Neurologic System

During assessment of extraocular movements, two back-and-forth oscillations of the eyes in the extreme lateral gaze occur. This response indicates

an expected movement of the eyes during this procedure. Nystagmus is a back-and-forth oscillation of the eyes. End-point nystagmus, a few beats of horizontal nystagmus at extreme lateral gaze, occurs normally.

The extrapyramidal system is located in the

basal ganglia. The basal ganglia are large bands of gray matter buried deep within the two cerebral hemispheres that form the subcortical associated motor system (the extrapyramidal system).

The _____________ coordinates movement, maintains equilibrium, and helps maintain posture.

cerebellum. The cerebellum controls motor coordination of voluntary movements, equilibrium (i.e., posture balance of the body), and muscle tone. The extrapyramidal system maintains muscle tone and controls body movements, especially gross automatic movements such as walking. The upper motor neurons are located within the central nervous system; influence or modify the lower motor neurons; and include the corticospinal, corticobulbar, and extrapyramidal tracts. The lower motor neurons are located mostly in the peripheral nervous system and extend from the spinal cord to the muscles; examples include the cranial nerves and spinal nerves. The basal ganglia control automatic associated movements of the body.

Clonus that may be seen when testing deep tendon reflexes is characterized by a(n)

set of rapid, rhythmic contractions of the same muscle. Clonus is a set of rapid, rhythmic contractions of the same muscle.

Automatic associated movements of the body are under the control and regulation of

the basal ganglia. The basal ganglia controls automatic associated movements of the body. The thalamus is where sensory pathways of the spinal cord, cerebellum, and brainstem form synapses on their way to the cerebral cortex. The hypothalamus is a major respiratory center with basic vital functions: temperature, appetite, sex drive, heart rate, and blood pressure control; sleep center; anterior and posterior pituitary gland regulation; and coordination of autonomic nervous system activity and stress response. Wernicke's area in the temporal lobe is associated with language comprehension.

What term is used to describe slow, twisting muscle movements that resemble a snake or worm?

Athetosis Athetosis is slow, writhing, continuous, and involuntary movements of the extremities. Ataxia is an impaired ability to coordinate movement, often characterized by a staggering gait and postural imbalance. Flaccid is weak, soft, and flabby; lacking normal muscle tone. Vestibular function is the sense of balance.

The presence of primitive reflexes in a newborn infant is indicative of

immaturity of the nervous system. The nervous system is not completely developed at birth, and motor activity in the newborn is under the control of the spinal cord and medulla. The neurons are not yet myelinated. Movements are directed primarily by primitive reflexes. As the cerebral cortex develops during the first year, it inhibits these reflexes, and they disappear at predictable times. Persistence of the primitive reflexes is an indication of central nervous system dysfunction.

An abnormal sensation of burning or tingling is best described as

paresthesia. Paresthesia is an abnormal sensation such as burning or tingling. Paralysis is a loss of motor function as a result of a lesion in the neurologic or muscular system or loss of sensory innervation. Paresis is a partial or incomplete paralysis. Paraphasia is a condition in which a person hears and comprehends words but is unable to speak correctly; incoherent words are substituted for intended words.

Cerebellar function is tested by

performance of rapid alternating movements. The cerebellum controls motor coordination of voluntary movements, equilibrium, and muscle tone. Cerebellar function is tested by balance tests (e.g., gait, Romberg test) and coordination and skilled movements (e.g., rapid alternating movements, finger-to-finger test, finger-to-nose test, heel-to-shin test). Muscle strength assessment examines the intactness of the motor system. The Phalen maneuver reproduces numbness and burning in a patient with carpal tunnel syndrome. Superficial pain and touch assessment examines intactness of the spinothalamic tract.

Testing the deep tendon reflexes gives the examiner information regarding the intactness of the

reflex arc at specific levels in the spinal cord. Measurement of the deep tendon reflexes reveals the intactness of the reflex arc at specific spinal levels. The corticospinal tract is the higher motor system that permits very skilled and purposeful movements such as writing. The medulla contains all ascending and descending fiber tracts; it has vital autonomic centers for respiration, heart, and gastrointestinal function as well as nuclei for cranial nerves VIII through XII. The upper motor neurons are located within the central nervous system and influence or modify the lower motor neurons and include the corticospinal, corticobulbar, and extrapyramidal tracts. The lower motor neurons are located mostly in the peripheral nervous system and extend from the spinal cord to the muscles; examples include the cranial nerves and spinal nerves.