Autonomic Nervous System Regulation
4.1 Autonomic Nervous System Regulation Introduction
Open Resources for Nursing (Open RN)
Learning Objectives
- Identify the classifications and actions of autonomic nervous system drugs
- Give examples of when, how, and to whom autonomic nervous system drugs may be administered
- Identify the side effects and special considerations associated with autonomic nervous system drugs
- Include considerations and implications of using autonomic nervous system drugs across the lifespan
- Include evidence-based concepts when using the nursing process and clinical reasoning related to medications that affect the autonomic nervous system
Key Terms
Have you ever wondered what causes your heart to beat or your lungs to breathe? These are examples of involuntary responses the brain controls without the need for conscious thought. The autonomic nervous system (ANS) works using a balance of the sympathetic and parasympathetic nervous systems that regulate the body’s involuntary functions, including heart rate, respiratory rate, digestion, and sweating. Many medications are used to control various cardiovascular, respiratory, and gastrointestinal conditions by acting on ANS receptors. Beta-blockers and anticholinergic medications are the most commonly prescribed medications in this category.
Binds to both nicotinic receptors and muscarinic receptors in the PNS.
The response when the SNS is stimulated causing the main effects of increased heart rate; increased blood pressure; and bronchodilation.
Also called muscarinic agonists. Primarily cause smooth muscle contraction, resulting in decreased HR, bronchoconstriction, increased GI/GU tone, and pupil constriction.
Postganglionic neuron where neurotransmitters norepinephrine and epinephrine are released. Includes alpha (α) receptors and beta (β) receptors.
The breakdown of glycogen into glucose, causing elevated blood sugar.
An anatomical division of the nervous system that is largely outside the cranial and vertebral cavities, namely all parts except the brain and spinal cord.
Mimic the effects of the body’s natural SNS stimulation on alpha (α) and beta (β) receptors. Also called sympathomimetics.
The process by which the body temporarily seals a ruptured blood vessel and prevents further loss of blood.
Postganglionic neurons of the autonomic system are classified as either cholinergic, meaning that acetylcholine (ACh) is released, or adrenergic, meaning that norepinephrine is released.
Block the effects of the SNS receptors.
Elevated blood sugar.
All preganglionic neurons (in the SNS and PNS) release acetylcholine (ACh).
Inhibit acetylcholine (ACh) which allows the SNS to dominate. Also called parasympatholytics or muscarinic antagonists. Overall use is to relax smooth muscle.
Stimulation causes increased force of contraction.
Medications that mostly inhibit B1 receptors.
Controls cardiac and smooth muscle, as well as glandular tissue; associated with involuntary responses.
Responses that the brain controls without the need for conscious thought.
Sense the environment and conduct signals to the brain that become a conscious perception of that stimulus.
Include norepinephrine, epinephrine and dopamine. Stimulate the adrenergic receptors.
Consist of the somatic nervous system that stimulates voluntary movement of muscles, and the autonomic nervous system that controls involuntary responses.
Mnemonic for the effects of anticholinergics: Salivation decreased; Lacrimation decreased; Urinary retention; Drowsiness/dizziness; GI upset; Eyes (blurred vision/dry eyes).
Anatomical division of the nervous system located within the cranial and vertebral cavities, namely the brain and spinal cord.
Also called parasympathomimetics. Primarily cause smooth muscle contraction, resulting in decreased HR, bronchoconstriction, increased GI/GU tone, and pupil constriction.
Causes contraction of skeletal muscles; associated with voluntary responses.
Postganglionic neuron where acetylcholine (ACh) is released that stimulates nicotinic receptors and muscarinic receptors. Also relating to drugs that inhibit, enhance, or mimic the action of ACh.
Cells that carry electrical impulses to the synapse of a target organ.
Associated with the “fight or flight response.” Stimulation causes the main effects of increased heart rate, increased blood pressure via the constriction of blood vessels, and bronchodilation.
Drugs may change the heart rate and rhythm by affecting the electrical conduction system of the heart and the nerves that influence it, such as by changing the rhythm (increasing) produced by the sinoatrial node. Positive chronotropes increase heart rate; negative chronotropes decrease heart rate.
Medications that block both Beta 1 and Beta 2 receptors, thus affecting both the heart and lungs.
Mimic the effects of the body’s natural SNS stimulation of adrenergic receptors. Also called adrenergic agonists.
