nervous system

brain and spinal cord

all nervous structures except the brain and spinal cord

structural and functional unit of the nervous system; nerve cell

neuron interposed between connecting two other neurons

supportive cell of the nervous system; includes microglia, oligodendroglia, and astrocytes

cell process which brings impulses toward the cell body

cell process which takes impulses away from the nerve cell body

• area of functional continuity between neurons; where a nerve impulse is transmitted from one neuron to another
• relaying of info between neurons

sense organs/cells which receive stimuli from the environment

muscles and glands which respond to impulses carried to them by nerves

involuntary, unlearned response to stimuli; a reflex arc consists of an afferent neuron, a central neuron, and an efferent neuron

group of nerve cell bodies outside the CNS (in the PNS)

group of nerve cell bodies within the CNS (brain or spinal cord)

areas in the CNS consisting of nonmyelinated nerve tissue (nerve cell bodies)

substance found in the spinal cord and brain composed of myelinated nerve fibers

intermingling of white and gray matter

• a white fatty material which coats the nerve processes
• insulated the axon and increases the speed of impulses

intersection or crossing

opposite side

same side

• sensations such as:
• pain
• temperature
• touch
• proprioception

these sensations are transmitted to the CNS via sensory tracts and allows the individual to interact with their environment

• frontal (primary motor)
• parietal (primary sensory)
• temporal (primary auditory)
• occipital (primary visual)

• primary motor cortex
• exhibits influence over:
• judgement
• attention
•  mood
• abstract thinking
• agression

• motor region for speech in the frontal lobe
• LEFT= affects movement of mouth for speech
• RIGHT= affects nonverbal communication

contralateral voluntary control of the UEs and facial mvmts

other motor areas, such as the premotor area, control trunk musculature and postural changes. the supplementary motor area controls orientation of the eyes and head, initiation of mvmt and bilateral sequential mvmt

• primary sensory cortex
• perception of sensory info and provides meaning to stimuli
• perceptual learning
• short term memory function
• -person may not like to be touched

• primary auditory cortex
• visual perception
• long term memory
• musical discrimination
• -pt may need increased time and write things down

• in the temporal lobe
• hears and understands spoken language
• pt may not hear or understand

• primary visual cortex
• organization/interpretation of visual info
• eyes take in visual info and send to cortex

left hemisphere-95% of population

• produce written/spoken info
• logical/organized manner
• analytical
• rational
• positive emotions such as love/happiness

• difficulty initiating, sequencing, and processing a task
• apraxia (inability to plan motor tasks)
• difficulting producing or comphrending speech
• anxiety
• perseveration (stuck on one thing, verbal or motor, and repeat it over and over)
• speech or motor behaviors

right hemisphere

• process info in a holistic manner
• process nonverbal stimuli such as designs complex shapes, speech info
• eye-hand coordination
• spatial relationships
• ability to communicate nonverbally
• sustaining posture or mvmt
• perceiving negative emotions such as unhappiness or anger

• poor judgement
• unrealistic expectations
• denial of deficits/disability
• disturbances in body image
• irritability
• fatigue

• homeostasis
• thirst
• hunger
• digestion
• body temp
• BP
• sexual activity
• sleep-wake cycle

limbic system

cerebellum

located below the occiptal lobe

• midbrain -reflex center for auditory, visual, and tactile responses
• pons- reflex center for head orientation in response to auditory or visual stimulation (cranial nerves 5 and 7 are found here)
• medulla- contains motor and sensory nuclei for neck and mouth and control center for heart and respiration rates

• ascending sensory tract that controls pain and temperature
• anterior in the spinal cord

major motor tract; skilled mvmts of extremities that crosses from one side to the other in the brain stem

common sign of damage is the babinski sign

great toe extends and other toes sply when an object or finger is run along the lateral border of the foot

apraxia

somatic

autonomic

maintains homeostasis, regulation of digestion, circulation, and cardiac muscle contraction

CNS

• PNS
• 1.0mm per day depending on the size of the nerve fiber

• found in descending motor tracts within the cerebral cortex
• indicated by spasticity, muscle weakness, hyperreflexia, mild disuse atrophy, abnormal reflexes
• possibilty of clonus

• head inury
• cerebral palsy
• CVA
• MS
• brain tumors

• affects nerves or axons at or below the level of the brain stem
• indicated by abnormal EMG potentials, fasciculations, paralysis, flaccidity, weakening of muscles, absent reflexes, atrophy of skeletal muscles

• spinal cord injury
• trauma
• infection
• poliomyelitis
• spinal cord tumors
• muscular dystrophy

akinesia

inability to perform purposeful learned mvmts, although there is no sensory or motor impairment

ideational apraxia

a person plans a mvmt or task but cant volitionally perform it

ataxia

drunken soldier

mvmt that is very slow

speech is difficult, but comprehension is usually functional or normal

clonus

characteristic of UMN lesion

diplopia

slurred and impaired speech due to motor deficit of the tongue and other muscles essential to speech

dysdiadochokinesia

inability to control the range of a mvmt and the force of muscular activity

pt may over-shoot or under-shoot -> put a weight on them

dysphagia

characteristic of right hemisphere infarct. inability to control emotions and outburts of laughing or crying that are inconsistent with the situation

can receive info but cant express

present with both expressive and receptive deficits. prognosis for recovery with speech is usually poor. pts speech is nonfluent and comprehension is significantly impaired

hemiparesis

hemiplegia

hemianopsia

kinesthesia

inability to interpret stimuli on one side of the body due to a lesion on the other side of the brain

repeatedly performing same segment of a task or repeatedly saying the same word/phrase without a purpose

proprioception

can express but cant receive

state of severe hypertonicity where sustained muscle contraction does not allow for any mvmt for a specific joint

stiffness, but does have a little give

synergy

*uses whole arm to bend elbow

person usual able to verbalize, but is not frequently functional