Chp 24

The two parts of the nervous system are the:

• Motor and sensory.

• Central and peripheral.

• Peripheral and autonomic.

• Hypothalamus and cerebral.

Answer explanation

The nervous system can be divided into two partscentral and peripheral. The central nervous system includes the brain and spinal cord. The peripheral nervous system includes the 12 pairs of cranial nerves (CNs), the 31 pairs of spinal nerves, and all of their branches.

Which of these statements about the peripheral nervous system is correct?

• The CNs enter the brain through the spinal cord.

• Efferent fibers carry sensory input to the central nervous system through the spinal cord.

• The peripheral nerves are inside the central nervous system and carry impulses through their motor fibers.

• The peripheral nerves carry input to the central nervous system by afferent fibers and away from the central nervous system by efferent fibers.

Answer explanation

A nerve is a bundle of fibers outside of the central nervous system. The peripheral nerves carry input to the central nervous system by their sensory afferent fibers and deliver output from the central nervous system by their efferent fibers. The other responses are not related to the peripheral nervous system.

A 21-year-old patient has a head injury resulting from trauma and is unconscious. There are no other injuries. During the assessment what would the nurse expect to find when testing the patients deep tendon reflexes?

• Reflexes will be normal.

• Reflexes cannot be elicited.

• All reflexes will be diminished but present.

• Some reflexes will be present, depending on the area of injury.

Answer explanation

A reflex is a defense mechanism of the nervous system. It operates below the level of conscious control and permits a quick reaction to potentially painful or damaging situations.

A 70-year-old woman tells the nurse that every time she gets up in the morning or after shes been sitting, she gets really dizzy and feels like she is going to fall over. The nurses best response would be:

• Have you been extremely tired lately?

• You probably just need to drink more liquids.

• Ill refer you for a complete neurologic examination.

• You need to get up slowly when youve been lying down or sitting.

Answer explanation

Aging is accompanied by a progressive decrease in cerebral blood flow. In some people, this decrease causes dizziness and a loss of balance with a position change. These individuals need to be taught to get up slowly. The other responses are incorrect.

During the taking of the health history, a patient tells the nurse that it feels like the room is spinning around me. The nurse would document this finding as:

• Vertigo.

• Syncope.

• Dizziness.

• Seizure activity.

Answer explanation

True vertigo is rotational spinning caused by a neurologic dysfunction or a problem in the vestibular apparatus or the vestibular nuclei in the brainstem. Syncope is a sudden loss of strength or a temporary loss of consciousness. Dizziness is a lightheaded, swimming sensation. Seizure activity is characterized by altered or loss of consciousness, involuntary muscle movements, and sensory disturbances.

A 50-year-old woman is in the clinic for weakness in her left arm and leg that she has noticed for the past week. The nurse should perform which type of neurologic examination?

• Glasgow Coma Scale

• Neurologic recheck examination

• Screening neurologic examination

• Complete neurologic examination

Answer explanation

The nurse should perform a complete neurologic examination on an individual who has neurologic concerns (e.g., headache, weakness, loss of coordination) or who is showing signs of neurologic dysfunction. The Glasgow Coma Scale is used to define a persons level of consciousness. The neurologic recheck examination is appropriate for those who are demonstrating neurologic deficits. The screening neurologic examination is performed on seemingly well individuals who have no significant subjective findings from the health history

During an assessment of the CNs, the nurse finds the following: asymmetry when the patient smiles or frowns, uneven lifting of the eyebrows, sagging of the lower eyelids, and escape of air when the nurse presses against the right puffed cheek. This would indicate dysfunction of which of these CNs?

• Motor component of CN IV

• Motor component of CN VII

• Motor and sensory components of CN XI

• Motor component of CN X and sensory component of CN VII

Answer explanation

The findings listed reflect a dysfunction of the motor component of the facial nerve (CN VII).

The nurse is testing the function of CN XI. Which statement best describes the response the nurse should expect if this nerve is intact? The patient:

• Demonstrates the ability to hear normal conversation

• Sticks out the tongue midline without tremors or deviation.

• Follows an object with his or her eyes without nystagmus or strabismus

• Moves the head and shoulders against resistance with equal strength.

Answer explanation

The following normal findings are expected when testing the spinal accessory nerve (CN XI): The patients sternomastoid and trapezius muscles are equal in size; the person can forcibly rotate the head both ways against resistance applied to the side of the chin with equal strength; and the patient can shrug the shoulders against resistance with equal strength on both sides. Checking the patients ability to hear normal conversation checks the function of CN VIII. Having the patient stick out the tongue checks the function of CN XII. Testing the eyes for nystagmus or strabismus is performed to check CNs III, IV, and VI.

When the nurse asks a 68-year-old patient to stand with his feet together and arms at his side with his eyes closed, he starts to sway and moves his feet farther apart. The nurse would document this finding as:

• Ataxia.

• Lack of coordination.

• Negative Homans sign.

• Positive Romberg sign.

Answer explanation

Abnormal findings for the Romberg test include swaying, falling, and a widening base of the feet to avoid falling. A positive Romberg sign is a loss of balance that is increased by the closing of the eyes. Ataxia is an uncoordinated or unsteady gait. Homans sign is used to test the legs for deep-vein thrombosis.

During an assessment of a 22-year-old woman who sustained a head injury from an automobile accident 4 hours earlier, the nurse notices the following changes: pupils were equal, but now the right pupil is fully dilated and nonreactive, and the left pupil is 4 mm and reacts to light. What do these findings suggest?

• Injury to the right eye

• Increased intracranial pressure

• Test inaccurately performed

• Normal response after a head injury

Answer explanation

In a person with a brain injury, a sudden, unilateral, dilated, and nonreactive pupil is ominous. CN III runs parallel to the brainstem. When increasing intracranial pressure pushes down the brainstem (uncal herniation), it puts pressure on CN III, causing pupil dilation. The other responses are incorrect.