Nervous System

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Nervous System

• Brain
• Spinal Cord
• Nerves
• Neurons

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Nervous System Functions

• 1. Sensory incoming signals
• 2. Motor - movement
• 3. Integrative in brain and spinal cord only
  (processors/relay terminals)

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Parts of a Neuron

• Soma cell body
• Dendrite receive messages
• Axon send messages out
• Myelin help speed up messages, made up of
  Schwann cells

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Divisions of the Nervous System

• Central Nervous System
• Peripheral Nervous System
• Somatic
• Autonomic
• Enteric

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Central Nervous System

• Brain
• Spinal Cord
• Control center, coordinates body functions

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Peripheral Nervous System

• Carry messages to and from CNS
• Motor and sensory neurons found here.
• Made of 3 Basic Divisions - Somatic,
  Autonomic, Enteric

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Somatic Nervous Division

• Cranial and spinal nerves
• Reflexes automatic responses to stimuli
• Body Functions sensory and motor

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Autonomic Nervous Division

• Involuntary
• Two divisions
• Sympathetic fight-or-flight responses, speeds
  up reactions
• Parasympathetic counteracts sympathetic,
  returns body to normal, slows down heart rate

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Enteric Nervous Division

• Intestines
• directly controls the gastrointestinal system

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Brain

• Weighs approx. 3 lbs
• 4 parts
• Brain stem
• Diencephalon
• Cerebrum
• cerebellum

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Brain
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Brain Stem 3 parts

• Continuous with spinal cord
• Medulla oblongata
• Midbrain
• Pons (bridge)

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Diencephalon 2 parts

• Thalamus- 80 of diencephalon sorts and edits
  info impulses associated with pain, pressure,
  touch
• Hypothalamus homeostasis
• Control of physical expressions of emotion
• Control of body temp initiates sweating and
  shivering
• Regulation of autonomic nervous system
• Regulation of feeling of hunger or satiety
  (feeling full)
• Control of endocrine system functioning
• Regulation of water balance and thirst
• Regulation of sleep-wake cycles

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Cerebrum

• 4 lobes
• frontal, parietal, temporal, occipital
• Limbic Division emotional brain
• Cerebral Cortex 3 areas
• Sensory, Motor, Association

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Functions of the 4 lobes (add this info under
list of 4 lobes)

• Frontal manages emotions, problem solving,
  reasoning, and planning
• Parietal interpretation of spatial
  relationships between body and other objects
  regulation of personality, numbers, writing
• Temporal interpreting sounds speech, memory,
  reading, emotional responses, auditory responses,
  visual processing, smell
• Occipital processing of vision and color
  recognition

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Cerebral Cortex - Sensory

• Temporal lobe
• Primary visual area - seeing
• Primary auditory area - hearing
• Primary gustatory area - taste
• Primary olfactory area - smell

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Cerebral Cortex - Motor

• Cerebellum
• Primary motor area movement
• Brocas speech area frontal speech
• Agraphia inability to write
• Word deafness inability to understand spoken
  words
• Word blindness inability to understand written
  words

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Cerebral Cortex - Association

• Somatosensory Association Area
• interpret and integrate somatic senses
• Visual Association Area
• past and present visual experiences
• Auditory Association Area
• speech, music, or noise
• Wernickes Area
• translate words into thoughts

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Cerebral Cortex Association cont.d

• Common Integrative Area
• receives, integrates, and relays sensation
  impulses
• Premotor Area
• motor sequences
• - ability to write words
• Frontal Eye Field Area
• controls voluntary scanning movements of the
  eye

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Cerebrum Memory

• Ability to recall thoughts
• Controlled by the Limbic System
• Stored in the temporal lobe
• Short-term memory seconds or hours
• Long-term memory days to years

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Cerebrum 2 hemispheres

• Left Hemisphere
• Controls right side of body, spoken and written
  language, numerical/scientific skills, reasoning
• Right Hemisphere
• Musical, artistic, spatial and pattern
  perception, mental images of sight, sound, touch,
  smell and taste

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Cerebullum

• 2nd largest part of the brain
• Compares intended movements by the motor areas
  with what is actually happening
• Balance and Coordination
• Ataxia disruption of muscle coordination

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Spinal Cord Protection

• 4 layers outside in
• Wall of Vertebral Canal (bone)
• Meninges 3 layers of connective tissues that
  protect the brain and spinal cord
• Dura mater, Arachnoid, Pia mater
• Cerebrospinal Fluid
• Vertebral ligaments

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Meninges

• Dura mater outer, most durable
• Epidural space
• Arachnoid middle, spider web arrangement of
  collagen and elastic fibers
• Pia Mater inner, transparent layer of collagen
  and elastic, adheres to surface of brain and
  spinal cord
• Subarachnoid space where cerebrospinal fluid
  circulates
• Spinal Tap - can be used to administer
  antibiotics, anesthetics and chemotherapy.

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Meninges