Transcript Central Nervous System Part 2

Central Nervous System Part 2
Cerebrum: lobes, functions, ventricles
Specialization Areas
Cerebral dominance
Disorders
Functions:
• Sensory: interprets signals so
we “know: what we are
seeing, hearing, tasting,
smelling …
• Motor: responsible for all
voluntary movement
(somatic) / some involuntary
(autonomic)
• Association: all intellectual
activities of cerebral cortex:
learning, reasoning, memory
storage, recall, language
abilities, even consciousness
Cerebral cortex: gray matter = cell bodies
of neurons involved in hemisphere functions
Fissure or sulci
Gyri or
gyrus
Ventricles/CSF:
Cerebral white matter:axons
1. association (within hemispheres)
2. commissure –connects
neoccortex of hemispheres
(corpus callosum)
3. projection
Fig. 49-15
Frontal lobe
Parietal lobe
Speech
Frontal
association
area
Somatosensory
association
area
Taste
Reading
Speech
Hearing
Smell
Auditory
association
area
Visual
association
area
Vision
Temporal lobe
Occipital lobe
Central and Limbic lobes
• Frontal: primary motor area allows conscious movement of skeletal
muscles, higher intellectual reasoning, complex memory
• Parietal lobe: somatic sensory area : impulses from sensory
receptors are localized and interpreted; path are X’d, able to
interpret characteristics of objects feel with hand and to comprehend
spoken and written language
• Occipital lobe: visual cortex, receives visual info via thalamus
(primary visual area)integrates info to formulate response (visual
association area)
• Temporal lobe: emotion, personality, memory behavior, auditory and
olfactory area, complex memory (both neo and old cortex)
• Limbic Lobe: (linked with temporal) ring of cortex around cerebral
ventricles, connections between emotional and cognitive
mechanism, emotional, autonomic, subconscious motor and sensory
drives, sexual behavior, biological rhythms
• Motivation=pleasure or punishment
• Limbic is the connection between emotional and cognitive
mechanisms
Basal Nuclei: grey matter deep
within white matter surrounding 3rd
ventricle they influence: monitoring,
starting, stopping of stereotyped
motor movement (voluntary)
1. subconscious movement
2. humans: planning,
programming movement,
information feedback with cortex,
3. help decisions about sensory
Amygdala nucleus: part of the
limbic system located deep within each
hemisphere/ important part of
emotional feelings linked to cognitive
input (pleasure and fear emotions) Fear
conditioning sends input to
hypothalamus to signal the sympathetic
NS to act
Reticular Activating System: nuclei axons connect hypothalamus, thalamus,
cerebellum and spinal cord to keep the cortex alert and conscious. Also acts as a
filter for sensory input to the cortex … filters out 99% of sensory input as
unimportant. RAS: arousal system
Complex polysynaptic path in brainstem
and thalamus RF
Receives messages from neurons on
spine and other parts and communicates
with cerebral cortex with complex circuits
Ultimately responsible for consciousness
Extent of RAS activity determines state of
alertness (focus)
Slow stimulation get sleepy and bored
Toss and turn at night due to RAS
Effects the way we react to stimuli
If damaged= deep permanent coma
Specialization areas: *p 249
primary motor in precentral
gyrus,: motor cortex: control
voluntary skeletal movment
primary sensory in postcentral
gyrus
somatosensory area:: receives
info from skin, joint via thalamus
somatosensory association cortex
Primary somatosensory cortex
Visual association area
Auditory association area
primary visual cortex
primary auditory cortex
auditory association area
olfactory cortex
gustatory cortex
Wernicke’s language area
primary somatic motor cortex:
axons from the primary motor area
in the frontal lobe form major
voluntary motor tract which
descends into the cord, paths are
crossed and body is represented
upside down. Most neurons are
dedicated to fine motor control of
face, moth and hands.
premotor cortex
primary motor area
Spatial Discrimination:
Speech area: junction of parietal
and occipital and temporal lobes:
allows us to understand words,
make connections between words,
in one hemisphere
Broca’s area: base of precentral
gyrus (usually inleft hemisphere)
ability to speak
Prefrontal
Cerebral dominance:
(L) language abilities, mathematics, intellectual functions with language
(R) spatiotemporal matter, recognize face, appreciates and recognizes music
DISORDERS:
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Alzheimers disease
Parkinson’s disease
Stroke
Aphasia
Concussion
Contussion
Cerebral contusion
Disorders and Clinical Applications
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Lumbar puncture
Spinal tap vs epidural
Spina Bifida
Anencaphaply
Paralysis
Spinal Shock
ALS
Poliomyelitis