glycogenolysis, and uterine relaxation.

Catecholamines (Drug Classification)

Adrenergic drugs that cannot be given orally, have a short duration of action, and do not cross the blood-brain barrier, e.g., Epinephrine.

Noncatecholamines

Adrenergic drugs that may be given orally, have a longer duration of action, and can cross the blood-brain barrier, e.g., Albuterol.

Epinephrine

A catecholamine primarily used in emergency medicine for severe allergic reactions; it increases cardiac output, promotes vasoconstriction/BP elevation, increases heart rate, and causes bronchodilation.

Albuterol

A noncatecholamine primarily used for the prevention and treatment of bronchospasm.

Cholinergic Drugs

Drugs that affect the parasympathetic nervous system (PNS) and mimic the neurotransmitter acetylcholine (ACH).

Nicotinic and Muscarinic Receptors

Two types of receptors that bind with ACH.

Cholinergic Agonist

A drug that stimulates the PNS directly or indirectly, either by binding to cholinergic receptors or inhibiting acetylcholinesterase.

Bethanechol

A cholinergic agonist that stimulates muscarinic receptors in the bladder and GI tract to increase bladder tone/GI motility and relax sphincters, and is used for post-op urinary retention.

Cholinergic Antagonist

A drug that inhibits the action of ACH by occupying muscarinic receptors, which in turn inhibits the PNS.

Atropine

A cholinergic antagonist that blocks vagus stimulation (increasing heart rate), paralyzes the iris sphincter (pupil dilation), and is used to decrease secretions, increase HR, and dilate pupils.