Nervous System PDF

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Lecture notes for the nervous system...

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Neurologic System Nervous System  OLD CART ICE o Onset, location, duration o Characteristics, aggregating factors, relieving factors, treatment o Impact on ADL, coping, emotional response  Structures of the brain o Cerebral Cortex – center of functions governing thought, memory, reasoning, sensation and voluntary movement  Frontal Lobe – personality, behavior, emotions, intelligence  Parietal Lobe – sensation  Occipital – vision  Temporal – auditory, taste, and smell  Wernicke’s – language comprehension  Broca’s – motor speech o Basal ganglia – initiates & coordinates movement, automatic movements of body o Thalamus – relay station for sensory pathway o Hypothalamus – respiratory center for appetite, sex drive, temp, HR, BP, sleep, emotions Cerebellum – coordination of voluntary movements, equilibrium, and muscle tone (≠initiate but coordinates smooth movements) o Brain Stem  CN 3-8 originates in brain stem  Midbrain, pons, medulla (vital autonomic center – respiration, heart, GI) Pathways of CNS o Crossed nerve tracts  left cortex receives and controls function on right (vice versa) o

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Body parts correlate with brain map   No felt image “referred pain” (heart = chest, shoulder, L arm, spleen = left shoulder) o Motor pathways  Corticospinal or Pyramidal Tract - voluntary movement (skilled, discrete, purposeful)  Extrapyramidal – include motor fibers from motor cortex, basal ganglia, brain stem, spinal cord  Subcortical – muscle tone, body movement, gross automatic movement (walking)  Cerebellar – equilibrium & posture Upper and lower motor neurons o Upper – located within CNS  Disease example: CVA, cerebral palsy, multiple sclerosis o Lower – located in anterior gray column of spinal cord  Disease example: spinal cord lesions, poliomyelitis, ALS Reflex Arc (to dorsal ganglion in spine & back) o Involuntary – quick rxn to potentially painful or damaging situations  Deep tendon reflex 4 Brisk, hyperactive with clonus, indicative of disease 3 Brisker than average 2 Average, normal 1 Diminished, low normal, occurs with reinforcement 0 No response  Biceps reflex: C5 – C6 o Support forearm, place thumb on bicep tendon, stroke blow to thumb o Normal: contraction bicep & flexion of forearm  Brachioradialis reflex: C5 – C6 o Hold person’s thumb to suspend forearm, strike 2-3 cm above radial styloid process o Normal: flexion & supination of forearm  Triceps reflex: C7 – C8 o Let arm “go dead”, strike to triceps tendon directly above elbow o

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Neurologic System

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Cranial nerves – enters & exits from the brain o CN I & II  extend from cerebrum o CN III = XII  extend from lower diencephalon & brain stem o CN I – Olfactory (smell)  *Ansomia = loss sense of smell o CN II – Optic (visual acuity)  Use ophthalmoscope to determine color, size, shape of optic disc o CN III – Oculomotor (eye movement)  *Adie’s pupil – large dilated pupil  *Tonic pupil – slow constriction (page 315, table 14-4)  *Doll’s eye – coma patient  move opposite of head = brain stem functional  negative o CN IV – Trochlear (eye movement: SO4) o CN V – Trigeminal  Motor: Teeth clench (TMJ)  Sensation: cotton wisp to eyes, forehead, cheeks, chin o CN VI – Abducens (eye movement: LR6)  Nystagmus – back & forth oscillation of eyes o CN VII – Facial  Motor: smile, frown, close eyes, show teeth, puff cheeks 

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Infants 

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o Normal: extension of forearm Quadriceps reflex: L2-L4 Achilles reflex: L5 – S2 o Knees flexed, hold foot in dorsiflexion, strike Achilles tendon directly o Normal: foot plantar against hand Superficial (cutaneous) reflex  Ab reflex (upper = T8-T10), (lower = T10-T12) o Localized muscle contraction: tickling abs Cremasteric reflex: L1-L2 o Stroke inner thigh, elevation of ipsilateral testicle Plantar reflex: L4 – S2 (Babinski)

Sensory: taste to anterior 2/3 tongue (not tested often)

 *Chovastek sign – twitch in cheek from tap (hypocalcemia) o CN VIII – Acoustic (hearing) o CN IX – Glossopharyngeal & CN X – Vagus  Motor: uvula movement, gag reflex  Sensory: posterior 1/3 tongue (not tested often) o CN XI – Spinal (head, neck & shoulders)  Shrug shoulders o CN XII – Hypoglossal (tongue) Spinal nerves – 31 spinal nerves o 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal o Dermal segmentation overlaps (one can help control other)  Thumb (C6), Middle finger (C7), Pinky (c8)  Axilla (T1), Nipple (T4), Umbilicus (T10)  Groin (L1), Knee (L4)  Page 628 Jarvis Developmental Competence o 2 months – smile & recognize parent’s face o 4 months – babbling o 7-9 months – localize stimulus & show signs of withdrawal Reflex:

Neurologic System o o o o o

Rooting (brush cheek, turns and opens mouth), grasp, tonic neck, moro, Palmar (tight grasp of baby fingers), Plantar (toes curl down tightly w/ touch), Tonic (head to one side, ipsilateral extension of arm and leg) Moro (falling reflex)

Aging Adult  Over 65+ = general loss of muscle (tone in face, neck, spine), impaired fine coordination & agility, loss of vibratory sense, irregular pupil shape, ↓ pupillary reflex  ↓ Reaction time, ↓ Cerebral blood flow  dizziness & loss of balance  ↓ sensation touch, pain, taste, and smell  Senile tremors – intention tremor of hands, head nodding, tongue protrusion Cerebellar Function  Gait: walk 10 – 20ft, walk heel-to-toe, walk on toes, walk on heels  Romberg test: stand feet together, arms to side, close eyes, hold for 20 seconds  Rapid Alternating Movements: path knees with palm then dorsal, touch thumb to finger, finger-to-nose, heel-to-shin Sensory System  Routine testing: superficial pain, light touch & vibration  Complete testing: if patient has neurologic symptoms  Spinothalamic tract o Pain, Temperature, Light Touch  Posterior column tract o Vibration – tuning fork over bony prominences o Kinesthesia – perceive passive movements  eyes closed, arm up or down? o Tactile discrimination (fine touch)  Stereognosis – recognize objects by feeling  Graphesthesia – “read” a number by tracing on skin  Two-point discrimination – distinguish separation of 2 simultaneous pin points on skin  Extinction – simultaneously touch both side of body at same time  Point location – touch skin & withdraw, ask person to point where touched Abnormal Muscle Movement  Chorea – brief, sudden, purposeless movements of body  Fasciculation – brief, spontaneous contraction of muscle fibers  flicker under skin  Tic – spasmodic contraction of muscle mostly in face  Myoclonus – jerky contraction of groups of muscle  Athetosis – involuntary twisting, squirming (usually hands & fingers) page 671, table 23-5 Abnormal gaits  Spastic hemiparesis – circumduction with affected side  Cerebellar ataxia – lack coordination, lean towards side with lesion  MS, stroke, intoxicate, phenytoin  Parkinsonian – hard initiating walk, shuffling steps (fenestrated)  Steppage or footdrop – raising the thigh up and exaggerated walking to avoid tipping on toes o Have pt walk on toes: If can’t = Indicates weakness of gastrocnemius  Scissoring – spastic paraparesis  MS, spinal cord compression Abnormal posture  Opishotonos – arching back, head & heels bent backwards  meningeal irritation o Kernig’s Test – flex knee and hip to 90 degrees, slow extension up (pain) o Brudzinski’s Test – flex patient’s next upwards (flex hips & legs)

Neurologic System...