PA 2008-PD Chapter 17 Cranial nerves
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- Which CN arise from the diencephelon and brainstem
- CN 2 and 12
- How many peripheral nerves in body
- 31 pairs attached to spinal chord, 8C, 12T, 5T, 5S, 1Coccygeal
- Anterior(ventral) and Posterior(dorsal), sensory or motor?
- Ant. motor and posterior sensory
- Is the sensory fiber afferent or efferent?
- Afferent (away from the peripheral)
- What does gray matter contain?
- aggregations of nerve cell bodies
- What is a deep tendon reflex?
- Muscle stretch reflexes that are relayed over structures of both the central and peripheral nervous system
- What is a reflex?
- Involuntary stereotypical response that may involve as few as 2 neurons, one afferent(sensory) and one efferent (motor)across a synapse
- Deep tendon reflexes in arms and legs are?
- Monosynaptic reflexes
- To elicit a deep tendon reflex?
- tap tendon of partially stretched muscle
- In order for deep tendon reflex to fire what component must be intact?
- Reflex arc component
- What are the components of the reflex arc?
- sensory nerve fibers, spinal cord synapse, motor nerve fibers, neuromuscular junction, muscle fibers
- Segmental levels of deep tendon reflex in acending order from ankle to triceps
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Ankle reflex= S1
Knee reflex= L2,3,4
Supinator(brachioradialis)= C5,6
Biceps= C5,6
Triceps= C6,7 - Reflexes that can stimulated from stroking the skin
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Abdominal reflex- upper T8,9,10 lower- T10,11,12
Plantar responses- L5,S1 - 3 kinds of motor pathways
- Corticospinal tract, basal ganglia system, cerebellar system
- Corticospinal tract
- Mediate voluntary movement and integrate skill, complicated, or dedicated movements by selective muscular actions and inhibiting others. Inhibits muscle tone, originates in the motor cortex
- Basal ganglia system
- Maintains muscle tone, controls body movement, gross autonomic movements ex:walking
- Cerebellar system
- Sensory and motor input. Coordinates motor activity, maintains equilibrium, controls posture
- If there is a Upper motor neuron(UMN) lesion above crossover of its tracts in the medulla
- Motor impairment on the contralateral side (opposite side)
- If UMN lesion below the crossover of its tracts
- ipsilateral side (same side)
- UMN lesions manifestations
- decreased muscle tone, deep tendon reflex exaggerated
- Basal ganglia damage
- increase muscle tone, disturbance in posture and gait, bradykinesia, involuntary movements
- Cerebrum damage
- impairs coordination, gait and equilibrium, and decreased muscle tone
- What do sensory impulses do?
- give rise to conscious sensation, calibrate body position in space, regulate BP, HR, and respiration
- 2 Sensory pathways?
- Spinothalamic tracts and Posterior columns
- Spinothalamic tract?
- Pain and temp. Crude touch-light touch without localization
- Posterior columns?
- Position and vibration, fine touch
- What are dermatomes?
- band of skin innervated by the sensory root of a single nerve
- Dermatomes of front and back of neck?
- C3
- Dermatome of thumb, ring and little finger?
- C6, C8
- Dermatome of nipples, umbilicus and inguinal?
- T4, T10, L1s
- Dermatomes of the Knee?
- L4
- Dermatome of the anterior ankle and foot, and plantar foot
- L5
- Dermatome of the perianal region
- S5
- The two most common symptoms in neurologic disorders?
- Headache and dizziness(see table 6-1 pg. 206-209)
- Subarachnoid headache?
- "worst headache of my life"
- Dull headaches?
- Affected by coughing, sneezing, or sudden head movements. Recurrent in same location, is seen with mass lesions like brain tumors
- In what neurologic disorder is diplopia, dysarthria, and ataxia seen?
- TIA's or strokes
- Where do focal weakness arise from?
- From ischemic, vascular, or mass lesions in the CNS,also form PNS disorders, neuromuscular disorders, and muscles
- Bilateral proximal weakness in what disorder?
- Myopathy
- Bilateral distal weakness
- Polyneuropahty
- Weakness made worse with repeated effort and improved with rest suggest?
- Myasthenia gravis
- Paresthesias in hands and around the mouth as a result of what disorder?
- Hyperventilation
- Young people with emotional stress and warning symptoms of flushing, warmth, or nausea may have?
- Vasodepressor (vasovagal) syncope
- Cardiac syncope
- More common in older patients
- Tonic-clonic motor activity, bladder or bowel incontinence, and postictal state suggest?
- Generalized seizure
- CN I
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Olfactory- sensory
Smell - CN II
- Vision- sensory
- CN III
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Oculomotor-motor
pupillary constriction, opening of eyes, and extraocular movements - CN IV
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Trochlear-motor
Downward-inward eye movement - CN V
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Trigeminal-both
Motor-temporal and masseter muscles(jaw clenching), lateral movements of jaw
Sensory-opthalmic, maxillary, mandibular - CN VI
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Abducens-motor
Lateral deviation of eyes - CN VII
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Facial-both
Motor-facial expressions, closing of eyes and mouth
Sensory-taste on the anterior two thirds of tongue - CN VIII
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Vestibulo-cochlear-sensory
Hearing and balance - CN IX
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Glossopharyngeal
Motor-pharynx
Sensory-posterior portions of eardrum and ear canal and tongue, pharynx - CN X
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Vagus-
Motor-palate, pharynx, larynx
Sensory-pharynx and larynx - CN XI
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Accessory- motor
SCM and trapezius - CN XII
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Hypoglossal-motor
tongue