Chapter 46: Physiology of the Autonomic and Central Nervous Systems and Indications for the Use of Drug Therapy

What does the body create using choline? a. Acetylcholine b. Tyramine c. Dopamine d. Cholesterol

a. Acetylcholine The nerves that produce acetylcholine use choline from the diet to produce the neurotransmitter.

The anatomy and physiology instructor is discussing adrenergic receptors with the nursing class. What adrenergic receptor would the instructor tell the students is found in the heart and can stimulate increased myocardial activity and increase heart rate? a. Alpha1 b. Alpha2 c. Beta1 d. Beta2

c. Beta1 Beta1 receptors are found in cardiac tissue where they can stimulate increased myocardial activity and increased heart rate. Alpha1 receptors are found in blood vessels, in the iris, and in the urinary bladder. Alpha2 receptors are located on nerve membranes and act as modulators of norepinephrine release. Beta2 receptors are found in smooth muscle in blood vessels, in the bronchi, in the periphery, and in uterine muscle.

The physiology instructor explains to the nursing students that stimulation of what leads to vasodilation of blood vessels? a. Alpha1 stimulation b. Alpha2 stimulation c. Beta1 stimulation d. Beta2 stimulation

d. Beta2 stimulation In blood vessels, beta-2 stimulation leads to vasodilation.

Norepinephrine is the main neurotransmitter in the sympathetic nervous system. Which enzyme metabolizes norepinephrine? a. Adenylyl cyclase b. Effector enzyme c. Choline acetyltransferase d. Monoamine oxidase

d. Monoamine oxidase Following its release from adrenergic nerve endings, most of the norepinephrine that does not return to the nerve endings is either absorbed by the surrounding tissue or metabolized by monoamine oxidase (MAO) or catechol-O-methyltransferase (COMT).

The nurse administers a drug that stimulates beta2 receptors. What type of health condition would this drug treat? a. heart disease b. high lipid levels c. diabetes d. respiratory disease

d. respiratory disease Beta2-receptors are found in the smooth muscle in blood vessels, in the bronchi, in the periphery, and in uterine muscle. Beta2-receptors also cause dilation in the bronchi. Beta1-receptor stimulation would improve some heart disease and are responsible for increased lipolysis. Because beta2-receptors increase release of glucagon and the breakdown of glycogen, increasing serum glucose levels, stimulation of these receptors would exacerbate diabetes.

Which reaction results from the stimulation of nicotinic receptors? a. Muscle contraction b. Muscle relaxation c. Vasodilation d. Vasocontraction

a. Muscle contraction Nicotinic receptors are located at neuromuscular junctions in skeletal muscle. Their activation causes muscle contraction.

A client has begun to experience post-operative pain and the client's heart rate has increased from 72 beats per minute to 96 beats per minute. The nurse should attribute this change to the effect of: a. stimulation of beta1 receptors in the sympathetic nervous system. b. reuptake of norepinephrine in synapses of the sympathetic nervous system. c. stimulation of muscarinic receptors in the parasympathetic nervous system. d. conversion of norepinephrine to dopamine in synapses of the sympathetic nervous system.

a. stimulation of beta1 receptors in the sympathetic nervous system. Stimulation of beta1 receptors increases heart rate. Reuptake of norepinephrine limits the sympathetic response. Stimulation of muscarinic receptors would cause a decrease in heart rate. Dopamine is converted to norepinephrine in the SNS; norepinephrine is not converted to dopamine.

The nurse accompanies the healthcare provider into the client's room and remains after the client is told that they have cancer and a poor prognosis. The client's respirations become rapid and deep, their pupils dilate, and they appear diaphoretic. What type of response is the nurse witnessing? a. sympathetic nervous system (SNS) response b. parasympathetic nervous system (PNS) response c. muscarinic receptor stimulation response d. nicotinic receptor stimulation response

a. sympathetic nervous system (SNS) response When stimulated, the SNS prepares the body to flee or to turn and fight. Cardiovascular activity increases, as do blood pressure, heart rate, and blood flow to the skeletal muscles. Respiratory efficiency also increases; bronchi dilate to allow more air to enter with each breath, and the respiratory rate increases. Pupils dilate to permit more light to enter the eye to improve vision in darkened areas. PNS would lower heart rate and blood pressure and would constrict pupils. The client's response could not be wholly isolated to a muscarinic or nicotinic response.

Stimulation of the sympathetic nervous system results in all of the following EXCEPT: a. Increased arterial blood pressure and cardiac output. b. Decreased rate of cellular metabolism. c. Increased breakdown of muscle glycogen for energy. d. Increased rate of blood coagulation.

b. Decreased rate of cellular metabolism. Stimulation of the sympathetic nervous system results in all of the following: increased arterial blood pressure and cardiac output; increased rate of cellular metabolism: increased oxygen consumption and carbon dioxide production; increased breakdown of muscle glycogen for energy; and increased rate of blood coagulation.

Cholinergic receptors are classified as nicotinic or muscarinic. What is a result of the stimulation of the nicotinic receptors? a. Increased GI motility b. Decrease in heart rate c. Muscle contraction d. Pupil constriction

c. Muscle contraction Nicotinic receptors are located in the CNS, the adrenal medulla, the autonomic ganglia, and the neuromuscular junction. Stimulation of nicotinic receptors causes muscle contractions, autonomic responses, and release of norepinephrine from the adrenal medulla. Increased GI motility, decreased heart rate, and pupil constriction are the result of stimulation of muscarinic receptors.

Parasympathetic stimulation causes the release of nitrous oxide from the endothelium of blood vessels. Which of the following results from this release? a. Increased inflammation b. Increased platelet aggregation c. Relaxation of vascular smooth muscle d. Constriction of blood vessels

c. Relaxation of vascular smooth muscle The release of nitrous oxide from the endothelium results in decreased platelet aggregation, decreased inflammation, relaxation of vascular smooth muscle, and dilation of blood vessels.

What statement best explains the central and peripheral nervous system? a. Structures of the central nervous system include the brain, neurons, and ganglia. b. The central nervous system (CNS) can be broken down into the somatic and autonomic pathways. c. The two main divisions that control the nervous system are the central and peripheral nervous system. d. Structures of the peripheral nervous system include the hypothalamus, brain stem, and spinal column.

c. The two main divisions that control the nervous system are the central and peripheral nervous system. The nervous system has two main divisions: the central nervous system and the peripheral nervous system. The CNS includes the brain and spinal cord, while the PNS includes the neurons and ganglia around outside the CNS. The efferent portion of the PNS has two subdivisions: the somatic and autonomic nervous system.

Which would NOT occur when nicotinic receptors are stimulated? (Mark all that apply.) a. Muscle contractions b. Release of norepinephrine from the adrenal medulla c. Signs and symptoms of a stress reaction d. Signs and symptoms of a rest and digest reaction e. Muscle relaxation

d. Signs and symptoms of a rest and digest reaction e. Muscle relaxation Stimulation of nicotinic receptors causes muscle contractions, autonomic responses such as signs and symptoms of a stress reaction, and release of norepinephrine and epinephrine from the adrenal medulla.

The sensory nerves enter the brain and react with related nerves to cause a reaction. What mediates this reaction? a. muscles or glands b. limbic system c. cerebral cortex d. neurotransmitters

a. muscles or glands The sensory nerves that enter the brain react with related motor nerves to cause a reaction mediated by muscles or glands. The motor impulses that leave the cortex are further regulated or coordinated by the pyramidal system, which coordinates voluntary movement, and the extrapyramidal system, which coordinates unconscious motor activity that regulates control of position and posture. Therefore, the other options are incorrect.

What helps to prevent overstimulation of effector sites on nerve membranes? a. Alpha1-receptors b. Alpha2-receptors c. Beta1-receptors d. Beta2-receptors

b. Alpha2-receptors Alpha2-receptors are located on nerve membranes and act as modulators of norepinephrine release. When norepinephrine is released from a nerve ending, it crosses the synaptic cleft to react with its specific receptor site. Some of it also flows back to react with the alpha-receptor on the nerve membrane. This causes a reflex decrease in norepinephrine release. In this way, the Alpha2-receptors help to prevent overstimulation of effector sites.

Neurons communicate through the use of synapses. These synapses may link neurons into functional circuits. How do the neurons communicate through the synapses? a. Electrically b. Excitatorily c. Chemically d. Inhibitorily

c. Chemically Norepinephrine, a neurotransmitter, belongs to a group of structurally related chemicals called catecholamines that also includes dopamine, serotonin, and epinephrine. Neurons do not communicate electrically, excitatorily, or inhibitorily.

Which client is most directly exhibiting the function of afferent nerves? a. A client who has winced with pain during an intramuscular injection b. A client who admits to having intense preoperative anxiety c. A client who is lifting a weight during physical therapy d. A client who has developed personality changes and memory loss following a traumatic brain injury

a. A client who has winced with pain during an intramuscular injection The perception of pain involves afferent nerves because physical stimulus from a sensory nerve is being transmitted to the CNS where it is perceived as pain. Voluntary muscle movements depend on a signal being transmitted from the CNS to the skeletal muscles via efferent nerves. Anxiety, personality, and memory do not directly involve this communication between the periphery and the CNS.

A client's nerve has been stimulated by pain and the resulting electrical action potential has reached the end of the axon. What will happen next? a. A neurotransmitter will be released into the synaptic cleft b. The signal will cross the synaptic cleft and continue via a new neuron c. The signal will revert back to the neuronal cell body d. The adjacent nerve will be electrically stimulated

a. A neurotransmitter will be released into the synaptic cleft When the electrical action potential reaches the end of an axon, the electrical impulse comes to a halt. The transmission of information between two nerves or between a nerve and a gland or muscle is chemical. The nerve axon, called the presynaptic nerve, releases a chemical called a neurotransmitter into the synaptic cleft, and the neurotransmitter reacts with a very specific receptor site on the postsynaptic cell to cause a reaction. The signal does not revert back to the cell body.

Nicotinic receptors would be found in which location? a. Adrenal medulla b. Sweat glands c. Bladder d. Gastrointestinal tract

a. Adrenal medulla Nicotinic receptors are found in the CNS, the adrenal medulla, the autonomic ganglia, and the neuromuscular junction. Muscarinic receptors are found in the sweat glands, bladder and GI tract.

Nerve fibers secreting norepinephrine are called: a. Adrenergic b. Ganglia c. Ligand d. Afferent

a. Adrenergic Norepinephrine is released at most postganglionic fibers of the sympathetic nervous system. Nerve fibers secreting norepinephrine are called adrenergic fibers. Ligands are substances that bind to receptors. Afferent neurons carry sensory input from the periphery to the CNS and modify motor output through the action of reflex arcs. Ganglia are nerve cell clusters that house the cell bodies of the afferent nerves.

The nurse is assessing a client who has urinary hesitation and occasional overflow incontinence. What adrenergic receptors may be overstimulated in this client? a. Alpha-1 b. Alpha-2 c. Beta-1 d. Beta-2

a. Alpha-1 Alpha-1 receptors are found in blood vessels, the iris, and urinary bladder. Alpha-2 receptors are located on nerve membranes. Beta-1 receptors are found in cardiac tissue. Beta-2 receptors are found in the smooth muscle of the blood vessels, bronchi, in the periphery, and in uterine muscle.

The anatomy and physiology instructor is discussing adrenergic receptors with the nursing class. What adrenergic receptor would the instructor tell the students is found in the blood vessels, iris, and urinary bladder? a. Alpha1 b. Alpha2 c. Beta1 d. Beta2

a. Alpha1 Beta1 receptors are found in cardiac tissue where they can stimulate increased myocardial activity and increased heart rate. Alpha1 receptors are found in blood vessels, in the iris, and in the urinary bladder. Alpha2 receptors are located on nerve membranes and act as modulators of norepinephrine release. Beta2 receptors are found in smooth muscle in blood vessels, in the bronchi, in the periphery, and in uterine muscle.

The nurse administers a drug that causes vasoconstriction, contracted piloerection muscles, pupil dilation and urinary retention. What receptor is this drug most likely stimulating? a. Alpha1-receptors b. Alpha2-receptors c. Beta1-receptors d. Beta2-receptors

a. Alpha1-receptors Stimulation of alpha1-receptors results in vasoconstriction of blood vessels, increased peripheral resistance with increased blood pressure, contracted piloerection muscles, pupil dilation, thickened salivary secretions, and closure of the urinary bladder sphincter. None of the other receptors, when stimulated, would have this specific constellation of effects.

The nurse is caring for a client who is experiencing pain. The client describes the pain as "9" on a scale of 1 to 10, with 10 being the worst pain. What nursing interventions would be necessary for the nurse to implement? Select all that apply. a. Assess blood pressure. b. Count respirations. c. Use Glasgow coma scale. d. Check hemoglobin lab. e. Evaluate pupils.

a. Assess blood pressure. b. Count respirations. e. Evaluate pupils. The sympathetic nervous system (SNS) is stimulated by physical or emotional stress, such as strenuous exercise or work, pain, hemorrhage, intense emotions, and temperature extremes. The client is experiencing an increase in blood pressure, cardiac output, respiratory rate, blood glucose, muscle strength, and pupillary dilation to aid vision. The nurse should assess vitals including blood pressure, respiratory rate, and pupils. The Glasgow coma scale is not warranted at this time nor is checking laboratory values such as hemoglobin.

A client in distress has been given dobutamine, a medication intended to increase myocardial activity and heart rate. This medication likely stimulates what adrenergic receptor? a. Beta-1 b. Alpha-1 c. Alpha-2 d. Beta-2

a. Beta-1 Beta-1 stimulation increases myocardial activity. Alpha-1 stimulation leads to vasoconstriction and increased peripheral vascular resistance, resulting in a rise in blood pressure. Alpha-2 stimulation prevents overstimulation of effector sites and moderate insulin release by the beta cells of the pancreas. Beta-2 stimulation causes vasodilation and bronchodilation.

A client with asthma is prescribed albuterol to dilate the bronchioles. The nurse understands that this drug is likely acting on which receptors? a. Beta-2 b. Alpha-1 c. Alpha-2 d. Beta-1

a. Beta-2 Bronchodilation occurs with stimulation of beta-2 receptor sites. Vasoconstriction and increased peripheral vascular resistance occurs with alpha-1 receptor stimulation. Overstimulation of effector sites and moderate insulin release occurs with alpha-2 stimulation. Increased heart rate occurs with beta-1 receptor stimulation.

Which of the following effects might occur following the administration of a cholinergic drug? a. Decreased heart rate b. Pupil dilation c. Constriction of blood vessels in the skin d. Absorption of nitrous oxide by the endothelium of blood vessels

a. Decreased heart rate A cholinergic drug has the same effect on the body as stimulation of the parasympathetic nervous system. Effects of parasympathetic stimulation include decreased heart rate, pupil constriction, dilation of blood vessels in the skin, and release of nitrous oxide from the endothelium of blood vessels.

A client's left adrenal medulla has been injured in a motor vehicle accident. What is a possible implication of this injury? a. Disruptions in the levels of norepinephrine and epinephrine b. Dopamine deficiency c. Impaired action potential d. Disruption of the sodium-potassium pump

a. Disruptions in the levels of norepinephrine and epinephrine The adrenal medulla produces epinephrine and norepinephrine, but not dopamine. Impaired adrenal medullary functions would be unlikely to affect action potentials or the function of the sodium potassium pump throughout the nervous system.

A client has a diagnosis of Parkinson disease, a health problem that has effects on motor function and cognition. What neurotransmitter is most likely deficient in this client's CNS? a. Dopamine b. Norepinephrine c. Acetylcholine d. Gamma-aminobutyric acid (GABA)

a. Dopamine Dopamine levels are disrupted in Parkinson disease, as evidenced by the profound effects of motor function and cognition. Norepinephrine, acetylcholine and GABA do not have this combination of motor and cognitive functions.

The nurse is providing care for a client whose health history includes type 1 diabetes, peripheral vascular disease, environmental allergies and rheumatoid arthritis. The client is transitioning from living independently to living in a long-term care facility, which is causing the client intense stress. This stimulation of the client's sympathetic nervous system should prompt the nurse to prioritize what assessment? a. Frequent blood glucose monitoring b. Respiratory assessment and monitoring for shortness of breath c. Pain assessment d. Assessment of peripheral pulses

a. Frequent blood glucose monitoring Sympathetic stimulation causes release of glucagon and increase glycogenolysis, resulting in increased blood glucose. This could be problematic in a client with a history of diabetes, so the nurse should prioritize blood glucose monitoring. Sympathetic stimulation usually causes bronchodilation rather than shortness of breath or respiratory distress. There is no reason to believe the client's pain will be increased. There is unlikely to be any short-term change in the client's peripheral circulation.

After teaching a group of students about major divisions of the brain, the instructor determines that additional teaching is needed when the students identify what as part of the hindbrain? a. Hypothalamus b. Reticular activating system c. Swallowing center d. Respiratory control center

a. Hypothalamus The hypothalamus is part of the midbrain. The reticular activating system is part of the hindbrain. The swallowing center is part of the hindbrain. The respiratory control center is part of the hindbrain.

A nurse is reviewing the structure and function of the nervous system in preparation for working on a neurological floor. What characteristic of neurons should the nurse identify? a. Neurons convey action potentials to other neurons without being in physical contact. b. Dendrites are roughly equal in size to axons. c. Neurons are unique among body cells because they do not have a nucleus. d. The ability to generate new nerves after injury ceases near puberty.

a. Neurons convey action potentials to other neurons without being in physical contact. Nerve to nerve communication occurs across synaptic clefts; the two nerves that communicate to each other are not in physical contact. Neurons have nuclei and axons are sometimes exponentially longer than dendrites. New nerves cannot be produced.

The body uses tyrosine in the diet to make what substance? a. Norepinephrine b. Glutamate c. Estrogen d. Serotonin

a. Norepinephrine Norepinephrine is made by adrenergic nerves using tyrosine from the diet.

The nurse is caring for a client with asthma who has been experiencing shortness of breath and who has been administered a medication to cause bronchodilation. What aspect of autonomic nervous function has the nurse most likely influenced? a. Stimulation of beta-adrenergic receptors b. Reuptake of acetylcholine c. Synthesis of acetylcholinesterase d. Inhibition of alpha-adrenergic receptors

a. Stimulation of beta-adrenergic receptors Stimulation of beta receptors causes bronchodilation, which is the therapeutic effect of several medications for asthma. The bronchi are not primarily affected by the presence of acetylcholine receptors. Inhibiting the alpha adrenergic receptors does not cause bronchodilation.

The nurse assessed a client at 0800 and obtained a blood pressure of 111/70 mmHg. Two hours later, the client's blood pressure is 130/81 mmHg. The nurse should attribute this change to what action within the autonomic nervous system? a. Stimulation of beta-receptors b. Antagonism of alpha-receptors c. Decreasing levels of acetylcholinesterase d. Stimulation of nicotinic receptors

a. Stimulation of beta-receptors Increased blood pressure is among the effects of sympathetic nervous stimulation through activation of beta-receptors. Alpha receptors also affect blood pressure, but antagonism of these receptors would blood this hypertensive effect. Acetylcholine is involved in the physiology of the parasympathetic nervous system, which generally lowers blood pressure; low levels of acetylcholinesterase could plausible lower blood pressure by increasing the effects of acetylcholine on the parasympathetic receptors. Stimulation of nicotinic receptors is associated with reduced blood pressure.

A nurse is reviewing the structure and function of the neurologic system in preparation for a work placement on a neurologic unit. What statement most accurately describes an aspect of the autonomic nervous system? a. The autonomic nervous spans the central and peripheral nervous systems. b. Cholinergic receptors are exclusively located in the parasympathetic nervous system. c. Nicotinic receptors are primarily associated with the parasympathetic nervous system. d. Alpha- and beta-receptors are the two basic types of muscarinic receptors.

a. The autonomic nervous spans the central and peripheral nervous systems. The ANS integrates parts of the central nervous system (CNS) and peripheral nervous system to automatically react to changes in the internal and external environments. Stimulation of nicotinic receptors causes skeletal muscle contractions, autonomic responses such as signs and symptoms of a stress reaction, and release of norepinephrine and epinephrine from the adrenal medulla. These responses are primarily associated with the sympathetic nervous system. Alpha- and beta-receptors are not types of muscarinic receptors; they are classified as adrenergic receptors. Cholinergic receptors exist throughout various locations in the ANS, not just the parasympathetic nervous system.

The nurse is conducting an assessment of a newly admitted client. What assessment finding should suggest to the nurse that the client's muscarinic cholinergic receptors are being stimulated? a. The client has "pinpoint" pupils. b. The client's attention span is unusually short. c. The client's blood pressure is 119/72 mmHg. d. The client describes a frontal lobe headache.

a. The client has "pinpoint" pupils. Pupil constriction is among the effect of parasympathetic stimulation of muscarinic cholinergic receptors. Pain and cognition are not affected by these receptors. The client's blood pressure is well within acceptable ranges; there is no obvious indication of parasympathetic stimulation.

What assessment finding of a client should the nurse attribute to the stimulation of muscarinic receptors? a. The client is drooling. b. The client appears agitated. c. The client reports pruritis (itching). d. The client's respiratory rate is 20 breaths/min.

a. The client is drooling. Stimulation of muscarinic receptors causes increased saliva production. It is not associated with agitation or pruritis. A respiratory rate of 20 breaths/min is expected and is not suggestive of increased stimulation of any particular cholinergic receptor.

A client has been prescribed a medication that antagonizes the beta receptors of the sympathetic nervous system. What assessment finding should the nurse attribute to the effects of this medication? a. The client's blood pressure is decreased b. The client's nausea is relieved c. The client denies shortness of breath d. The client denies feeling anxious

a. The client's blood pressure is decreased Stimulation of beta receptors activates the renin-angiotensin-aldosterone system, which increases blood pressure. Conversely, blocking beta receptors causes a decrease in blood pressure. Nausea and anxiety are not normally affected. Stimulation of beta receptors causes bronchodilation, which can relieve shortness of breath.

The nurse is assessing a client. What assessment finding is the clearest indicator of autonomic function? a. The client's respiratory rate is 22 breaths per minute b. The client's hearing is intact c. The client's muscle strength is equal bilaterally d. The client can discern hot sensation from cold

a. The client's respiratory rate is 22 breaths per minute The autonomic nervous system functions to regulate respirations. Voluntary motor function, hearing and sensation are not primarily within the ANS.

What is the defining criterion of an adrenergic nerve? a. The nerve can produce epinephrine b. The nerve promotes cardiac conduction c. The nerve arises from the adrenal medulla d. The nurse is continuously stimulated

a. The nerve can produce epinephrine To be an adrenergic nerve, the nerve must contain all of the enzymes and building blocks necessary to produce norepinephrine and epinephrine. None of the other listed characteristics is associated with adrenergic nerves.

Which client's nicotinic receptors are likely being stimulated the most? a. a client who is anxious while waiting in the preoperative area b. a client who is taking medications for the treatment of Parkinson disease c. a client taking a selective serotonin reuptake inhibitor for depression d. a client who has increased bowel motility causing diarrhea

a. a client who is anxious while waiting in the preoperative area Stimulation of nicotinic receptors causes skeletal muscle contractions, autonomic responses such as signs and symptoms of a stress reaction, and release of norepinephrine and epinephrine from the adrenal medulla. These receptors do not respond to levels of dopamine or serotonin. Increased bowel motility is more closely associated with stimulation of muscarinic receptors.

Sympathetic stimulation of the heart causes: a. an increased rate and force of myocardial contraction. b. an excitatory response that stimulates the brain to generalized decreased activity. c. a decreased rate and force of myocardial contraction. d. decreased blood flow and impaired digestion.

a. an increased rate and force of myocardial contraction. Stimulation of the ANS causes excitatory effects in some organs but inhibitory effects in others. For example, sympathetic stimulation of the heart causes an increased rate and force of myocardial contraction; parasympathetic stimulation decreases rate and force of contraction, thereby resting the heart.

The up-regulation of receptors is responsible for what client reaction? a. anaphylactic shock triggered by a bee sting b. nausea caused by an adverse smell c. low blood pressure in response to severe diarrhea d. difficulty breathing triggered by bacterial pneumonia

a. anaphylactic shock triggered by a bee sting Up-regulation occurs when receptors, as a result of chronic exposure to substances that block their function, increase in number and become more efficient. Allergy related to bee stings is a hypersensitization reaction and the best example. None of the other examples result from up-regulation.

After teaching a group of students about the functions of the nervous system, the instructor determines that the teaching was effective when the students identify that a function is: a. control of body functions. b. generation of incoming stimuli. c. separation of responses. d. prevention of stimulus exposure.

a. control of body functions. The nervous system is responsible for controlling body function, analyzing incoming stimuli, and integrating internal and external responses.

The nurse is providing care for a client who has a health condition marked by excessive levels of acetylcholinesterase. The nurse should attribute assessment findings of this client to: a. low levels of acetylcholine. b. excess acetylcholine. c. overstimulation of alpha receptors in the SNS. d. agonism of muscarinic receptors.

a. low levels of acetylcholine. Excessive acetylcholinesterase would be linked to low levels of acetylcholine, since this enzyme terminates the action of acetylcholine. Alpha receptors respond to epinephrine and norepinephrine. Muscarinic receptors respond to acetylcholine, but would be understimulated rather than agonized if acetylcholine levels were excessive.

A nurse is caring for a client who has excessive salivation. Which muscarinic receptor is responsible for activation of the salivary glands? a. muscarinic1 b. muscarinic2 c. muscarinic3 d. muscarinic4

a. muscarinic1 Muscarinic1 receptor is expressed primarily in the central nervous system (CNS), autonomic ganglia, and the gastric and salivary glands. Muscarinic2 inhibits adenylyl cyclase in the heart, smooth muscle, and brain. Muscarinic3 is expressed in the CNS, smooth muscle, glands, and heart. Muscarinic4 inhibits acetylcholine release in the stratum and contributes to the development of Parkinson's disease. Muscarinic5 dilates cerebral arteries and arterioles and facilitates dopamine release.

The nurse is providing an overview of the structure and function of the nervous system to a client with a new diagnosis of multiple sclerosis. The nurse describes how a stimulus normally travels down the axon of a nerve and stimulates an effector cell by: a. releasing one or more neurotransmitters into the synapse. b. depolarizing the dendrite of the effector cell. c. stimulating the effector's dendrite that touches the nerve's axon. d. chemically stimulating the effector cells' Schwann cells.

a. releasing one or more neurotransmitters into the synapse. Electrical communication of a nerve signal ends at terminus of the axon, which does not physically touch the dendrite of the effector cell. Instead, chemical transmission takes place by the release of neurotransmitters into the synapse. The effector's dendrite is stimulated chemically, not electrically. Nerve to nerve transmission does not involve the role of Schwann cells.

Neurotransmission is important in the function of the CNS. For neurotransmission to occur, how do neurons communicate with other cells? a. Selectively b. Chemically c. Excitably d. Accessibly

b. Chemically The transmission of information between two nerves or between a nerve and a gland or muscle is chemical.

A patient with Parkinson's disease is being cared for on your unit. The nurse would be correct in identifying what neurotransmitter as being decreased in this disease? a. Acetylcholine b. Dopamine c. Neurontin d. Serotonin

b. Dopamine Parkinson's disease develops from decreased availability of dopamine, while acetylcholine binding to muscle cells is impaired in myasthenia gravis. Therefore options A, C, and D are incorrect.

Which statements are correct regarding the autonomic nervous system (ANS) receptors? Select all that apply. a. ANS drugs affect only specific organs and not the whole body. b. Drug effects depend on the branch of the ANS involved. c. Medications can either stimulate or inhibit the ANS. d. The nurse does not need to know about the receptors in the ANS. e. There are no drugs that affect the ANS or receptors.

b. Drug effects depend on the branch of the ANS involved. c. Medications can either stimulate or inhibit the ANS. Because ANS receptors are widespread throughout the body, drug that acts on the ANS usually affects the entire body rather than certain organs and tissues. Drugs effects depend on which branch of the ANS is involved and whether it is stimulated or inhibited by drug therapy. Knowledge of the physiology of the ANS is required by the nurse if drug therapy is administered.

What is the resulting physiologic effect when the parasympathetic nervous system is stimulated? a. Decreased GI secretions b. Increased GI motility c. Increased heart rate d. Pupil dilation

b. Increased GI motility When the parasympathetic nervous system is stimulated, the result is increased GI motility, decreased GI secretions, decreased heart rate, and pupillary constriction, which all result from stimulation of the sympathetic nervous system.

The anatomy and physiology instructor is discussing the role of neurotransmitters in the autonomic nervous system. Which would the instructor identify as the main adrenergic neurotransmitter? a. Epinephrine b. Norepinephrine c. Dopamine d. Acetylcholine

b. Norepinephrine Adrenergic refers to the sympathetic nervous system. The main neurotransmitter of the sympathetic nervous system is norepinephrine.

The anatomy and physiology instructor is discussing neurotransmitters with the pre-nursing A&P class. What would the instructor tell the students is a catecholamine that is classed as a hormone when it is released from the adrenal medulla? a. Ephedrine b. Norepinephrine c. Dopamine d. Acetylcholine

b. Norepinephrine Norepinephrine and epinephrine are catecholamines, which are released by nerves in the sympathetic branch of the autonomic nervous system and are classified as hormones when they are released from cells in the adrenal medulla.

Which of the following events is initiated when a ligand stimulates a receptor on target tissue? a. Release of a neurotransmitter b. Signal transduction c. Deactivation of a cell membrane-bound G protein d. Activation of the first messenger

b. Signal transduction When a receptor located on target tissue is stimulated by a ligand, a cascade of intracellular events collectively known as signal transduction is initiated. These intracellular events include the activation of a membrane-bound G protein and effector enzyme and the resulting activation of the second messenger. The ligand that stimulates the receptor is also referred to as the first messenger. A neurotransmitter, hormone, or drug can act as a ligand.

A client's nerves have been stimulated and the signal has reached the axon. How will communication continue? a. through the production of an electrical signal b. by the release of a neurotransmitter c. by physically stimulating the nerve on the other side of the synapse d. The nerve signal will cease at this point.

b. by the release of a neurotransmitter The transmission of information between two nerves or between a nerve and a gland or muscle is chemical, achieved by the release of a neurotransmitter. Communication is not electrical or physical, and communication does not necessarily cease at the axon.

The nurse administers a medication that stimulates the muscarinic receptors. What manifestations should the nurse expect to assess in this client? a. pupil dilation b. increased activity of bowel sounds c. increased heart rate d. muscle contractions

b. increased activity of bowel sounds Stimulation of muscarinic receptors increases gastrointestinal (GI) motility which would cause increased activity of bowel sounds. Other effects include pupil constriction, increased urinary bladder contraction, and a slowing of the heart rate. Stimulation of nicotinic receptors causes muscle contractions.

Characteristics that allow neurons to communicate with other body cells include: a. the ability to regulate body temperature. b. the ability to be stimulated and to convey electrical impulses. c. relaying motor impulses from the cortex to the thalamus. d. stimulation of "association areas" to analyze information received.

b. the ability to be stimulated and to convey electrical impulses. Neurons communicate at structures called synapses in a process called synaptic transmission. The synapse consists of the two neurons, one of which is sending information to the other. The sending neuron is known as the presynaptic neuron (ie, before the synapse), whereas the receiving neuron is known as the postsynaptic neuron (ie, after the synapse). Although the flow of information around the brain is achieved by electrical activity, communication between neurons is a chemical process.

Which effect results from activation of beta2 receptors? a. Pupil constriction b. Bronchoconstriction c. Bronchodilation d. Decreased heart rate

c. Bronchodilation Activation of beta2 receptors results in bronchodilation.

After the effector cell has been stimulated by acetylcholine (ACh), what enzyme stops this stimulation and allows the effector membrane to repolarize? a. decarboxylase b. norepinephrine c. acetylcholinesterase d. catecholamine

c. acetylcholinesterase After the effector cell has been stimulated by ACh, stimulation of the receptor site must be terminated and destruction of any ACh must occur. The destruction of ACh is carried out by the enzyme acetylcholinesterase. This enzyme reacts with the ACh to form a chemically inactive compound. The breakdown of the released ACh is accomplished in 1/1,000 second, and the receptor is vacated, allowing the effector membrane to repolarize and be ready for the next stimulation. Dopa decarboxylase is an enzyme that converts dopa to dopamine. Norepinephrine is a catecholamine as are dopamine, serotonin, and epinephrine.

A nurse is caring for a patient who is having a sympathetic response. A sympathetic response involves: a. a decrease in sweating, decrease in respirations, and pupil constriction. b. a decrease in heart rate, decrease in blood flow to skeletal muscles, and increase in inflammatory reactions. c. an increase in blood pressure, bronchi dilation, and decreased bowel sounds d. increased motility, secretions in the GI tract, and constriction of bronchi and pupils

c. an increase in blood pressure, bronchi dilation, and decreased bowel sounds Increase in blood pressure, bronchi dilation, and decreased bowel sounds are responses to sympathetic stimulation. Decrease in sweating, respirations, heart rate, and blood flow to skeletal muscles and increase in motility and secretions of GI tract and inflammatory reactions, and pupil and bronchi constrictions indicate parasympathetic stimulation.

A client is receiving pancuronium for induction of anesthesia prior to a surgical procedure. What outcome does the nurse identify the client will have during the surgical procedure from this medication? a. Less surgical complications b. Easier arousal from anesthesia c. A deeper level of sleep d. Paralyzed skeletal muscles

d. Paralyzed skeletal muscles Neuromuscular-blocking medications such as pancuronium, which act selectively at nicotinic receptors, can paralyze skeletal muscles in patients when limiting movement is therapeutic (such as in the ventilated patient or during surgery), without adversely affecting the other functions of the ANS. There are no less surgical complications from the use of pancuronium as with any other forms of anesthesia chosen for the individual client. The drug paralyzes skeletal muscles but does not induce or maintain sedation levels.