Chapter 7 - Neurological System Disorders Flashcards
Upper Motor Neurons
Structures: Any nerve cell body or nerve fiber in the spinal cord (except the anterior horn cells), all superior structures (gray & white matter affecting motor functions and descending nerve tracts), cranial nerve nuclei
Lesion Symptoms: Increased deep tendon reflexes, spasticity, clonus, emergence of primitive reflexes including Babinski’s sign, exaggerated cutaneous reflexes, autonomic dysreflexia, flaccidity may occur at the level of the lesion.
Lower Motor Neurons
Peripheral Nerves
Structures: Cell bodies in the anterior horn of the spinal cord, spinal nerves, the cranial nerve fibers that travel to target muscles.
Lesion Symptoms: Flaccidity, decreased or absent deep tendon reflexes, atrophy
Left Hemisphere of Brain
Movement of R side, processing of sensory information from R side, visual reception from R field, visual verbal processing, bilateral motor praxis, verbal memory, bilateral auditory reception, speech, and processing of verbal auditory information
Right Hemisphere of Brain
Movement and processing of sensory information from L side, visual reception from L field, visual spatial processing, L motor praxis, nonverbal memory, attention to incoming stimuli, emotion, processing of nonverbal auditory information, and interpretation of abstract information and tonal inflections
Frontal Lobe
Primary motor cortex for voluntary muscle activation
Controls emotions, judgements, higher order cognitive functions
Related to planning of movements including Broca’s Area - controls motor aspects of speeh
Parietal Lobe
Primary sensory cortex for integration of sensation
Receives fibers conveying touch, proprioceptive, pain and temperature sensations from opposite sides of the body
Temporal Lobe
Receives/Processes auditory stimuli
Language comprehension: Wernicke’s Area
Limbic System
Concerned with instincts and emotions contributing to perseveration of the individual
- includes feeding, aggression, emotions, endocrine aspects of sexual response, and long term memory
Occipital Lobe
Receives and processes visual stimuli
Dorsal columns/medial lemniscal system
White matter - Ascending
Sensations of proprioception, vibration, and tactile discrimination; divided into UE and LE tracts, and cross at medulla to form medial lemniscus
Spinothalamic tracts
White matter - Ascending
Convey pain, temperature and crude touch; tracts ascend a few spinal cord segments ipsilaterally and then cross to opposite side
Spinocerebellar tracts
White matter - Ascending
Convey proprioception information and touch and pressure to cerebellum for control of voluntary movements
Dorsal ascends ipsilaterally to cerebellar peduncle
Ventral ascends contralaterally and ipsilaterally to superior cerebellar peduncle
Spinoreticular tracts
White matter - Ascending
Convey deep and chronic pain to reticular formation of brain stem via diffuse polysynaptic pathways
Corticospinal Tracts
White matter - descending
Cross in medulla (pyramidal decussation), 10% of fibers do not cross
Important for voluntary motor control
Vestibulospinal Tracts
White matter - descending
Descend both crossed and uncrossed; important for control of muscle tone, antigravity muscles, and postural reflexes.
Rubrospinal Tract
White matter - descending
Assists in motor function
Reticulospinal System
White matter - descending
Descends both crossed and uncrossed
Modifies transmission of sensation, especially pain
Influences gamma motor neurons and spinal reflexes
Tectospinal Tract
White matter - descending
Assists in head turning responses in response to visual stimuli
Middle Cerebral Artery stroke
Internal Carotid Artery similar symptoms
Contralateral hemiplegia, hemianesthesia, homynymous hemianopsia, aphasia and/or apraxia (usually L MCA), unilateral neglect and spatial dysfunction (usually R MCA)
Anterior Cerebral Artery Stroke
Contralateral hemiplegia, grasp reflex, incontinence, confusion, apathy and mutism
Posterior Cerebral Artery Stroke
Homonymous hemianopsia, thalamic pain, hemisensory loss and/or alexia
Vertebrobasilar System Stroke
Results in pseudobulbour signs (dysarthia, dysphagia, and emotional instability) tetraplegia
CN I
Olfactory
Sensory: carries impulse for smell
Test: ask person to sniff various aromatic substances
CN II
Optic
Sensory: carries impulses for vision
Test: eye chart, visual field testing
CN III
Oculmotor
Motor: fibers to the superior, inferior, and medial rectus muscles of the eye and to the smooth muscle controlling lense shape, medial and vertical eye movements
Sensory: Proprioception of the eye
Test: pupil sizes compared for shape and equality, pupillary reflex is tested; visual tracking tested
CN IV
Trochlear
Proprioceptor and motor fibers for superior oblique muscles of the eye - down/inward eye movement
Test: tested with CN III relative to following eye movement
CN V
Trigeminal
Motor and sensory for face, conducts sensory impulses from mouth, nose, eyes; motor fibers for muscles of mastication. Control of jaw movements
Test: Pain, touch, temp. with proper stimulus; corneal reflex is tested with a wisp of cotton; person is asked to move jaw through full ROM
CN VI
Abducens
Motor and proprioceptor fibers to/from lateral rectus muscle. Lateral eye movements
Test: In conjunction with CN III relative to lateral eye movements
CN VII
Facial
Mixed sensory and motor - sensory fibers to taste buds and anterior 2/3 tongue; motor fibers to muscles of facial expression and to salivary glands
Test: Symmetry of face - ask to make different faces
Sweet, salty, bitter substances applied to tongue to test tasting ability
CN VIII
Vestibulocochlear
Sensory: Transmits impulses for senses of equilibrium and hearing
Test: Hearing checked with tuning fork
CN IX
Glossopharyngeal
Motor fibers for pharynx and salivary glands; sensory fibers for pharynx and posterior tongue. Taste sensation for sweet, bitter, and sour
Test: Gag and swallow reflexes; posterior 1/3 tongue tested for taste
CN X
Vagus
Sensory/motor impulses for larynx and pharynx; parasympathetic motor fibers supply smooth muscles of abdominal organs; sensory impulses from viscera
Test: in conjunction with IX
CN XI
Spinal Accessory
Sensory/motor fibers for sternocliedomastoid, trapezius muscles, muscles of soft palate, pharynx and larynx.
Movement of the neck and shoulders
Test: sternocliedomastoid and trapezius muscle tests
CN XII
Hypoglossal
Motor/sensory fibers to/from tongue; tongue movement
Test: stick tongue out; note abnormalities
