Chapter 56: Nervous System

Question 1

Brain, spinal cord, cranial nerves I and II

Answer 1

Central nervous system.

Question 2

Cranial nerves III to XII, spinal nerves, autonomic nervous system

Answer 2

Peripheral nervous system

Question 3

Primary functional unit of the NS. Characterized by: excitability (ability to generate a nerve impulse), conductivity (ability to transmit an impulse), and influence (ability to influence other neurons, muscle cells, or glandular cells by transmitting nerve impulses to them).
Consist of: cell body, dendrites, and an axon

Answer 3

Neurons

Question 4

Provide support, nourishment and protection to neurons; more numerous than neurons. Divided into two types.

Answer 4

Glial cells

Question 5

Specialized macrophages capable of phagocytosis. Protect the neuron. Mobile within the brain and multiply when the brain is damaged

Answer 5

Macroglia

Question 6

Most abundant type of microglial cell. Found primarily in the gray matter and provide structural support to neurons. Delicate processes form the blood-brain barrier with the endothelium of the blood vessels. When the brain is injured, they act as phagocytes for neuronal debris.

Answer 6

Astrocytes

Question 7

Specialized cells that produce the myelin sheath of the nerve fibers in the CNS and are primarily found in the white matter of the CNS (Schwann cell myelinated the nerve fibers in the periphery). Type of microglial cell.

Answer 7

Oligodendrocytes

Question 8

Line the brain ventricles and aid in the secretion of cerebrospinal fluid. Type of microglial cell

Answer 8

Ependymal cells

Question 9

Nerve regeneration

Answer 9

If the axon of the nerve cell is damaged, the cell attempts to repair itself. Damaged nerve cells attempt to grow back to their original destinations by sprouting many branches from the damaged ends of their axons. Axons in the CNS are generally less successful than peripheral axons in their regeneration. Injured nerve fibers in the PNS can regenerate by growing within the protective myelin sheath of the supporting Schwann cells if the cell body is still intact.

Question 10

Chemicals that affect the transmission of impulses across the synaptic cleft

Answer 10

Neurotransmitters

Question 11

A decrease in the neurons that secrete this neurotransmitter is seen in Alzheimer’s disease. Myasthenia gravis results from a reduction in the receptors for the NT. Activates muscles.

Answer 11

Acetylcholine

Question 12

Produced in several areas of the brain. Involved in emotions and moods and regulating motor control. Parkinson’s disease results from destruction of the neurons that secrete this NT.

Answer 12

Dopamine

Question 13

Composed of right and left hemispheres and is divided into four lobes: frontal, temporal, occipital, parietal, and occipital. Functions are multiple and complex.

Answer 13

Cerebrum

Question 14

A group of structures located centrally in the cerebrum and midbrain. Initiation, execution, and completion of voluntary movements, learning, emotional response, and automatic movements associated with skeletal muscle activity (e.g. swinging the arms while walking, swallowing saliva, and blinking)

Answer 14

Basal ganglia

Question 15

Lies directly above the brainstem and is the major relay center for afferent inputs to the cerebral cortex

Answer 15

Thalamus

Question 16

Located just inferior to the thalamus and slightly in front of the midbrain. It regulates the ANS and the endocrine system.

Answer 16

Hypothalamus

Question 17

Located near the inner surfaces of the cerebral hemispheres and is concerned with emotion,a aggression, feeding behavior, and sexual response.

Answer 17

Limbic system

Question 18

Includes the midbrain, pons, and medulla.

Answer 18

Brainstem

Question 19

Coordinates voluntary movement and maintains trunk stability and equilibrium

Answer 19

Cerebellum

Question 20

The area of skin innervated by the sensory fibers of a single dorsal root of a spinal nerve. Give a general picture of somatic sensory innervation by spinal segments. A muscle group innervated by the primary motor neurons of a single ventral root.

Answer 20

Dermatomes/myotomes.

Question 21

12 pained nerves composed of cell bodies with fibers that it from the cranial cavity. Some are only sensory, some only motor, and some both.

Answer 21

Cranial nerves. Olfactory (I; sensory; smell); optic (II; sensory; vision); Oculomotor (III; motor; eye movement); Trochlear (IV; motor; eye movement); Trigeminal (V; sensory); Abducens (VI; motor; eye movement); Facial (VII; motor- facial muscles and cheek muscles; sensory- taste anterior 2/3 of tongue); Vestibulocochlear (VIII; sensory; equilibrium and auditory); glossopharyngeal (IX; sensory- taste; motor- pharyngeal muscles); Vagus (X; sensory- viscera of thorax and abdomen; motor- larynx and pharyngeal; parasympathetic- heart, lungs, most of digestive system); accessory (XI; motor; sternocleidomastoid and trapezius); Hypoglossal (XII; motor; tongue)

Question 22

Divided into the parasympathetic and sympathetic systems. Governs involuntary functions of cardiac muscle, smooth muscle, and glands through both efferent and afferent pathways).

Answer 22

Autonomic nervous system

Question 23

Major NT released by the postganglionic fibers is norepinephrine, and the NT released by the preganglionic fibers is acetylcholine. Activates the mechanisms required for the “fight-or-flight” response that occurs throughout the body. Increases the rate and force of heart contraction.

Answer 23

Sympathetic NS.

Question 24

Acetylcholine is the NT released by both preganglionic and postganglionic nerve endings. Geared to act in localized and discrete regions. Serves to conserve and restore the body’s energy stores. Decreases heart rate and force

Answer 24

Parasympathetic NS

Question 25

A physiologic barrier between blood capillaries and brain tissue. Protects the brain from harmful agents, while allowing nutrients and gases to enter. Lipid-soluble compounds enter the brain easily, whereas water-soluble and ionized drugs enter the brain and the spinal cord slowly. Affects the penetration of drugs. Only certain drugs can enter the CNS from the blood stream.

Answer 25

Blood-brain barrier

Question 26

Protects the brain from external trauma. Composed of 8 cranial bones and 14 facial bones.

Answer 26

Skull

Question 27

Gerontologic considerations

Answer 27

CNS: gradual loss of neurons in certain areas of the brainstem, cerebellum, and cerebral cortex. With loss of neurons, the ventricles wider or enlarge, brain weight decreases, cerebral blood flow decreases, and CSF production declines. PNS: degenerative changes in myelin cause a decrease in nerve conduction. Coordinated neuromuscular activity, such as the maintenance of blood pressure in response to changing positions, is altered (more likely to experience orthostatic hypotension). Decreases in memory, vision, hearing, taste, smell, vibration and position sense, muscle strength, and reaction time. Decreases in taste and smell perception. Reduced hearing and vision. Problems with balance and coordination- at risk for falls and fractures.

Question 28

Tests for cerebral function (mental status)

Answer 28

General appearance/behavior. Cognition. Mood/affect.

Question 29

Tests for the motor system

Answer 29

Weakness (pronator drift). Muscle tone. Balance/coordination (cerebellar function).

Question 30

Sensory system tests

Answer 30

Touch, pain, temp, vibration. Position (Romberg test).

Question 31

Neuro dx tests

Answer 31

CT. MRI and MRA (MRI with angiography). PET and SPECT. Ultrasound. Cerebral angiography (risk for a stroke). Lumbar puncture. Pyelogram. EEG. EMG

Question 32

Most common method of sampling CSF. Contraindicated in the presence of increased intracranial pressure or infection at the site of puncture. Before the procedure, have the pt void. Most commonly, pt is side-lying. Don't sedate. Monitor for headache intensity, meningeal irritation (nuchal rigidity), or s/s of local trauma (e.g. hematoma, pain).

Answer 32

Lumbar puncture

Question 33

Xray of spinal cord and vertebral column after injection of contrast medium into subarachnoid space. Used to detect spinal lesions (e.g. herniated or ruptured disc, spinal tumor). Inform pt that test is performed with pt on tilting table that is moved during test. Pts should lie flat for a few hours post-procedure. Monitor neurologic signs and VS. Headache, nausea, and vomiting may occur after procedure

Answer 33

Myelogram

Question 34

Serial x-ray visualization of intracranial and extra cranial blood vessels is performed to detect vascular lesions and tumors of brain. Assess pt for stroke risk before procedure, since thrombi may be dislodged during procedure. Withhold proceeding meal. Explain that the pt will have hot flush of head and neck when contrast medium is injected. Administer premedication. Explain pt may need to be absolutely still during procedure. Post- monitor neuro signs and VS every 15-30 min for first 2 hr, then every 2 hr for 24 hrs. Maintain bed rest until pt is alert and VS are stable. Report any neuro status changes.

Answer 34

Cerebral angiography

Question 35

Electrical activity of brain is recorded by scalp electrodes to evaluate seizure disorders, cerebral diseases, CNS effects of systemic diseases, brain death. Inform pt that procedure is noninvasive and without danger of electrical shock. Determine if any meds (e.g. tranquilizers, anti seizure drugs) should be withheld.

Answer 35

Electroencephalography (EEG)

Question 36

Electrical activity associated with nerve and skeletal muscle is recorded by insertion of needle electrodes to detect muscle and peripheral nerve disease. Inform pt that pain and discomfort are associated with insertion of needles.

Answer 36

Electromyography (EMG) and nerve conduction studies

Question 37

Electrical activity associated with nerve conduction along sensory pathways is recorded by electrodes placed on skin and scalp. Stimulus generates the impulse. Procedure is used to dx disease (e.g. multiple sclerosis), locate nerve damage, and monitor function intraoperatively.

Answer 37

Evoked potentials

Question 38

How should the nurse assess cranial nerves III, IV, and VI? a) check the pt's gag reflex b) test the pt's eye movements c) ask the pt to smile and frown d) Have the pt stick out his tongue

Answer 38

b) test the pt's eye movements

Question 39

In a pt with a disease that affects the myelin sheath of nerves, such as MS, the glial cells affected are the a) microglia b) astrocytes c) ependymal cells d) oligodendrocytes

Answer 39

d) oligodendrocytes

Question 40

Drugs or disease that impair the function of the extrapyramidal system may cause loss of a) sensations of pain and temperature b) regulation of the ANS c) integration of somatic and special sensory inputs d) autonomic movements associated with skeletal muscle activity

Answer 40

d) autonomic movements associated with skeletal muscle movements

Question 41

An obstruction of the anterior cerebral arteries will affect functions of a) visual imaging b) balance and coordination c) judgement, insight, and reasoning d) visual and auditory integration for language comprehension

Answer 41

c) judgement, insight, and reasoning

Question 42

Paralysis of lateral gaze indicates a lesion of cranial nerve a) II b) III c) IV d) VI

Answer 42

d) VI

Question 43

A result of stimulation of the PSNS is (SATA) a) constriction of the bronchi b) dilation of skin blood vessels c) increased secretion of insulin d) increased blood glucose levels e) relaxation of the urinary sphincters

Answer 43

a) constriction of the bronchi b) dilation of skin blood vessels c) increased secretion of insulin e) relaxation of the urinary sphincters

Question 44

Assessment of muscle strength of older adults cannot be compared with that of younger adults because a) stroke is more common in older adults b) nutritional status is better in young adults c) most young people exercise more than older people d) aging leads to a decrease in muscle bulk and strength

Answer 44

d) aging leads to a decrease in muscle bulk and strength

Question 45

Data regarding mobility, strength, coordination, and activity tolerance are important for the nurse to obtain because a) many neurologic diseases affect one or more of these areas b) pts are less able to identify other neurologic impairments c) these are the first functions to be affected by neurologic diseases d) aspects of movement are the most important function of the nervous system

Answer 45

a) many neurologic diseases affect one or more of these areas

Question 46

During neurologic testing, the pt is able to perceive pain elicited by pinprick. Based on this finding, the nurse may omit testing for a) position sense b) patellar reflexes c) temperature perception d) heel-to-shin testing

Answer 46

c) temperature perception

Question 47

A pt's eyes jerk while the pt looks to the left. you will record this finding as a) nystagmus b) CN VI palsy c) oculocephalia d) ophthalmic dyskinesia

Answer 47

a) nystagmus

Question 48

The nurse is caring for a pt with peripheral neuropathy who is going to have EMG studies tomorrow morning. The nurse should a) ensure that the pt has an empty bladder b) instruct the pt that there is no risk of electrical shock c) ensure the pt has no metallic jewelry or metal fragments d) instruct the pt that she or he may experience pain during the study

Answer 48

b) instruct the pt that there is no risk of electric shock