Neurological System - NUR 204 Exam 3

CNS structure and function

brain and spinal cord

PNS structure and function

all nerve fibers outside brain and spinal cord

• 12 cranial nerves, 31 spinal nerves, and all their branches

• carries sensory (afferent) messages to CNS from sensory receptors

• motor (efferent) messages from CNS to muscles and glands, as well as autonomic messages that govern intern organs and blood vessels

cerebral cortex

Cerebral cortex is center of functions governing thought, memory, reasoning, sensation, and voluntary movement

cerebral cortex

• frontal lobe

personality, behavior, emotions, and intellectual function

• broca’s area in frontal lobe mediates motor speech

cerebral cortex

• parietal lobe

sensation

cerebral cortex

• occipital lobe

visual receptor center

cerebral cortex

• auditory reception center, tase, and smell

Wernicke’s area in temporal lobe associated with language comprehension

damage to cerebral cortex

• motor weakness

• paralysis

• loss of sensation

• impaired ability to understand and process language

damage occurs when highly specialized neurologic cells are deprived of blood supply, such as when a cerebral artery becomes occluded

CNS components

• basal ganglia

Gray matter in two cerebral hemispheres that form subcortical associated motor
system (extrapyramidal system)

CNS components

• thalamus

Main relay station where sensory pathways of spinal cord, cerebellum, and
brainstem form synapses

CNS components

• hypothalamus

Major respiratory center with basic function control and coordination

CNS components

• cerebellum

Concerned with motor coordination and muscle tone of voluntary movements

CNS components

• brainstem

Central core of the brain—contains midbrain, pons and medulla

CNS components

• spinal cord

Main pathway for ascending and descending fiber tracts that connect brain to
spinal nerves

cranial nerves

• 12 pairs of cranial nerves

• supply primarily the head and neck

  • exception is the vagus nerve, which travels to the heart, respiratory muscles, stomach, and gallbladder

• CN I and II extend from cerebrum

• cranial nerves II to XII extend from midbrain and brainstem

level of consciousness (LOC)

• questions to ask

• what is your name?

• where are you?

• what is the date?

dizziness in aging adult

• association with positional change or activity or medication

• impact on ADLs

• safety modifications

memory in aging adult

• decrease in mental function or confusion

• onset, duration, and frequency

tremor in aging adult

• location

• precipitating and alleviating factors

• impact on ADLs

sudden vision changes

• onset, duration, and frequency

• loss of consciousness and safety

• impact on ADLs

cranial nerve I

• olfactory nerve

patency and sense of smell

• close eyes, occlude one nostril and present aromatic substances (familiar smells)

cranial nerve II

• optic nerve

acuity and visual fields

• using ophthalmoscope, examine ocular fundus to determine color, size, shape of optic disc

cranial nerves II, IV, and VI

• oculomotor, trochlear, and abducens nerves

eye movements

• check pupils for size, regularity, equality, direct an consensual light reaction, and accomodation

• assess extraocular movements by cardinal position gaze

• assess for nystagmus

cranial nerve V

• trigeminal nerve

• motor function:

  • assess muscles of mastication by palpating temporal and masseter muscles a person clenches his or her teeth

  • try to separate the jaws by pushing down on chin

• sensory function:

  • with a person’s eyes closed, test light touch sensation by touching a cotton wisp to designated areas on a person’s face

    • forehead, cheeks, and chin

cranial nerve VII

• facial nerve

• motor function:

  • note mobility and facial symmetry

  • have the person puff cheeks, then press puffed cheeks in, to see that air escapes equally from both sides

• sensory function:

  • test sense of taste by applying cotton applicator covered with solution of sugar, salt, or lemon juice tongue and ask the person to identify tast

cranial nerve VIII

• acoustic nerve (vestibulocochlear)

test hearing acuity by ability to hear normal conversation and by whispered voice test

cranial nerve IX and X

• glossopharyngeal and vagus nerves

• motor function:

  • depress tongue with tongue blade, and note pharyngeal movement as the person says “ahhh” or yawns

    • normal: uvula and soft palate should rise in midline, and tonsillar pillars should move medially

  • touch posterior pharyngeal wall with cotton applicatory and note presence of pharyngeal sensations, and void gag reflex

• sensory function:

  • cranial nerve IX does mediate taste on posterior one third of tongue

cranial nerve XI

• spinal accessory nerve

examine sternomastoid and trapezius muscles for equal size and strength

• rotate head against resistance

• shrug shoulders against resistance

cranial nerve XII

• hypoglossal nerve

• inspect tongue and note forward thrust in midline protudes tongue

• ask the person to say “light, tight, dynamite” and note that lingual speech is clear and distince

inspect and palpate motor systems

• muscles

• size

• strength

• tone: normal degree of tension in relaxed muscles (contraction)

• involuntary movements

  • normal: no involuntary movements

coordination and skilled movements

• rapid alternating movements (RAM)

• pat knees with both hands, turn hands over

• finger-to-finger test

• finger-to-nose test

• heel-to-shin test

cerebellar function tests

• balance tests

• gait

  • walking

• tandem walking

  • heel-to-toe

cerebellar function tests

• romberg sign

• stand feet together, hands at side, close eyes

  • falling is a positive romberg sign

• shallow knee bends or hop in place on both legs

anterolateral tracing

• spinothalamic

• pain

  • ability to perceive pinprick

  • break a tongue blade lengthwise, forming a sharp point, lightly apply sharp or dull end to person’s body in random unpredictable order

  • 2 seconds between each stimulus

• light touch

  • apply wisp of cotton to skin in random order of sites and at irregular intervals

  • arms, forearms, hands, chest, thighs, legs

posterior (dorsal) column tract

• vibration

  • ability to feel vibrations of tuning fork over bony prominences and note if gradual or abrupt

• position (kinesthesia)

  • ability to perceive passive movements of extremities

  • eyes closed, move a finger or big toe up and down and ask person to tell you which way it moved

tactile discrimination (fine touch)

• stereognoses

ability to recognize objects by feeling their forms, sizes, and weights

tactile discrimination (fine touch)

• grapesthesia

ability to read a number by having it traced on skin

tactile discrimination (fine touch)

• two-point discrimination

test ability to distinguish separation of two simultaneous pin points on skin

tactile discrimination (fine touch)

• extinction

simultaneously touch both side of body at the same point

• how many sensations were felt and where?

tactile discrimination (fine touch)

• point location

touch skin and withdraw stimulus and ask person to put finger where you touched

deep tendon reflexes

• limn should be relaxed and muscle partially stretched

• short, snappy blow of reflex hammer onto muscle’s insertion tendon with relaxed hold on hammer

• bounce up promptly and do not let hammer rest on tendon

• use flat end when tendon is wider with enough force to get a response

deep tendon reflex 4 point scale

4: very brisk, hyperactive with clonus, disease

3: brisker than average, may indicate disease

2: average, normal

1: diminished, low normal, occurs w reinforcement

0: no response

biceps reflex

• C5 to C6

forearm, place thumb on biceps tendon and strike a blow

• contraction of biceps muscle and flexion of forearm

triceps reflex, C7 to C8

“just go dead” and strike triceps tendon directly just above the elbow

• extension of forearm

brachioradialis reflex, C5 to C6

strike blow to forearm

• flexion and supination of forearm

quadriceps reflex, L2 to L4 (knee jerk)

strike below patella

• extension of lower leg

achilles reflex, L5 to S2 (ankle jerk)

strike Achilles tendon

• foot plantar flexes against your hand

superficial (cutaneous) reflex

sensory receptors in skin rather than in muscles; motor response is at muscle contraction

• babinski reflex

  • normal: inversion and flexion of forefoot

  • abnormal: great toe extension and toes fanning outwards

F.A.S.T. plan

• american stroke association

F: face dropping

A: arm weakness

S: speech difficulty

T: time to call 911

stroke risk factors

• HTN

• cigarette smoking

• heart disorders