Chapter 19: Introduction to Nerves and the Nervous System
The patient is diagnosed with myasthenia gravis, a condition in which antibodies block, alter, or destroy the receptors for acetylcholine. What symptom would the nurse expect this patient to display? A) Muscle dysfunction B) Seizures C) Uncoordinated movements D) Sleep all the time
Ans: A Feedback: Acetylcholine communicates between nerves and muscles so inability of this neurotransmitter to function properly, whether blocking, altering, or destroying the receptors, would result in muscle dysfunction. Inadequate gamma-aminobutyric acid would result in seizures. Inadequate dopamine would result tin uncoordinated movements. Serotonin is important in arousal and sleep.
Which neurotransmitter communicates between nerves and muscles? A) Acetylcholine B) Dopamine C) Gamma-aminobutyric acid (GABA) D) Serotonin
Ans: A Feedback: Acetylcholine, which communicates between nerves and muscles, is also important as the preganglionic neurotransmitter throughout the autonomic nervous system and as the postganglionic neurotransmitter in the parasympathetic nervous system and in several pathways in the brain. Dopamine is involved in the coordination of impulses and responses, both motor and intellectual. GABA inhibits nerve activity. Serotonin is important in arousal and sleep.
The nurse is caring for a patient whose recent ultrasound of the carotids diagnosed a 90% occlusion of the right carotid artery and a 92% occlusion of the left carotid artery. The patient asks the nurse, If one of these arteries becomes completely occluded will I have a stroke? What is the nurses best response? A) A common vessel receiving all blood to the head called the circle of Willis will distribute blood from other arteries to the brain as needed. B) A stroke is caused by lack of blood supply to a part of the brain so if your right carotid artery becomes blocked youll have a stroke on the right side of your brain. C) It is hard to predict exactly what will happen so youll have to wait until your provider sees you because only the provider can answer that question. D) With only 10% of the blood needed getting through your right artery and 8% through your left artery, you could have a stroke now.
Ans: A Feedback: All the arteries that supply blood to the head deliver blood to a common vessel at the bottom of the brain called the circle of Willis, which distributes the blood to the brain when it is needed. The role of the circle of Willis becomes apparent when someone has an occluded carotid artery. Although the passage of blood through one of the carotid arteries may be negligible, the areas of the brain on that side will still have a full blood supply because of the blood sent to those areas through the circle of Willis. All other options are incorrect.
The student nurses are learning about the nervous system. What would the students learn are capable of conducting along the entire membrane of the nerve? A) Action potentials B) Engrams C) Chemical synapses D) Sodiumpotassium channels
Ans: A Feedback: Nerve membranes, which are capable of conducting action potentials along the entire membrane, send messages to nearby neurons or to effector cells that may be located inches to feet away via this electrical communication system. Other options are incorrect.
The physiology instructor explains to the students that some substances increase actual learning. What is one of these substances? A) Oxytocin B) Acetylcholine C) Serotonin D) Dopamine
Ans: A Feedback: Oxytocin and mild stress act to increase actual learning. Childbirth is the only time that oxytocin levels increase and this phenomenon is not clearly understood. Acetylcholine, serotonin, and dopamine do not increase actual learning; they function as neurotransmitters.
The nurse is caring for a patient whose emotions often swing from one extreme to the other. The patients spouse tells the nurse these mood swings started when the patient awoke from a coma following a serious head trauma. What area of the brain does the nurse suspect was damaged? A) The limbic system B) The forebrain C) The hindbrain D) The cerebellum
Ans: A Feedback: Stimulation of the limbic system, which appears to be responsible for the expression of emotions, may lead to anger, pleasure, motivation, and stress. The forebrain is where thinking and coordination of sensory and motor activity occur. The hindbrain controls vital functions and arousal. The cerebellum controls motor functions that regulate balance.
The nurse is caring for a patient with a malignant brain tumor. The patient asks the nurse why the tumor is being treated with radiation instead of chemotherapy. The nurses explanation involves what important information? A) Medications have difficulty crossing the bloodbrain barrier. B) Neurons in the brain are easily damaged by chemotherapy. C) Tumors arising from nervous tissue are not impacted by chemotherapy. D) Chemotherapy reduces nerve transmission and cannot be used.
Ans: A Feedback: The bloodbrain barrier is a functioning boundary that plays a defensive role by keeping toxins, proteins, and other large structures out of the brain and preventing their contact with the sensitive and fragile neurons. As a result, medications like chemotherapy can have difficulty crossing this barrier to reach the tumor. The other answers are neither true nor the correct option.
A nurse is caring for a patient who is having an adverse drug reaction. The patient is experiencing tremors, is unable to hold his or her head up, and is having difficulty sitting up in bed. The nurse suspects that this is due to what? A) An interference with the extrapyramidal system B) A faulty engram C) An alteration in the reticular activating system D) An interference with a neurotransmitter
Ans: A Feedback: The extrapyramidal system coordinates unconscious motor activity that regulates control of position and posture. An engram is a reverberating circuit of action potentials that becomes a long-term, permanent memory in the presence of the proper neurotransmitters and hormones. The reticular activating system, which is located in the hindbrain, controls arousal and awareness of stimuli and contains the sleep center. A neurotransmitter is a chemical that stimulates postsynaptic cells either by exciting or by inhibiting them.
While diagramming the brain for their anatomy and physiology class, the nursing students would place the swallowing center where? A) Hindbrain B) Right hemisphere C) Forebrain D) Left hemisphere
Ans: A Feedback: The pons and medulla oblongata are in the hindbrain and control basic, vital functions, such as the respiratory centers, which control breathing; the cardiovascular centers, which regulate blood pressure; the chemoreceptor trigger zone and emetic zone, which control vomiting; and the swallowing center, which coordinates the complex swallowing reflex. Therefore, options B, C, and D are incorrect.
The sensory nerves enter the brain and react with related nerves to cause a reaction. What mediates this reaction? A) Muscles or glands B) The limbic system C) The cerebral cortex D) Neurotransmitters
Ans: A Feedback: 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.
Two nursing students are giving an oral presentation on the forebrain. What information will they include about this area? (Select all that apply.) A) Coordinates speech and communication B) Area where learning takes place C) Houses the extrapyramidal motor system D) Cranial nerves emerge from here. E) The swallowing center is here.
Ans: A, B, C Feedback: The forebrain is made up of two cerebral hemispheres joined together by the corpus callosum. The two hemispheres contain the sensory and motor neurons. It also contains areas that coordinate speech and communication and is thought to be where learning takes place. Cranial nerves emerge from the hindbrain, which is where the swallowing center is located as well.
What part of the neuron carries information into the neuron from other neurons? A) Axon B) Dendrite C) Nucleus D) Soma
Ans: B Feedback: Dendrites carry information to the nerve and axons; they also carry information from a nerve to be transmitted to effector cells, which are found in muscles, glands, or another nerve. Soma refers to the cell body. The nucleus is the central part of a cell, which is responsible for the cells growth, reproduction, and metabolism.
What is the purpose of the myelin sheath? A) Protects the nerve from damage B) Speeds electrical conduction C) Produces Schwann cells D) Secretes neurotransmitters
Ans: B Feedback: Long nerves are myelinated: They have a myelin sheath that speeds electrical conduction and protects the nerves from the fatigue that results from frequent formation of action potentials, not from damage. Although myelin sheaths have Schwann cells, they do not produce these cells and the myelin sheath does not secrete neurotransmitters.
As the nursing students learn about the functioning of the nervous system, they learn that the energy required by the nerves is provided by what? A) Dopamine and electricity B) Oxygen and glucose C) Sodium and potassium D) Acetylcholine and serotonin
Ans: B Feedback: Nerves require energy (i.e., oxygen and glucose) and the correct balance of the electrolytes sodium and potassium to maintain normal action potentials and transmit information into and out of the nervous system. Energy required by the nerves is not provided by dopamine, electricity, acetylcholine, or serotonin.
The anatomy and physiology instructor is discussing neurotransmitters with the prenursing anatomy and physiology class. What neurotransmitter would the instructor tell the students is a catecholamine classified as a hormone when it is released from the adrenal medulla? A) Ephedrine B) Norepinephrine C) Dopamine D) Acetylcholine
Ans: B Feedback: 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. Therefore, options A, C, and D are incorrect.
The nurse is caring for a patient with meningitis who is not responding to the prescribed antibiotic and whose condition continues to deteriorate. What rationale will the nurse give the family to explain why the antibiotic is not as effective as it was hoped? A) The meninges do not have a blood supply. B) The bloodbrain barrier prevents the antibiotics from crossing into the brain. C) The circle of Willis redirects the antibiotic elsewhere. D) The pressure in the hindbrain prevents entry into the skull.
Ans: B Feedback: The bloodbrain barrier works to keep large molecules out of the brain and away from the nerves. Most antibiotics are protein bound and cannot pass through the bloodbrain barrier. When the infection becomes severe, the bloodbrain barrier will stop being effective and the antibiotics can pass into the brain. The brain has a unique blood supply to protect the neurons from lack of oxygen and glucose. After the bloodbrain barrier allows the antibiotic to pass through, the circle of Willis distributes the blood to the areas of need. If someone has an occluded carotid artery, which could build pressure up in the area, the circle of Willis can redirect the blood supply and provide a full blood supply to the affected areas.
The nurse is caring for a patient who has an injured hindbrain. What would the nurse expect to find altered when assessing the patient? A) Arousal and awareness B) Basic vital functions C) Coordination and motor activity D) Learning and motivation
Ans: B Feedback: The hindbrain contains centers that control basic vital functions (e.g., blood pressure, respirations, vomiting). The reticular activating system in the medulla controls arousal and awareness. Learning and motivation occur in the cerebral cortex. Coordination and motor activity are controlled through the cerebellum and basal ganglia.
Neurotransmission is important in the function of the central nervous system (CNS). For neurotransmission to occur, how do neurons communicate with other cells? A) Selectively B) Chemically C) Excitably D) Accessibly
Ans: B Feedback: The transmission of information between two nerves or between a nerve and a gland or muscle is chemical. Options A, C, and D are incorrect.
When a neuron is stimulated and causes depolarization of the nerve, what occurs? A) Calcium rushes into the cell. B) Sodium rushes into the cell. C) Potassium rushes into the cell. D) Sodium and potassium are actively pumped out to the cell.
Ans: B Feedback: When depolarization occurs, sodium rushes into the cell. During repolarization, potassium is pumped out of the cell and the resting membrane potential is reestablished. Calcium ions decrease the cell membranes permeability to sodium and increase the threshold needed to depolarize the cell.
What neurotransmitter inhibits overexcitability and is important in preventing seizure activity in a patient? A) Acetylcholine B) Dopamine C) Gamma-aminobutyric acid (GABA) D) Serotonin
Ans: C Feedback: GABA is found in the brain and inhibits nerve activity. It is important in preventing overexcitability or stimulation such as seizure activity. Acetylcholine communicates between nerves and muscles. Dopamine is involved in the coordination of impulses and responses, both motor and intellectual. Serotonin is found in the limbic system and is important in arousal and sleep as well as in preventing depression and promoting motivation.
While discussing the central nervous system (CNS), the nursing instructor tells the students that the major inhibitory neurotransmitter in the CNS is what? A) Acetylcholine B) Dopamine C) Gamma-aminobutyric acid (GABA) D) Serotonin
Ans: C Feedback: GABA, which is found in the brain, inhibits nerve activity and is important in preventing overexcitability or stimulation such as seizure activity. Acetylcholine, which communicates between nerves and muscles, is also important as the preganglionic neurotransmitter throughout the autonomic nervous system and as the postganglionic neurotransmitter in the parasympathetic nervous system and in several pathways in the brain. Dopamine is involved in the coordination of impulses and responses, both motor and intellectual. Acetylcholine, dopamine, and serotonin are not the major inhibitory neurotransmitter in the CNS. Serotonin is important in arousal and sleep.
A patient who nearly drowned is brought to the emergency department. The paramedics tell the nurse the patient was anoxic for approximately 5 minutes. Because of this anoxia, what might happen to the nerve cells? A) The nerves might not be able to repolarize. B) The nerves might not be able to depolarize. C) The nerves might not be able to maintain the sodiumpotassium pump. D) The nerves might not be able to maintain their action potential.
Ans: C Feedback: If a person has anoxia or hypoglycemia, the nerves might not be able to maintain the sodiumpotassium pump, and with continued lack of oxygen and/or glucose, the nerve cell will die. Other options are incorrect.
A nurse is working on a surgical unit and has several patients who require preoperative teaching. Which patient demonstrates behavior indicating this is an appropriate time to begin teaching? A) A patient who is wide eyed and extremely frightened about being put to sleep B) A patient who appears to be unconcerned about what is happening and wants to watch his favorite TV show C) A patient who is clearing her throat several times while asking the nurse questions during their conversation and who appears to be slightly stressed D) A patient who is getting up and down from the bed, talking very fast, and appears to be extremely anxious
Ans: C Feedback: Several substances appear to affect learning. Antidiuretic hormone (ADH), which is released during reactions to stress, is one such substance. Although too much stress prevents learning, feeling slightly stressed may increase a persons ability to learn. A patient who is a little nervous about upcoming surgery, for example, seems to display a better mastery of facts about the surgery and postoperative procedures than a patient who is very stressed and scared or one who appears to show no interest or concern.
The nursing instructor is talking about neurotransmitters, including which of these chemicals? A) Calcium ion B) Acetylcholinesterase C) Acetylcholine D) Monoamine oxidase
Ans: C Feedback: The cholinergic system uses acetylcholine as its neurotransmitter. A calcium ion is an electrolyte circulating in the serum. Acetylcholinesterase is an enzyme that breaks down acetylcholine. Monoamine oxidase is an enzyme that breaks down the neurotransmitter norepinephrine.
The nursing instructor is teaching the new nursing students about patient teaching. Where in the brain would the instructor tell the student nurses is the area where learning takes place? A) The area that coordinates sensation B) The area that coordinates movement C) The areas that coordinate speech and communication D) The areas that communicate between motor and sensory neurons
Ans: C Feedback: The forebrain is made up of two cerebral hemispheres that contain areas that coordinate speech and communication and are thought to be the area where learning takes place.
The physiology instructor is discussing the limbic system. What would the instructor say occurs with stimulation of this area? A) Intelligence B) Heart rate C) Mood D) Reflexes
Ans: C Feedback: The limbic system is an area of the brain that contains high levels of three neurotransmitters: epinephrine, norepinephrine, and serotonin. Stimulation of this area appears to be responsible for the expression of emotions (e.g., anger, pleasure, motivation, stress).
A female patient has experienced a stroke affecting the right side of her brain. What will the nurse expect to assess in this patient? A) Inability to recall the name of her best friend B) Inability to state her telephone number C) Inability to distinguish a spoon from a fork D) Inability to recall how to apply her makeup
Ans: C Feedback: The right side of the brain is the artistic side and is concerned with forms and shapes. This patient could have difficulty distinguishing the roundness of the spoon with the straight line of the top of the fork. The left side of the brain is more analytical and is concerned with names, numbers, and process.
The anatomy and physiology instructor discusses the thalamus with the nursing class. The instructor tells the students that the thalamus does what? A) Relays motor impulses from the cortex to the spinal cord B) Is responsible for voluntary movement C) Sends information into the cerebrum to transfer sensations D) Helps maintain red blood cell (RBC) production
Ans: C Feedback: The thalamus sends direct information into the cerebrum to transfer sensations, such as cold, heat, pain, touch, and muscle sense. Motor fibers from the cortex cross to the other side of the spinal cord before emerging to interact with peripheral effectors. In this way, motor stimuli coming from the right side of the brain affect motor activity on the left side of the body. The limbic system is not responsible for voluntary movement or RBC production.
An 87-year-old woman undergoes extensive surgery for an acoustic neuroma (a benign tumor of the inner ear), and 6 hours after surgery, she hemorrhages and goes into a coma. After awaking and 2 months of therapy, she is transferred to a long-term care facility. Due to damage in the midbrain, the nurse caring for the patient will expect the patient to exhibit what? A) Difficulty in sleeping B) Difficulty in hearing C) Difficulty in distinguishing hot and cold D)Difficulty in speaking
Ans: C Feedback: The thalamus, located in the midbrain, is responsible for temperature control. The patient will have difficulty distinguishing hot and cold. Centers of control for sleep and hearing are found in the hindbrain and areas that control speech and communication are found in the forebrain.
When a person learns, this action begins as an electrical circuit called what? A) Impulse B) Synapse C) Memory D) Engram
Ans: D Feedback: Learning begins as an electrical circuit called an engram, a reverberating circuit of action potentials that eventually becomes a long-term, permanent memory in the presence of the proper neurotransmitters and hormones.
What brings information from the central nervous system (CNS) to the peripheral nervous system (PNS)? A) Motor nerves B) Synapses C) Afferent neurons D) Sensory nerves
Ans: D Feedback: The PNS is composed of sensory receptors that bring information into the CNS and motor nerves that carry information away from the CNS to facilitate response to stimuli. Synapses are the gaps between neurons. Afferent fibers are nerve axons that run from the peripheral receptors into the CNS.
A student asks the anatomy and physiology instructor to explain the two hemispheres of the brain and what they regulate. What statement, if made by the instructor, is accurate? A) The hemispheres regulate the electrical conduction system of the brain. B) The hemispheres regulate the afferent conduction system. C) The hemispheres regulate the efferent conduction system. D) The hemispheres regulate communication between sensory and motor neurons.
Ans: D Feedback: The cerebral cortex consists of two hemispheres, which regulate the communication between sensory and motor neurons and are the sites of thinking and learning. Options A, B, and C are incorrect.
A 46-year-old male patient sustained a closed-head injury 4 hours ago. He presents to the emergency department with difficulty breathing. What area of the brain does the nurse suspect is injured based on the patients symptoms? A) Thalamus B) Cerebrum C) Pituitary D) Medulla oblongata
Ans: D Feedback: The hindbrain, which runs from the top of the spinal cord into the midbrain, is the most primitive area of the brain and contains the brainstem, where the pons and medulla oblongata are located. This area of the brain controls basic vital functions such as the respiratory centers, which control breathing; the cardiovascular centers, which regulate blood pressure; the chemoreceptor trigger zone and emetic zone, which control vomiting; the swallowing center, which coordinates the complex swallowing reflex; and the reticular activating system (RAS), which controls arousal and awareness of stimuli and contains the sleep center. The midbrain contains the thalamus and hypothalamus and the limbic system that transfer sensations into the cerebrum and control temperature. The pituitary gland is known as the master gland, controlling other glands with hormones secreted here.
The nursing instructor explains the limbic system contains what neurotransmitters? A) Acetylcholine, epinephrine, and serotonin B) Gamma-aminobutyric acid, dopamine, and serotonin C) Epinephrine, dopamine, and gamma-aminobutyric acid D) Epinephrine, norepinephrine, and serotonin
Ans: D Feedback: The limbic system contains high levels of epinephrine, norepinephrine, and serotonin. Dopamine, acetylcholine, and gamma-aminobutyric acid are found in the brain but not primarily in the limbic system. Options A, B, and C are incorrect.
What would a nurse describe to a peer as a factor in increasing synaptic transmission? A) Enzymes B) Electrical impulse C) Calcium reaction D) Neurotransmitter
Ans: D Feedback: The nerve axon, called the presynaptic nerve, releases a chemical called a neurotransmitter into the synaptic cleft; the neurotransmitter reacts with a very specific receptor site on the postsynaptic cell to cause a reaction that increases synaptic transmission. Enzymes break down the neurotransmitter. The synaptic transmission is an electrical impulse. Calcium is an electrolyte but does not increase synaptic transmission.
