CHAPTER 29 -
Most of the free norepinephrine molecules are taken up by the nerve terminal that releases them in which process?
Reuptake Most of the free norepinephrine molecules are taken up by the nerve terminal that released them in a process called reuptake.
T/F - The sympathetic and parasympathetic nervous systems work in opposition to each other, which helps regulate the body's internal systems and create a rapid response to stress situations.
True
T/F - Tyrosine obtained from the diet is used by the adrenergic nerves in the creation of norepinephrine.
True
The main nerve centers for the autonomic nervous system (ANS) are located in which locations?
Medulla Spinal cord Hypothalamus
Nicotinic receptors are found in which area?
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.
Norepinephrine is made by nerve cells using which substance?
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.
A client is experiencing major depressive disorder. Which neurotransmitter is most likely implicated?
Serotonin Serotonin abnormalities are thought to be involved in mental depression and sleep disorders.
Alpha-receptors
adrenergic receptors that are found in smooth muscles
Beta-Receptors
adrenergic receptors that are found in the heart, lungs, and vascular smooth muscle
Ganglia
groups of closely packed nerve cell bodies
Which receptor is responsible for increasing blood pressure?
Alpha 1 receptors Activation of alpha1 receptors in smooth muscle cells is thought to open ion channels, allows calcium ions to move into the cell, and produces muscle contraction, which is responsible for vasoconstriction, gastrointestinal, and bladder sphincter contraction. Alpha2 receptors are responsible for a decreased sympathetic outflow and antiadrenergic effect resulting in smooth muscle contraction. Beta1 receptors activate cardiac contraction, smooth muscle relaxation, and glycogenolysis. Beta2 receptors activate bronchodilation.
The nurse educates a client diagnosed with asthma concerning the important aspects about the prescribed selective beta2-adrenergic agonist inhaler. Which client statement indicates the need for further clarification?
"The medication will cause my heart rate to increase and will cause palpitations." The nurse needs to clarify teaching regarding that the medication is selective to beta2 receptors that affect bronchodilation. The medication does not significantly activate beta1 receptors leading to tachycardia or palpitations. The definition of agonist is that the medication will bind to the beta2receptors and activate the physiologic response, and in this case, the sympathetic nervous system.
Sympathetic Nervous System
"fight-or-flight" response mediator; composed of CNS cells from the thoracic or lumbar areas, short preganglionic axons, ganglia near the spinal cord, and long postganglionic axons that react with adrenergic receptors
Parasympathetic Nervous System
"rest-and-digest" response mediator that contains central nervous system (CNS) cells from the cranium or sacral area of the spinal cord, long preganglionic axons, ganglia near or within the effector tissue, and short postganglionic axons that react with cholinergic receptors
The nurse administers epinephrine intravenously to a client diagnosed with heart block. In what order would the nurse predict the steps of signal transduction and intracellular events that occur when the beta-adrenergic receptors are stimulated? Drag the statements into the proper order.
1) Epinephrine binds to the beta receptor and initiates intercellular activity. 2) Epinephrine-beta receptor complex activates G protein, which reacts with guanosine triphosphate. 3) Activated G protein activates the enzyme adenyl cyclase. 4) Increases in cyclic adenosine monophosphate (cAMP) occur. 5) Cyclic adenosine monophosphate (cAMP) initiates intracellular activities, including an increase in atrioventricular conduction.b
Heart rate, blood pressure, and respirations all are controlled by the __________ system.
Autonomic
A client with asthma is prescribed albuterol to dilate the bronchioles. The nurse understands that this drug is likely acting on which receptors?
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.
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?
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.
T/F - Erection of the male sex organ is an example of a sympathetic nervous system reaction.
False
T/F - The parasympathetic nervous system is responsible for the body's "fight-or-flight" response.
False
Groups of nerve bodies located outside the CNS that are packed together are called ____________.
Ganglia
A 46-year-old male client sustained a closed head injury four hours ago. He now presents to the emergency department because he is having difficulty breathing. This is a result of swelling around the:
Medulla oblongata The medulla oblongata contains groups of neurons that form the vital cardiac, respiratory, and vasomotor centers. If the respiratory center is depressed, respiratory rate and depth are decreased. The thalamus receives impulses carrying sensations such as heat, cold, pain, and muscle position sense. The hypothalamus controls pituitary hormones.
The ________ system is designed to help the body respond to both internal and external stressors.
Sympathetic
The nurse is assessing a client. What assessment finding is the clearest indicator of autonomic function?
The client's RR of 22 breaths/min The autonomic nervous system functions to regulate respirations. Voluntary motor function, hearing and sensation are not primarily within the ANS.
Autonomic Nervous System
portion of the central and peripheral nervous systems that, with the endocrine system, functions to maintain internal homeostasis
Cholinergic Receptors
receptor sites on effectors that respond to acetylcholine
Adrenergic receptors
receptor sites on effectors that respond to norepinephrine/epinephrine
Muscarinic Rreceptors
cholinergic receptors that also respond to stimulation by muscarine
Nicotinic Receptors
cholinergic receptors that also respond to stimulation by nicotine
Acetylcholinesterase
enzyme responsible for the immediate breakdown of acetylcholine when released from the nerve ending; prevents overstimulation of cholinergic receptor sites
Monoamine Oxidase
enzyme that breaks down norepinephrine, dopamine, and serotonin to make them inactive
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?
ANS 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.
A nurse is preparing to assess a patient's cerebellar function. What would the nurse expect to test?
Balance Balance and coordination are functions of the pyramidal and extrapyramidal tracts of the motor and cerebellar systems. Remote memory and mental status exam provide information about the patient's cognitive ability. Testing for sensation would address issues with specific cranial nerves or problems involving the parietal lobe.
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?
Beta 1 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.
When there is stimulation of the SNS, blood is diverted away from the GI tract. What indicates this diversion?
Decreased bowl sounds When blood is diverted away from the GI tract, bowel sounds decrease and digestion slows dramatically, sphincters are constricted, and bowel evacuation cannot occur. Increased blood glucose levels, elevated blood pressure, and decreased immune reaction are due to SNS stimulation, but are not concerned with the GI tract.
A client presented with signs and symptoms of hypothyroidism and subsequent diagnostic testing revealed low levels of thyrotropin-releasing hormone (TRH) and thyroid stimulating hormone. The care team should focus assessments and interventions on the client's:
Hypothalamus The hypothalamus coordinates and initiates many endocrine functions, including thyroid function by the release of TRH. The limbic region primarily regulates emotion and the RAS regulates sleep-wake cycles. The cranial nerves contribute to the special senses and certain motor and sensory functions in the face and neck.
