Ch 14: Structure and function of the Neurologic System

Which structure is part of the central nervous system (CNS)? A. Brain B. Somatic nervous system C. Peripheral nerve pathways D. Cranial nerves

A. Brain The brain is part of the CNS. The peripheral nervous system (PNS) consists of the cranial nerves and the spinal nerves. The PNS can be divided into the somatic nervous system and the autonomic nervous system.

Both oligodendroglia and Schwann cells share the ability to: A. Form a myelin sheath B. Remove cellular debris C. Transport nutrients D. Line the ventricles

A. Form a myelin sheath The function of oligodendroglia (oligodendrocytes) is to deposit myelin within the central nervous system (CNS). Oligodendroglia are the CNS counterpart of Schwann cells. The remaining options are not reflective of the common function of these structures.

Which cranial nerves contain parasympathetic nerves? (Select all that apply.) A. I (olfactory) B. IX (glossopharyngeal) C. III (oculomotor) D. X (vagus) E. VII (facial)

B, C, D, E All but cranial nerve I (olfactory) contain parasympathetic nerves.

The brain receives approximately what percentage of the cardiac output? A. 80% B. 40% C. 20% D. 0%

C. 20% The brain receives approximately 20% of the cardiac output, or 800 to 1000 ml of blood flow per minute.

Parkinson and Huntington diseases are associated with defects in which area of the brain? A. Thalamus B. Medulla oblongata C. Cerebellum D. Basal ganglia

D. Basal ganglia Parkinson and Huntington diseases are conditions associated with defects of the basal ganglia. No current research supports the role of any of the other options in these diseases.

Which part of the brain contains all cell bodies and dendrites of the neurons? A. Gyri B. Sulci C. White matter D. Gray matter

D. Gray matter The gray matter contains the cell bodies and dendrites of the neurons. The gyri are the convolutions of the cerebrum. The sulci are the grooves between adjacent gyri. The white matter contains myelinated nerve fibers.

Maintenance of a constant internal environment and the implementation of behavioral patterns are main functions of which area of the brain? A. Thalamus B. Epithalamus C. Subthalamus D. Hypothalamus

D. Hypothalamus Hypothalamic function falls into two major areas: (1) maintenance of a constant internal environment, and (2) implementation of behavioral patterns. The remaining options do not address these functions.

Which statement is true regarding a subdural hematoma? A. It is a collection of blood between the dura and arachnoid. B. It occurs as a result of the disruption of an artery. C. It is a collection of blood between the skull and the dura. D. It produces cerebrospinal fluid (CSF).

A. It is a collection of blood between the dura and arachnoid. A subdural hematoma is a collection of venous blood between the dura and the arachnoid. An epidural hematoma is a collection of blood between the skull and the dura that involves an arterial bleed. The pia mater closely adheres to the brain. The choroid plexuses produce CSF.

A nurse caring for an older adult patient would expect which functional changes to occur? (Select all that apply.) A. Increased risk for falls B. Loss of muscle in the arms and legs C. Decrease in the need for social interaction D. Increased agitation and frustration levels

A, B Functional changes with aging include skeletal muscle atrophy, progressive deficits in taste and smell, and a decrease in neuromuscular control with changes in gait and posture. Neither increased agitation and frustration nor a decreased need for social interaction is considered an expected change resulting from the aging process.

What evidence does the nurse expect to see when a patient experiences trauma to the hypothalamus? (Select all that apply.) A. Uneven expression of mood B. Unstable blood glucose levels C. Poor regulation of body temperature D. Visual disturbances such as blurred vision E. Nausea, vomiting, and symptoms of gastroesophageal reflux disease

A, B, C The hypothalamus forms the base of the diencephalon. Hypothalamic function controls autonomic nervous system (ANS) function, regulation of body temperature, endocrine function (e.g., unstable glucose levels), and regulation of emotional expression. Visual and gastrointestinal symptoms would not likely be related to hypothalamus function.

The aging process brings about what changes to human cells? (Select all that apply.) A. Increased neurofibrillary tangles B. Decreased myelin presence C. Imbalance of neurotransmitters D. Altered dendrite structure E. Increased neuron production

A, B, C, D Principal cellular changes associated with aging include a decrease in the number of neurons, decreased myelin, decreased number of dendritic processes and synaptic connections, intracellular neurofibrillary tangles, and an imbalance in the amount and distribution of neurotransmitters. The aging process does not bring about an increase in neuron production.

A Schwann cell: (Select all that apply) A. Can form the myelin sheath. B. Is also referred to as a neurolemmocyte. C. Affects the function of the nodes of Ranvier. D. Is located in the peripheral nervous system. E. Is responsible of decreasing conduction velocity.

A, B, C, D The Schwann cell, or neurolemmocyte, is a glial cell that wraps around and covers axons in the peripheral nervous system. Schwann cells form and maintain the myelin sheath, and the nodes of Ranvier form the spaces on either side of the Schwann cell. If the myelin layer is tightly wrapped many times around the axon, forming nodes of Ranvier, then it increases conduction velocity and the neuron is referred to as myelinated.

Which statement is true regarding the blood-brain barrier (BBB)? (Select all that apply.) A. The BBB is dependent on astrocytes. B. It uses the meningeal layers of the brain. C. It restricts the flow of large molecules, such as potassium. D. Naturally occurring inflammatory mediators affect the BBB. E. The BBB appears to play a role in slowing down the onset of degenerative brain disease.

A, C, D, E The BBB is a term used to describe cellular structures that selectively inhibit certain substances in the blood from entering the interstitial spaces of the brain or CSF. This term emphasizes the impermeability of the nervous system to large and potentially harmful molecules. Astrocytes wrap their foot processes around the epithelial cells of brain capillaries, thereby contributing to the formation of the BBB. Tight junctions between capillary endothelial cells form a barrier that regulates the passage of ions (e.g., sodium, potassium) that could interfere with nerve transmission, prevent toxins from entering the brain, and promote transport of nutrients and the removal of metabolites. Hormones, neurotransmitters, and inflammatory mediators can affect BBB permeability. Inhibiting these endogenous chemicals with drug therapy may reduce brain edema and slow the onset of degenerative brain diseases. The statement regarding the meningeal layers of the brain is incorrect.

Which pathway carries sensory information toward the central nervous system (CNS)? A. Ascending B Somatic C. Descending D. Efferent

A. Ascending Peripheral nerve pathways can be afferent (ascending) pathways that carry sensory impulses toward the CNS. The remaining options do not carry sensory information to the CNS.

Which term describes successive, rapid impulses received from a single neuron on the same synapse? A. Temporal summation B. Spatial summation C. Convergence D. Facilitation

A. Temporal summation Temporal summation refers to the effects of successive, rapid impulses received from a single neuron on the same synapse. Spatial summation refers to the combined effect of impulses from a number of neurons on a single synapse at the same time. Facilitation refers to the effects of excitatory postsynaptic potential (EPSP) on the plasma membrane potential. Convergence refers to a number of neurons firing and converging on one neuron.

The membrane that separates the brain's cerebellum from its cerebrum is the: A. Tentorium cerebelli B. Falx cerebri C. Arachnoid membrane D. Falx cerebelli

A. Tentorium cerebelli The tentorium cerebelli is a membrane that separates the cerebellum below from the cerebral structures above. The remaining options do not perform the function described in the stem.

Which is involved in pain transmission? A. Posterior horn B. Substantia gelatinosa C. Anterior horn D. Dorsal root ganglia

B. Substantia gelatinosa The substantia gelatinosa is a structure involved in pain transmission. The posterior horn (dorsal horn) is primarily composed of interneurons and axons from sensory neurons. The anterior or ventral horn contains nerve cell bodies for efferent pathways leaving the spinal cord. The dorsal root ganglion is part of the sensory ganglion.

The region responsible for the motor aspects of speech is located in the: A. Wernicke area in the temporal lobe B. Broca area in the frontal lobe C. Wronka area in the parietal lobe D. Barlow area in the occipital lobe

B. Broca area in the frontal lobe Broca speech area is the only region responsible for the motor aspects of speech.

Which area of the brain assumes the responsibility for conscious and unconscious muscle synergy and for maintaining balance and posture? A. Cerebrum B. Cerebellum C. Diencephalon D. Brainstem

B. Cerebellum The cerebellum is responsible for conscious and unconscious muscle synergy and for maintaining balance and posture. This role is not assumed by any of the remaining options.

Where is the cerebrospinal fluid produced? A. Arachnoid villi B. Choroid plexuses C. Ependymal cells D. Pia mater

B. Choroid plexuses The choroid plexuses are the structures that produce CSF; they arise from the pia mater. The remaining options do not have a role in CSF production.

Which statements are true regarding epinephrine? (Select all that apply.) A. Parasympathetic preganglionic fibers release epinephrine. B. Dopamine is the precursor of epinephrine. C. Epinephrine induces general vasodilation. D. The action of epinephrine is the same no matter which receptor it binds.

B. Dopamine is the precursor of epinephrine C. Epinephrine includes general vasodilation Dopamine is the precursor of both epinephrine and norepinephrine. Epinephrine induces general vasodilation because of the predominance of β-adrenergic receptors in the muscle vasculature. Preganglionic sympathetic fibers release epinephrine. Epinephrine varies with the type of neuroreceptor stimulated.

Which is an arterial bleed from the blood vessels that lie within the grooves of the skull? A. Subdural B. Epidural C. Subarachnoid D. Lumbar cisterna

B. Epidural An epidural hematoma develops from an arterial bleed of blood vessels that lie within the grooves in the skull. A subdural hematoma is a collection of venous blood between the dura and the arachnoid. A subarachnoid bleed occurs within the subarachnoid space, which is between the brain and tissues that cover the brain. CSF, contained within the subarachnoid space, circulates down to the large lumbar cistern, which extends from the second lumbar vertebra to the second sacral vertebra. Cisterns are expanded areas of the subarachnoid space.

What is an effect of the sympathetic nervous system? A. Stimulation of peristalsis B. Increased blood sugar levels C. Reduction in heart rate D. Pupillary constriction

B. Increased blood sugar levels In general, sympathetic stimulation promotes responses that are concerned with the protection of the individual, which include increased blood sugar levels, temperature, and blood pressure. The responses noted in the remaining options are not a result of sympathetic stimulation.

Which statement is true regarding Broca's area? A. Is responsible for receptive speech B. Is responsible for motor speech C. Results in the inability to hear D. Is located in the right cerebral hemisphere

B. Is responsible for motor speech Broca's area is found on the left and is responsible for motor speech. Deficits in this area result in the inability to form words, which is also called expressive aphasia.

Which type of axon transmits a nerve impulse at the highest rate? A. Large nonmyelinated B. Large myelinated C. Small nonmyelinated D. Small myelinated

B. Large myelinated If the myelin layer is tightly wrapped many times around the axon and is forming the nodes of Ranvier, then conduction velocity increases and the neuron is referred to as myelinated. The increased diameter of the myelinated axons allows for the transmission of impulses at a faster rate. The other options do not affect nervous impulse transmission rates.

The nurse recognizes that a patient's diagnosis of a viral infection of the brain's meningeal layer is supported by which diagnostic laboratory result? A. Chloride <110 mEq/L B. Leukocytes >10/mm3 C. Protein <10 mg/dl D. Glucose <40 mg/dl

B. Leukocytes >10/mm3 Viral infections causing meningitis will produce a white blood cell (leukocyte) count greater than 10/mm 3. The chloride level is observed in tuberculous meningitis, the protein level has little clinical significance, and the glucose level is observed in patients with acute bacterial meningitis.

Which statement is true regarding the cerebellum? A. Makes up fibers of the corticospinal tract B. Maintains balance or posture C. Controls respiration D. Is the location of cranial nerves V through VIII

B. Maintains balance or posture The cerebellum is responsible for balance and posture and is also responsible for both conscious and unconscious muscle synergy. The pons controls respirations and is the location of cranial nerves V through VIII. The fibers of the corticospinal tract are made up in the basis pedunculi.

Which is an insulating substance for the neuron? A. Schwann sheath B. Myelin C. Neurilemma D. Node of Ranvier

B. Myelin Myelin is an insulating substance. The neurilemma is the same as a Schwann sheath; it is the delicate tissue that surrounds each axon. The nodes of Ranvier are interruptions at regular intervals that occur in the myelin.

From which part of the midbrain do cranial nerves V to VIII emerge? A. Midbrain B. Pons C. Medulla oblongata D. Lateral colliculi

B. Pons The nuclei of cranial nerves V through VIII (see Table 15-6 for discussion) are located only in the pons

What name is given to a large network of neurons within the brainstem that is essential for maintaining wakefulness? A. Midbrain B. Reticular activating system C. Medulla oblongata D. Pons

B. Reticular activating system The reticular activating system is essential for maintaining wakefulness. The remaining options are not essential to this function.

The ability of the eyes to track moving objects through a visual field is primarily a function of which colliculi? A. Inferior B. Superior C. Mid D. Posterior

B. Superior The superior colliculi are involved with voluntary and involuntary visual motor movements (e.g., the ability of the eyes to track moving objects in the visual field). Tracking moving objects is not the primary function of the remaining options.

Which is a component of the midbrain? A. Cerebral hemisphere B. Tegmentum C. Cerebellum D. Medulla oblongata

B. Tegmentum The tegmentum, corpora quadrigemina, and cerebral peduncles are parts of the midbrain. The cerebral hemispheres make up the forebrain. The brainstem is composed of the midbrain, medulla oblongata, and pons.

During a synapse, what change occurs after the neurotransmitter binds to the receptor? A. The permeability of the presynaptic neuron changes; consequently, its membrane potential is changed as well. B. The permeability of the postsynaptic neuron changes; consequently, its membrane potential is changed as well. C. The postsynaptic cell prevents any change in permeability and destroys the action potential. D. The presynaptic cell synthesizes and secretes additional neurotransmitters.

B. The permeability of the postsynaptic neuron changes; consequently, its membrane potential is changed as well. The binding of the neurotransmitter at the receptor site changes the permeability of the postsynaptic neuron and, consequently, its membrane potential. The remaining options do not accurately describe the occurrence.

Which statement is true regarding upper motor neurons? A. Upper motor neurons directly influence muscles. B. They modify spinal reflex arcs. C. Upper motor neurons are located in the gray matter of the spinal cord. D. They extend their dendritic processes out of the CNS.

B. They modify spinal reflex arcs. Upper motor neurons (i.e., corticospinal tract) are the classification of motor pathways completely contained within the CNS. Their primary roles include directing, influencing, and modifying reflex arcs, lower-level control centers, and motor and some sensory neurons. The remaining options do not accurately describe the characteristic functions of upper motor neurons.

The sympathetic nervous system primarily serves to protect an individual by doing which of the following? (Select all that apply.) A. Decreasing mucous production B. Decreasing sweat excretion C. Increasing blood sugar levels D. Increasing blood pressure E. Increasing body temperature

C, D ,E In general, sympathetic stimulation promotes responses that are concerned with the protection of the individual, which include increasing blood sugar levels, temperature, and blood pressure. The remaining options are not protective measures resulting from initiatives made by the sympathetic nervous system.

The collateral blood flow to the brain is provided by the: A. Carotid arteries B. Basal artery C. Circle of Willis D. Vertebral arteries

C. Circle of Willis The arterial circle (circle of Willis) (see Figure 15-20) is a structure credited with the ability to compensate for reduced blood flow from any one of the major contributors (collateral blood flow). The remaining options are not considered sources of collateral blood flow.

What parts of the brain mediate the expression of affect, both emotional and behavioral states? A. Hypothalamus and subthalamus B. Parietal and frontal lobes C. Limbic system and prefrontal cortex D. Basal ganglia and medulla oblongata

C. Limbic system and prefrontal cortex Extensive connections with the limbic system and prefrontal cortex mediate the expression of affect, both emotional and behavioral states. The remaining options are not involved in these expressions.

From which part of the midbrain do cranial nerves IX to XII emerge? A. Midbrain B. Pons C. Medulla oblongata D. Lateral colliculi

C. Medulla oblongata The nuclei of cranial nerves IX through XII (see Table 15-6 for discussion) are located only in the medulla oblongata.

Which nerves are capable of regeneration? A. Nerves within the brain and spinal cord B. Peripheral nerves that are cut or severed C. Myelinated nerves in the peripheral nervous system D. Unmyelinated nerves of the peripheral nervous system

C. Myelinated nerves in the peripheral nervous system Nerve regeneration is limited to only myelinated fibers and generally occurs only in the peripheral nervous system.

Which of the meninges closely adheres to the surface of the brain and spinal cord and follows the sulci and fissures? A. Dura mater B. Arachnoid C. Pia mater D. Inner dura

C. Pia mater The delicate pia mater closely adheres to the surface of the brain and spinal cord and even follows the sulci and fissures. The remaining options are not represented in the description provided in the stem.

Thought and goal-oriented behaviors are functions of which area of the brain? A. Cerebellum B. Limbic system C. Prefrontal lobe D. Occipital lobe

C. Prefrontal lobe The prefrontal area is responsible for goal-oriented behavior (i.e., ability to concentrate), short-term or recall memory, and the elaboration of thought and inhibition on the limbic (emotional) areas of the CNS. The remaining options are not involved in these functions.

The neurotransmitter, norepinephrine, is secreted in the: A. Somatic nervous system B. Parasympathetic preganglion C. Sympathetic postganglion D. Parasympathetic postganglion

C. Sympathetic postganglion Most postganglionic sympathetic fibers release norepinephrine (adrenaline). The remaining options do not reflect the correct site of norepinephrine secretion.

Norepinephrine produces what primary response? A. Increased contractility of the heart B. Release of renin from the kidney C. Vasoconstriction D. Pupillary dilation

C. Vasoconstriction The primary response from norepinephrine is the stimulation of the α1-adrenergic receptors that cause vasoconstriction. The remaining options do not accurately reflect the primary response of norepinephrine.

The function of arachnoid villi is to: A. Produce cerebrospinal fluid B. Provide nutrients to the choroid plexuses C. Transmit impulses within the meninges D. Absorb cerebrospinal fluid

D. Absorb cerebrospinal fluid CSF is reabsorbed by means of a pressure gradient between the arachnoid villi and the cerebral venous sinuses. The remaining options do not accurately describe the function of arachnoid villi.

Which neurons transmit impulses from neuron to neuron? A. Unipolar neurons B. Sensory neurons C. Motor neurons D. Interneurons

D. Interneurons Interneurons, or associational neurons, transmit impulses from neuron to neuron. Motor neurons transmit impulses away from the CNS. Sensory neurons carry impulses from the peripheral sensory receptors to the CNS. Unipolar neurons have one process that branches shortly after leaving the cell body.

Reflex activities concerned with heart rate, blood pressure, respirations, sneezing, swallowing, and coughing are controlled by which area of the brain? A. Pons B. Midbrain C. Cerebellum D. Medulla oblongata

D. Medulla oblongata The medulla oblongata makes up the myelencephalon and is the lowest portion of the brainstem. Reflex activities, such as heart rate, respiration, blood pressure, coughing, sneezing, swallowing, and vomiting, are controlled only in this area.