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chp 14 define terms

  • Adrenergic Receptors

    • Adrenergic receptors are G protein-coupled receptors that mediate the effects of catecholamines like adrenaline and noradrenaline. They are categorized into alpha (α) and beta (β) receptors, each with subtypes (α1, α2, β1, β2, β3) that have different roles in the body.

    Beta Blockers

    • Beta blockers, also known as beta-adrenergic antagonists, are medications that block the effects of catecholamines primarily at the beta receptors. They are commonly used to treat hypertension, anxiety, heart failure, and certain types of arrhythmias. They reduce heart rate and contractility, leading to decreased myocardial oxygen demand.

    Cholinergic Receptors

    • Cholinergic receptors respond to the neurotransmitter acetylcholine. They are classified into nicotinic and muscarinic receptors. Nicotinic receptors are primarily found at the neuromuscular junction and in the autonomic ganglia, while muscarinic receptors are found at the target organs of the parasympathetic nervous system.

    Hypertension

    • Hypertension, or high blood pressure, is a chronic condition that can lead to serious health complications, including heart disease, stroke, and kidney damage. It is often treated with lifestyle changes and medications, including beta blockers, ACE inhibitors, and diuretics, to help manage blood pressure levels.

    Neostigmine

    • Neostigmine is an acetylcholinesterase inhibitor that increases the levels of acetylcholine in the synaptic cleft by inhibiting its breakdown. It is primarily used in the management of myasthenia gravis and to counteract the effects of certain muscle relaxants after surgery.

    Parasympathetic System

    • The parasympathetic nervous system is a division of the autonomic nervous system responsible for promoting rest-and-digest activities. It conserves energy by slowing heart rate, increasing intestinal and gland activity, and relaxing sphincter muscles in the gastrointestinal tract.

    Raynaud’s Phenomenon

    • Raynaud’s phenomenon is a condition characterized by episodes of vasospasm in response to stress or cold, leading to discoloration of the fingers and toes. It occurs due to excessive vasoconstriction and is often secondary to other conditions like autoimmune disorders.

    Sympathetic System

    • The sympathetic nervous system is another division of the autonomic nervous system, which prepares the body for 'fight-or-flight' responses. It increases heart rate, dilates air passages, and inhibits digestion, mobilizing energy reserves for quick action during stressful situations.

    Tricyclic Antidepressants

    • Tricyclic antidepressants (TCAs) are a class of medications used to treat major depressive disorder and other mood disorders. They work by inhibiting the reuptake of neurotransmitters like serotonin and norepinephrine, increasing their availability in the brain. They have a range of side effects, including sedation, weight gain, and anticholinergic effects.