Autonomic Nervous System PREPU

Which of the following effects results from activation of beta2 receptors?

Bronchodilation Activation of beta2 receptors results in bronchodilation.

In the sympathetic nervous system, which of the following is the origin of central nervous system nerves?

Thoracic spinal cord Rationale: The central nervous system nerve origin in the sympathetic nervous system is the thoracic and lumbar primal cord. Its origin in the parasympathetic nervous system is the cranium and sacral spinal cord.

Axons from the CNS neurons end in which of the following structures?

Ganglia Rationale: Axons from CNS neurons end in ganglia, or groups of nerve bodies that are packed together, located outside of the CNS.

A patient is using his incentive spirometer during the postoperative period. The skeletal muscles during the use of the incentive spirometer are stimulated by which neurotransmitter?

Acetylcholine Rationale: When acetylcholine acts on body cells that respond to parasympathetic nervous stimulation, it interacts with two types of cholinergic receptors: nicotinic and muscarinic. Nicotinic receptors are located in motor nerves and skeletal muscle. Dopamine is a catecholamine neurotransmitter that elevates blood pressure. Epinephrine is responsible for maintaining blood pressure. Norepinephrine is released to manage severe hypotension.

Nicotinic receptors would be found in which location?

Adrenal medulla Rationale: Nicotinic receptors are found in the adrenal medulla. Muscarinic receptors would be found in the sweat glands. Muscarinic receptors would be found in the bladder. Muscarinic receptors are found in the GI tract.

The sympathetic and the parasympathetic nervous systems are continuously at work in our bodies. This continual action provides a sense of balance to all parts of the body. What is the term used to represent this sense of balance?

Homeostasis Rationale: In many areas, the parasympathetic nervous system works in opposition to the SNS. This allows the autonomic system to maintain a fine control over internal homeostasis. For example, the SNS increases heart rate, while the parasympathetic system decreases it. Homeostasis is balance, it is not eustress, power, or strength.

The physiology instructor explains to the nursing students that Beta2 stimulation leads to which of the following?

Vasodilation of blood vessels Rationale: In blood vessels, Beta2 stimulation leads to vasodilation.

In which of the following areas are nicotinic receptors located? Select all that apply.

• Central nervous system (CNS) • Adrenal medulla • Neuromuscular junction • Autonomic ganglia Rationale: Nicotinic receptors are located in the CNS, the adrenal medulla, the autonomic ganglia, and the neuromuscular junction.

After teaching a group of students about catecholamines, the instructor determines a need for additional teaching when the students identify which of the following as an example?

Acetylcholine Rationale: Acetylcholine is a neurotransmitter that is not considered a catecholamine. Serotonin is a catecholamine. Dopamine is a catecholamine. Norepinephrine is a catecholamine.

Which neurotransmitter is involved in pre- and postganglionic activity in the parasympathetic nervous system?

Acetylcholine Rationale: In the PNS, the neurotransmitter involved in pre- and postganglion activity is acetylcholine. Norepinephrine is involved in postganglionic activity of the SNS. Epinephrine is involved in the adrenergic response, being secreted directly into the bloodstream by the adrenal medulla. Dopamine is converted to norepinephrine in the adrenergic cells.

A patient is admitted to the emergency room after a car accident. Based on the experience of the emergency room nurse, what system will affect a response to the emergency?

Autonomic nervous system Rationale: The functions of the autonomic nervous system can be described broadly as activities designed to maintain a constant internal environment (homeostasis), to respond to stress or emergencies, and to repair body tissues. The central nervous system regulates respiration or circulation. The endocrine system regulates hormone balance. The cardiovascular system regulates heart function.

Stimulation of which receptor results in increased myocardial activity during the stress response?

Beta-1 Rationale: 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 patient is receiving a drug that helps to dilate the bronchioles. The nurse understands that this drug is acting on which receptor site?

Beta-2 Rationale: 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.

Deactivation of norepinephrine (NE) occurs by breakdown of NE by which of the following enzymes?

COMT Rationale: Deactivation of NE occurs by breakdown of NE by the enzyme COMT or, most importantly, by reuptake into the presynaptic neuron, where it may be used or inactivated by another enzyme, monoamine oxidase (MOA).

Which type of cells synthesize and store norepinephrine and epinephrine?

Chromaffin Rationale: The chromaffin cells of the adrenal medulla synthesize, store, and release norepinephrine, as well as epinephrine.

Which of the following is a component of the body's sympathetic response?

Decreased bowel sounds Rationale: 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.

Stimulation of the sympathetic nervous system results in all of the following EXCEPT:

Decreased rate of cellular metabolism. Rationale: 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.

A client is experiencing a stress response. Which of the following would the nurse expect to assess?

Diminished bowel sounds Rationale: In the stress or fight-or-flight response, the nurse would assess diminished bowel sounds, tachycardia, hypertension, and pupil dilation.

The autonomic nervous system works with which of the following body systems to maintain homeostasis?

Endocrine Rationale: The autonomic nervous system works with the endocrine system to regulate internal functioning and maintain homeostasis.

The main nerve centers for the autonomic nervous system (ANS) are located in which of the following locations? Select all that apply.

Hypothalamus Medulla Spinal cord Rationale: The main nerve centers for the ANS are located in the hypothalamus, the medulla, and the spinal cord.

Alpha 1 receptors have which of the following actions?

Increase blood pressure Rationale: Aplpha1 receptors are found in blood vessels, in the iris, and in the urinary bladder. In blood vessels, they can cause vasoconstriction and increase peripheral resistance, thus raising blood pressure. In the urinary bladder, they cause the increased closure of the internal splinter. Beta 2 receptors are responsible for bronchial dilation, uterine smooth muscle relaxation, and increased lipolysis.

Which of the following would be assessed with parasympathetic nervous system stimulation?

Increased gastric motility Rationale: With parasympathetic nervous stimulation, gastric motility increases, secretions increase, pupils constrict, and the rectal and urinary sphincters relax to allow elimination.

Which of the following is a parasympathetic response of the lacrimal glands?

Increased secretions Rationale: A parasympathetic reaction of the lacrimal glands would be an increased amount of secretions.

After teaching a group of students about the differences between the sympathetic nervous system and the parasympathetic nervous system, the instructor determines that the students have understood the information when they state which of the following?

The sympathetic nervous system preganglionic fibers are short, while those in the parasympathetic nervous system are long. Rationale: The SNS preganglionic fibers are short; the PNS preganglionic fibers are long. The SNS ganglia are located in chains along the spinal cord; those of the PNS are located close to or within the effector tissue. The SNS is the system involved in the stress response, while the PNS is the rest and digest system. The PNS contains nicotinic and muscarinic receptors.

Sympathetic stimulation of the heart causes:

An increased rate and force of myocardial contraction. Rationale: 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 following are steps involved in norepinephrine release. Place them in the proper sequence as they would occur.

1. Action potential arrives at the axon terminal 2. Axon membrane depolarizes 3. Calcium moves into the nerve 4. Membrane contracts 5. Storage vesicles fuse with cell membrane 6. Norepinephrine travels across synapse to effector cell Rationale: When the nerve is stimulated, the action potential travels down the nerve axon and arrives at the axon terminal. The action potential then depolarizes the axon membrane. This action allows calcium into the nerve, causing the membrane to contract and the storage vesicles to fuse with the cell membrane, releasing their load of norepinephrine into the synaptic gap or cleft. The norepinephrine travels across the very short gap to very specific adrenergic receptor sites on the effector cell on the other side of the synaptic gap.

The functions of the autonomic nervous system (ANS) can be broadly described as:

Activities designed to maintain a constant internal environment, to respond to stress or emergencies, and to repair body tissues. Rationale: The functions of the ANS can be broadly described as activities designed to maintain a constant internal environment (homeostasis), to respond to stress or emergencies, and to repair body tissues.

Nerve fibers secreting norepinephrine are called:

Adrenergic fibers. Rationale: Norepinephrine is released at most postganglionic fibers of the sympathetic nervous system. Nerve fibers secreting norepinephrine are called adrenergic fibers.

Nicotinic receptors are found in which of the following areas?

Autonomic basal ganglia Rationale: Nicotinic receptors are located in the CNS, the adrenal medulla, the autonomic ganglia, and the neuromuscular junction. Muscarinic receptors are found in visceral effector organs, such as the GI tract, bladder, and heart; in sweat glands; and in some vascular smooth muscle.

Which of the following reactions results from the stimulation of nicotinicm receptors?

Muscle contraction Rationale: Nicotinicm receptors are located at neuromuscular junctions in skeletal muscle. Their activation causes muscle contraction.

Which of the following would NOT occur when nicotinic receptors are stimulated? (Mark all that apply.)

Muscle relaxation Signs and symptoms of a rest and digest reaction Rationale: 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. Options D and E are the only correct choices.

Adrenergic nerves use tyrosine from the diet to make which of the following neurotransmitters?

Norepinephrine

The body uses tyrosine in the diet to make what substance?

Norepinephrine Rationale: Norepinephrine is made by adrenergic nerves using tyrosine from the diet. Therefore Options B, C, and D are incorrect.

Which of the following would be considered functions of the autonomic nervous system? (Select all that apply).

Regulation of respiration Maintenance of water balance Control of heart rate Rationale: The ANS functions to control heart rate, water balance, and respiration. Level of consciousness, sensory perception, and muscle movement are functions of the CNS.

Most of the free norepinephrine molecules are taken up by the nerve terminal that releases them in which of the following processes?

Reuptake Rationale: Most of the free norepinephrine molecules are taken up by the nerve terminal that released them in a process called reuptake.

When describing the fight or flight response, an instructor describes various events that occur and substances that are secreted. Which substance would the instructor include as being responsible for sodium and water retention?

Aldosterone Rationale: Aldosterone causes sodium and water retention and potassium excretion. Thyroid hormone increases metabolism and efficient use of energy. The release of adrenal hormones, including cortisol, suppresses the immune and inflammatory reactions to preserve energy during the fight or flight response. Glucose is formed by glycogenolysis to increase blood glucose level and provide energy.

When describing the location of various receptors, which of the following would be located in the urinary bladder?

Alpha-1 Rationale: 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.

Which of the following is NOT a function of the body's homeostatic control systems?

Feed cells under stress Rationale: In many areas, the parasympathetic nervous system works in opposition to the SNS. This allows the autonomic system to maintain a fine control over vital functions. This is a homeostatic control system. Homeostatic control systems do not feed cells when they are under stress.

The adrenergic receptors are categorized as alpha or beta. Which of the following actions results from stimulation of alpha2 receptors?

Inhibited release of norepinephrine Rationale: Stimulation of the alpha2 receptor inhibits the release of norepinephrine.

Which of the following is a sympathetic nervous system response? Select all that apply.

Pupil dilation Increased sweating Bronchial dilation Rationale: Sympathetic nervous system responses include bronchial dilation, pupil dilation, increased sweating, piloerection, and decreased activity of the GI tract.

Students demonstrate understanding of the autonomic nervous system functions when they identify which of the following?

Regulation of respiration Rationale: The autonomic nervous system functions to regulate respirations. Sensory perception is a function of the central nervous system. Control of the level of consciousness is a function of the central nervous system. Muscle movement is a function of the central nervous system.

The nerve must contain all of the enzyme and building blocks necessary to produce which of the following to be an adrenergic nerve?

Acetylcholine Rationale: To be an adrenergic nerve, the nerve must contain all of the enzymes and building blocks necessary to produce norepinephrine.

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?

Alpha1 Rationale: B1 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.

Norepinephrine is mainly:

An excitatory neurotransmitter that stimulates the brain to generalized increased activity. Rationale: Norepinephrine functions as a circulating neurohormone, along with epinephrine. In response to adrenergic nerve stimulation, norepinephrine and epinephrine are secreted into the bloodstream by the adrenal medullae and transported to all body tissues. These catecholamines exert the same effects on target tissues as those caused by direct stimulation of the sympathetic nervous system. However, the effects last longer because the hormones are removed from the blood more slowly. Dopaminergic receptors interact with potassium and sodium ion channels.

A client is receiving a drug that helps to relax the bladder detrusor muscle. The nurse would understand that this drug is affecting which type of receptor?

Beta-2 Rationale: Relaxation of the urinary detrusor muscle occurs with stimulation of beta-2 receptors. Alpha-1 receptor stimulation would promote closure of the urinary sphincter. Alpha-2 stimulation prevents overstimulation of effector sites and moderate insulin release by the beta cells of the pancreas. Beta-1 stimulation increases myocardial activity.

The nursing instructor is explaining the role of the parasympathetic nervous system in influencing body functions. Which of the following changes in a patient's body functions would be directly related to the stimulation of the parasympathetic nervous system?

Decreased heart rate Rationale: Specific body responses to parasympathetic stimulation include decreased heart rate, increased motility of the gastrointestinal tract, and pupil constriction.

Which of the following structures is responsible for the secretion of adrenocorticotropin hormone?

Hypothalamus Rationale: The hypothalamus causes the secretion of adrenocorticotropin hormone, leading to a release of the adrenal hormones, including cortisol, which suppresses the immune and inflammatory reactions to preserve energy that otherwise might be used by these activities.

After reviewing the autonomic nervous system and cholinergic neurons, the students demonstrate a need for additional study when they identify which of the following as a location for cholinergic neurons?

Most postganglionic sympathetic nervous system nerves Rationale: Cholinergic nerves are located on all preganglionic nerves in the ANS, postganglionic nerves of the PNS and a few SNS nerves, motor nerves on skeletal muscles, and cholinergic nerves within the CNS.

Which of the following would be included when describing the parasympathetic nervous system structure and function?

Muscarinic and nicotinic receptors are found in the parasympathetic nervous system. Ganglia are located close to or within the effector tissue. Rationale: Parasympathetic ganglia are located close to or within effector tissue. The parasympathetic nervous system contains nicotinic and muscarinic receptors. The preganglionic fibers of the parasympathetic nervous system are long. The sympathetic nervous system is the stress response; the parasympathetic nervous system helps the body recuperate from the stress response. Cholinergic receptors are found in the parasympathetic nervous system.

A graduate of a nursing program is scheduled to take the NCLEX today. He wakes up and is noticing his heart is racing and his pupils are dilated. What can he attribute to this reaction?

Sympathetic nervous system Rationale: The sympathetic nervous system is stimulated by physical or emotional stress, such as strenuous exercise or work, pain hemorrhage, intense emotions, and temperature extremes. The specific body responses include increased arterial blood pressure and cardiac output and pupil dilation to aid vision. The autonomic nervous system affects the cardiovascular function to decrease heart rate responses. The patient does not suffer from a cardiac irregularity. The release of dopamine will not affect pupillary response.

Which of the following statements accurately describes the behavior of affected cells following the activation of muscarinic receptors?

The cell functions may be either excited or inhibited. Rationale: When muscarinic receptors are activated by acetylcholine, the affected cells may be excited or inhibited in their functions.

Norepinephrine is made by nerve cells using which substance?

Tyrosine Rationale: Norepinephrine is made by the nerve cells using tyrosine, which is obtained in the diet. Dihydroxyphenylalanine (dopa) is produced by a nerve, using tyrosine from the diet and other chemicals. With the help of the enzyme dopa decarboxylase, the dopa is converted to dopamine, which in turn is converted to norepinephrine in adrenergic cells.

Which of the following would be discussed when describing the parasympathetic nervous system?

Vagus nerve Rationale: The vagus nerve, originating in the cranium, is one of the most important parts of the PNS. Adrenergic receptors, norepinephrine, and MAO are aspects that would be included in the discussion of the SNS.

Which of the following would occur if a drug stimulated beta-2 receptors?

Vasodilation Rationale: Vasodilation, as well as bronchodilation and uterine relaxation, occur as a result of beta-2 stimulation. Piloerection results from stimulation of alpha-1 receptors.

Which of the following receptors is found in the beta cells of the pancreas?

Alpha-2 Rationale: Alpha-2 receptors are found in the beta cells of the pancreas. Alpha-1 receptors are found in blood vessels, the iris, and urinary bladder. Beta-1 receptors are found in cardiac tissue. Beta-2 receptors are found in the smooth muscle of the blood vessels, bronchi, periphery, and uterine muscle.

A patient is suffering from a heart rate of 42 beats per minute. Which system contributes to bradycardia?

Parasympathetic nervous system Rationale: The parasympathetic nervous system decreases heart rate. The pulmonary system will not regulate bradycardia. The autonomic nervous system increases heart rate. The peripheral vascular system regulates blood flow to the extremities.

Which of the following helps to generate heat when the core body temperature is too low?

Piloerection Rationale: The actual benefit of piloerection to humans is unknown, except that this activity helps to generate heat when the core body temperature is too low.

A nurse administers a drug that stimulates alpha-1 receptors. Which of the following would most likely occur?

Pupil dilation Rationale: Pupil dilation results from stimulation of alpha-1 receptors. Increased heart rate occurs with beta-1 stimulation. Bronchodilation results from stimulation of beta-2 receptors. Decreased GI activity results from stimulation of beta-2 receptors.

When assessing a patient who is experiencing a stress response, which of the following would the nurse expect to find? Select all that apply.

Pupil dilation Diaphoresis Tachycardia Rationale: In the stress response, tachycardia, pupil dilation, hypertension, decreased bowel sounds, and diaphoresis would be noted.

Which of the following would NOT occur in the body when muscarinic receptors are stimulated? (Mark all that apply.)

Pupil dilation Increased heart rate Rationale: Stimulation of muscarinic receptors causes pupil constriction, increased GI motility and secretions (including saliva), increased urinary bladder contraction, and a slowing of the heart rate. Thus, the only correct options are B and E.

When describing the parasympathetic nervous system, which of the following would be included?

The cells are primarily located in the sacral area of the spinal cord. Rationale: The parasympathetic nervous system has neurons in the cranium and sacral area of the spinal cord. The sympathetic nervous system is referred to as the thoracolumbar system. The sympathetic nervous system consists of short preganglionic fibers. Sympathetic nerve ganglia are located in chains running alongside the spinal cord.

The CNS structure containing groups of neurons responsible for vital cardiac, respiratory, and vasomotor functions is:

The medulla oblongata. Rationale: The medulla oblongata is the lower portion of the brainstem. It deals with autonomic functions, such as breathing and blood pressure. The cardiac center is the part of the medulla oblongata responsible for controlling the heart rate.

A famous magician is known for his outlandish feats, such as being underwater for 10 minutes while removing handcuffs. Some have postulated that he has control over his autonomic nervous system in ways that most people do not. What would be an example of an autonomic response he may have control over?

The rate of his heart beat Rationale: The autonomic nervous system controls functions essential to the life of the organism and not consciously controlled, including heart rate, blood pressure, and gastrointestinal activity. Speech, income, and oxygen diffusion within cells are not controlled by the autonomic nervous system.