Neuro Chapter 47

  1. 2 divisions of the nervous system
    • Central nervous system: brain and spinal cord
    • Peripheral nervous system: nerves of the autonomic nervous system
  2. Neuron cell bodies are found:
    • Brain
    • Spinal cord
    • Trunk of body
  3. Axon
    • Conducts impulses away from the body of the nerve cell
    • Wrapped in Schwann cells (neurolemmocytes)
  4. Dendrite
    Carry nerve impulses toward the cell body of neuron
  5. Myelin
    A phospholipid that electrically insulates neurons from one another.
  6. Oligodendrocytes
    Produce the mylin sheath to electrically insulate neurons of the CNS
  7. Microglia
    Capable of movement and phagocytosis of pathogens and damaged tissue
  8. Astrocytes
    • Contribute to the blood-brain barrier (prevents toxins from diffusing into brain tissue from blood)
    • *a disadvantage is that some useful medications cannot cross the barrier
  9. Ependyma
    • Line the ventricles of the brain
    • Many of the cells are ciliated
    • Involved in production and circulation of cerebrospinal fluid
  10. Synapse
    Small gap between axons of one cell and dendrites of another cell
  11. Afferent neurons
    • Sensory
    • Receptors in the skin, skeletal muscles, and joints are somatic
    • receptors in internal organs are visceral
  12. Efferent Neurons
    • Motor
    • Neurons to skeletal muscle are somatic
    • Smooth muscle, cardiac muscle and glands are visceral and found in ANS
  13. Interneurons
    Found in the CNS and are specialized to transmit sensory or motor impulses or integrate them. Integration is involved in thinking and learning
  14. Gray matter
    Where the cell bodies of motor neurons and interneurons are located.
  15. White matter
    Formed by the myelinated axons
  16. How many pairs of spinal nerves
  17. Spinal nerves (location and #)
    • 8 Cervical
    • 12 Thoracic
    • 5 Lumbar
    • 5 Sacral
    • 1 Coccygeal
  18. 5 parts of Reflex arc (the pathway nerve impulses travel when a reflex is elicited)
    • 1: Receptors detect change and generate impulses
    • 2: Sensory neurons transmit impulses from receptors to CNS
    • 3: CNS contains one or more synapses and interneurons that may be part of pathway
    • 4: Motor neurons transmit impulses from CNS to effector
    • 5: Effector performs action
  19. Spinal cord reflexes include
    • Stretch: a muscle that is stretched automatically contracts
    • Flexor:  Stimulus is something painful and response is to pull away
  20. Cerebellum
    Equilibrium and coordination
  21. Medulla Oblongata
    • Respiratory center, HR, BP
    • Coughing, sneezing, swallowing, vomiting
  22. Occipital lobe
    Vision center
  23. Cerebrum
    • Information storage
    • Right and left hemisphere connected by corpus callosum
  24. Temporal lobe
    • Speech
    • Smell 
    • Hearing
  25. Hypothalamus
    • Production of ADH and oxytocin
    • Regulation of body temp
    • Regulation of food and fluid intake
    • Stimulation of responses in emotional situations
  26. 3 layers of meninges
    • Dura mater: outmost - made of thick, fibrous connective tissue
    • Arachnoid mater: middle - weblike appearance
    • Pia mater: inner - very thin connective tissue on the surface of the brain and spinal cord
  27. Subarachnoid space
    • Between arachnoid and Pia mater
    • Where cerebrospinal fluid circulates
  28. Cerebrospinal fluid
    • Permits exchange of nutrients and wastes between blood and CNS neurons
    • Acts as a cushion for CNS
    • The pressure of fluid can be determined by spinal tap (lumbar puncture)
  29. Sympathetic Nervous system
    • Fight or flight (Stress response)
    • Acetylcholine and noepinephrine
  30. Parasympathetic Nervous system
    • Nonstressful - peaceful
    • Acetycholine activated by acetylinesterase
  31. Basic neurologic assesment
    • 1. Assess level of consciousness
    • 2. Obtain vital signs
    • 3. Check pupillary response to light
    • 4. Determine ability to sense touch or pain in extremeties
  32. First thing to assess in a neurologic examination
    Level of consciousness
  33. Glasgow coma scale assess three parameters
    • 1. eye opening
    • 2. verbal response 
    • 3. motor response
  34. Glascow coma scale in motor response is based on
    • 1. following commands
    • 2. responding to pain
    • 3. abnormal postures
  35. abnormal postures
    • 1. decorticate 
    • 2. decerebrate
    • indicates damage in the area of the brain stem
  36. Decorticate
    flexation, posturing, where patient arm's are flexed at elbow, hands are raised towards chest, and legs are extended.
  37. Decerebrate
    extension, posturing, both arms and legs are extended, arms are internally rotated.
  38. GCS, score of less than 7
  39. GCS, score 15
    fully alert
  40. GCS, score 13 or 14
    mild head injury
  41. GCS, score 9-12
    moderate head injury
  42. GCS, score 8 and below
    severe head injury
  43. Primary causes of delirium or acute states of confusion
    adverse effects of medications
  44. To assess cognitive function, evaluate:
    • patients thinking capacity:
    • -length of attention
    • -ability to concentrate
    • -judgement
    • -memory
    • -perception
    • -problem solving
    • -motor function
  45. Glasgow Coma Scale is used to assess
    Level of consciousness
  46. Mental status examinations are to determine
    • cognitive functioning
    • thought process
    • perception
  47. Anisocoria
    pupils unequal in size
  48. Pupils unequal in size:
    • -may be congenital 
    • -may be caused by cataract surgery 
    • -sudden development of unequal pupils is a emergency and should be reported to physician.
  49. Consensual response, pupils:
    • -when one pupil is exposed to light and the other pupil also constricts.
    • -described as brisk, sluggish, or absent.
    • -difference in speed or size should be reported
  50. Pupil accommodation
    process of focusing from far to near
  51. conjugate gaze
    • eyes move in the same direction in a coordinated manner
    • -(dysconjugate moves in different directions.)
  52. opthalmoplegia
    unable to move eyes in a specific direction
  53. nystagmus
    • -involuntary movement of eyes 
    • -horizontal nystagmus is the most common
    • -common causes include phenytion (dilantin) toxicity and injury to brain stem
  54. 5 point scale for muscle stregnth
    • 5: moves extremity against gravity & resistance of examiner
    • 4: if examiner provides more resistance than patient can overcome
    • 3: if extremity can only work against gravity 
    • 2: extremity needs support 
    • 1:no active movement but muscle contraction can be palpated
    • 0: unable to detect muscular function
  55. reflex grasp assessment
    • -unable to release grasp when told to
    • -reflex palmar grasp may indicate pathological condition of frontal lobe
  56. arm drift assessment
    • -patient raises arms straight with palms upward while eyes are closed.
    • -downward drift or rotation of palm indicates impairment on opposite side of the brain.
  57. plantar flexation
    patient pushes against examiners hand with ball of foot
  58. babinski reflex assessment
    • tested by firmly stroking sole of foot.
    • -normal response = flexation of big toe.
    • -abnormal response = big toe extends, or other toes fan out
  59. romberg's test
    • have pt stand with feet together and eyes closed. 
    • negative romberg's: patient experienced minimal swaying for 20 sec
    • positive romberg's: swaying or leaning to one side. seen in cerebellar dysfunction. (in older adults can be a part of normal aging)
  60. Cushing's triad
    • indicator of intracranial pressure
    • -bradycardia
    • -increasing systolic
    • -irregular respirations
  61. lab tests for underlying cause of neurological symptoms:
    • -thyroid hormone
    • -vitamin b12
    • -complete blood count 
    • -electrolytes
    • -CK
    • -VDRL test
    • -liver and renal function tests
    • -ESR and WBC may indicate infection
    • -hormones such as prolactin or cortisol may indicate pituitary gland dysfunction.
  62. Cerebrospinal fluid
    • -put pt into side laying postion, flex knees to chest
    • - puncture needle placed L3-4 or L4-5
    • -test for glucose, protein, bacteria, levels of immunoglobins, antibodies 
    • - after puncture pt remains on bed rest with head of bed flat for 6-8 hours, increase oral fluids.
    • -assess movement/sensation of lower extremities
  63. disorders detected by CT scan
    • -hemorrhage
    • -altered ventricle size
    • -cerebral atrophy
    • -tumors
    • -skull fractures
    • -abscesses
  64. CT scan prep
    • -ask about allergies (nausea, itching, diaphoresis, difficulty breathing) to contrast material, iodine, shellfish.
    • -BUN and creatinine level checked because contrast material is excreted through kidneys
    • -contrast not use if tumor is suspected 
    • -commonly used as emergency evaluations because ct scans are quick
  65. MRI
    • more detailed picture of soft tissue
    • -used fr diagnosis of multiple sclerosis 
    • -arteriovenous malformations, tumors, hemorrhages, edema.
    • - pace makers or metallic prosthesis, obesity, inability to lay flat or still, clausterphobia are contraindications.
  66. Angiogram
    • x ray study of blood vessles
    • -abnormality of cerebral/spinal blood vessels
    • -info on blood supply to tumor
    • - cath into femoral artery, advanced until contrast can be injected into right vessels
  67. Nursing care for Angiogram
    • before angiogram:
    • -clear liquid diet
    • -iv placed
    • -BUN & creatinine levels evaluated
    • -assess potential for bleeding 
    • During angiogram must lie still
    • after angiogram:
    • -maintain pressure on cath site, and keep bed flat for 6-8 hrs. must keep affected leg straight.
    • -assess vital signs, neuro status, circulation, every 15 min for 1st hour, then every 2 hrs for 4 hrs
  68. mylogram
    • x ray of spinal canal 
    • -contrast material injected into subarachnoid space
    • -patient moved in various positions and radiographs are taken
    • -after procedure bed rest hob less than 30 degrees
  69. electroencephalogram (EEG)
    • electrodes attached to scalp, electrical activity.
    • helps identify abnormalities such as siezure focus.
  70. contractures and footdrop are associated with
    neurologic disorders
  71. contracture
    permanent muscle contraction. cause deformities.
  72. Expressive aphasia
    difficulty or inability to communicate with others
  73. receptive aphasia
    affects patients ability to understand spoken language
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Neuro Chapter 47
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