Divisions of the Nervous System - ANS Central Nervous System (CNS) & Peripheral Nervous System (PNS)
Central Nervous System is Composed of the - ANS brain & spinal cord
Peripheral Nervous System is Composed of - ANS spinal nerves (31 pairs), cranial nerves (12 pairs) &
autonomic nervous system
Autonomic Nervous System is Composed of - ANS - sympathetic (fight or flight) nervous system
-- increase BP, HR, RR, dilate bronchioles & pupils
- parasympathetic (rest or digest) nervous system
-- slows body functions: decreased HR, RR, constricts bronchioles & pupils
-- stimulates salivation
-- contracts bladder & relaxes rectum
- functions are not usually under conscious control
Neurons - ANS - transmits impulses "messages"
- 2 types: motor & sensory
Motor Neurons - ANS neurons that carry outgoing information from the brain & spinal cord to the
muscles & glands causing a purposeful physical movement
Sensory Neurons - ANS neurons that carry incoming information from the sensory receptors to the brain
& spinal cord resulting in the ability to perceive stimulation through one's sensory organs
Myelin Sheaths - ANS - lipid covering
- plays a role in impulse conduction
,- when impaired, impulses cannot travel from the brain to the rest of the body (think pt's w/ MS)
Neuroglial Cells - ANS - provide protection, structure & nutrition for the neurons
- 4 different types (astroglial cells, ependymal cells, oligodendrocytes & microglial cells)
Glial Blastoma - ANS rapid malignant tumor of glial cells w/ a poor prognosis
Layers of the Brain - ANS
Inside the Brain - ANS
Cerebral Cortex - ANS - part of the cerebrum
- processes & communicates all information coming from the PNS
- translates impulses into feelings & thoughts
- divided into 4 lobes: frontal, parietal, temporal & occipital
Cerebellum - ANS - receives immediate & continuous information about the condition of the muscles,
joints & tendons
- controls voluntary movement
- maintain equilibrium (balance)
Brainstem - ANS - includes midbrain, pons & medulla oblongata
- cardiac-slowing center
- respiratory center (pattern or rate)
Circulation of the Brain - ANS - originates from the carotid & vertebral arteries
,- any issues w/ carotid blood flow will cause lack of perfusion to brain
Circle of Willis - ANS a ring at the base of the brain formed by small connecting arteries connected off of
the anterior, middle & posterior cerebral arteries
Cerebral Spinal Fluid - ANS circulates, surrounds & cushions the brain & spinal cord
Spinal Cord - ANS controls mobility, regulates organ function, processes sensory perception info from
extremities, trunks, organs & transmits info to & from brain via descending & ascending tracts
Descending Tracts - ANS - begin in the brain & end in the spinal cord
- autonomic or nonvoluntary movements
Ascending Tracts - ANS - begin in spinal cord & end in brain
- sensation, pain, temperature, light touch/pressure
- awareness of movement
Nursing Assessment - ANS - family history & genetic risk
-- think CVA risk
- personal hx
-- CVA? TIA? AFIB?
- LOC & orientation
- language & copying
- cerebellar function
-- coordinated muscle movement? follows commands?
- memory
, - attention
-- does pt engage w/ eye contact?
- cognition (thought process)
- cranial nerves
- sensory function
- reflex activity
CN I - ANS olfactory (smell)
- sensory
- test by having pt smell scents
CN II - ANS optic (vision)
- sensory
- test: Snellen chart, have pt read text messages
CN III - ANS oculomotor (eye movement)
- motor
- test: 6 cardinal positions of gaze, assess pupil response/constriction
CN IV - ANS trochlear
- motor
- test: observe for unusual eye movements such as strabismus (inward or outward deviation of eye)
CN V - ANS trigeminal
- both