Download Nervous System Pt 3

Write this down…
 Homework 2 Study Guide (Synapses)
 Due at the beginning of lab this week
 Front and back
 TASS
 M&W 1-2pm Willamette Hall 204
Thought Question…
 When you have one of your mandibular teeth worked
on at the dentist and he gives you a shot to deaden
half of your mouth, what division of the nervous
system is being affected by the lidocaine?
 What do you think it’s mode of action is?

Hint: Remember Physio-EX in lab?
 Is it affecting a cranial or spinal nerve?
The Nervous System
THE CENTRAL NERVOUS SYSTEM,
THE BRAIN
Introduction
 Integration
 Memory
 Learning
 Sensation and perception
Neural Tissue - Definitions
 White matter versus Gray matter
 Fiber Bundles
 Nerves versus Tracts
 Nerve Cell Bodies
 Nucleus versus Ganglion
White and Gray Matter
Central cavity surrounded by a gray matter core
 External white matter composed of myelinated fiber
tracts
 Brain has additional areas of gray matter not present
in spinal cord

Cortex of
gray matter
Inner gray
matter
Central cavity
Migratory
pattern of
neurons
Cerebrum
Cerebellum
Region of cerebellum
Outer white
matter
Gray matter
Central cavity
Inner gray matter
Outer white matter
Brain stem
Gray matter
Central cavity
Outer white matter
Spinal cord
Copyright © 2010 Pearson Education, Inc.
Inner gray matter
Figure 12.4
Brain
Similar pattern with additional areas of gray matter
The Brain
 Conscious perception
 Internal regulation
 Average adult male 3.5 lbs
 Average adult female 3.2 lbs
Same brain mass
to body mass ratio!
Brain Regions

4 Adult brain regions
1. Cerebral hemispheres (cerebrum)
2.
3.
4.
Diencephalon
Cerebellum
Brain stem (midbrain, pons, and medulla)
Brain Regions
Figure 12.3d
Ventricles
 Four major regions are connected by ventricles and aqueducts
Figure 12.5
Ventricles
 Filled with cerebrospinal fluid
 Lined by ependymal cells
 Continuous with one another
Cerebrum
 Cerebral hemispheres form superior part of brain
 About %80 of brain mass
 3 tissue layers
 Superficial cortex, gray matter
 Internal white matter
 Basal nuclei, islands of gray matter
Anterior
Longitudinal
fissure
Frontal lobe
Cerebral veins
and arteries
covered by
arachnoid
mater
Parietal
lobe
Right cerebral
hemisphere
Occipital
lobe
Left cerebral
hemisphere
(c)
Posterior
Figure 12.6c
Cerebral Cortex
 Surface layer of cerebrum
 ―Executive Suite‖
 Convolutions
 Gyri – elevated ridges
 Sulci – shallow grooves
 Fissures – deep grooves, separate larger regions of the brain
Cerebrum
 Fissures divide cerebral hemispheres into 4 lobes
Functional Areas of the Cerebral Cortex
 The three types of functional areas are:
 Motor areas—control voluntary movement
 Sensory areas—conscious awareness of sensation
 Association areas—integrate diverse information
 Contralateral orientation
 Hemispheres are functionally specialized
 Conscious behavior involves the entire cortex
Cerebral Motor Activity
Motor areas
Central sulcus
Primary motor cortex
Premotor cortex
Frontal eye field
Broca’s area
(outlined by dashes)
Prefrontal cortex
Working memory
for spatial tasks
Executive area for
task management
Working memory for
object-recall tasks
Solving complex,
multitask problems
(a) Lateral view, left cerebral hemisphere
Sensory areas and related
association areas
Primary somatosensory
cortex
Somatic
Somatosensory
sensation
association cortex
Gustatory cortex
(in insula)
Taste
Wernicke’s area
(outlined by dashes)
Primary visual
cortex
Visual
association
area
Auditory
association area
Primary
auditory cortex
Vision
Hearing
Motor association cortex
Primary sensory cortex
Primary motor cortex
Sensory association cortex
Multimodal association cortex
Figure 12.8a
Primary Motor Cortex
 Large pyramidal cells of the precentral gyrus
 Long axons  pyramidal (corticospinal) tracts
 Allows conscious control of precise, skilled,
voluntary movements
 Motor homunculi: upside-down caricatures
representing the motor innervation of body regions
Motor Homunculus
Somatotopy of precentral
gyrus (primary motor cortex)
Posterior
Motor
Motor map in
precentral gyrus
Anterior
Toes
Jaw
Tongue
Swallowing
Primary motor
cortex
(precentral gyrus)
Figure 12.9
Premotor Cortex
 Anterior to the precentral gyrus (primary motor cortex)
 Controls learned, repetitious, or patterned motor
skills
 Coordinates simultaneous or sequential actions
 Involved in the planning of movements that depend
on sensory feedback
Broca’s Area
 Anterior to the inferior region of the premotor area
 Present in one hemisphere (usually the left)
 A motor speech area that directs muscles of the
tongue
 Is active as one prepares to speak
Frontal Eye Field
 Anterior to the premotor cortex and superior to
Broca’s area
 Controls voluntary eye movements
Cerebral Motor Activity
Motor areas
Central sulcus
Primary motor cortex
Premotor cortex
Frontal eye field
Broca’s area
(outlined by dashes)
Prefrontal cortex
Working memory
for spatial tasks
Executive area for
task management
Working memory for
object-recall tasks
Solving complex,
multitask problems
(a) Lateral view, left cerebral hemisphere
Sensory areas and related
association areas
Primary somatosensory
cortex
Somatic
Somatosensory
sensation
association cortex
Gustatory cortex
(in insula)
Taste
Wernicke’s area
(outlined by dashes)
Primary visual
cortex
Visual
association
area
Auditory
association area
Primary
auditory cortex
Vision
Hearing
Motor association cortex
Primary sensory cortex
Primary motor cortex
Sensory association cortex
Multimodal association cortex
Figure 12.8a
Cerebral Vascular Accident (Stroke)
 Types
 Ischemic stroke
 Hemorrhagic stroke
 Result
 Tissue death called an infarct
 Effects are determined by where and how large an area is
involved
Stroke cont.
Stroke cont.
Cerebral Sensory Activity
Motor areas
Primary motor cortex
Premotor cortex
Frontal eye field
Central sulcus
Sensory areas and related
association areas
Broca’s area
(outlined by dashes)
Prefrontal cortex
Working memory
for spatial tasks
Executive area for
task management
Working memory for
object-recall tasks
Solving complex,
multitask problems
(a) Lateral view, left cerebral hemisphere
Primary somatosensory
cortex
Somatic
Somatosensory
sensation
association cortex
Gustatory cortex
(in insula)
Taste
Wernicke’s area
(outlined by dashes)
Primary visual
cortex
Visual
association
area
Auditory
association area
Primary
auditory cortex
Vision
Hearing
Motor association cortex
Primary sensory cortex
Primary motor cortex
Sensory association cortex
Multimodal association cortex
Figure 12.8a
Cerebral Sensory Activity
 Widely dispersed
 Parietal, temporal, and occipital lobes
 Concerned with conscious awareness of sensation
Primary Somatosensory Cortex
 In the postcentral gyri, parietal lobe
 Stimuli from skin, skeletal muscles, and joints
 Capable of spatial discrimination: identification of
body region being stimulated
Posterior
Sensory
Anterior
Sensory map in
postcentral gyrus
Genitals
Primary somatosensory cortex
(postcentral gyrus)
Copyright © 2010 Pearson Education, Inc.
Intraabdominal
Figure 12.9
Somatosensory Association Cortex
 Posterior to the primary somatosensory cortex
 Integrates sensory input from primary
somatosensory cortex
 Integrates and analyzes inputs such as: temperature,
size, texture, and relationship of parts of objects
being felt
 Keys in pocket
Visual Areas
 Primary Visual Cortex
 Occipital lobe
 Receives visual information from the retinas
 Visual Association Area
 Surrounds the primary visual cortex
 Uses past visual experiences to interpret visual stimuli (e.g.,
color, form, and movement)
 Complex processing involves entire posterior half of the
hemispheres
Auditory Areas
 Primary Auditory Cortex
 Temporal lobes
 Interprets information from inner ear (pitch, loudness, and
location)
 Auditory Association Area
 Located posterior to the primary auditory cortex
 Stores memories of sounds and permits perception of sounds
Cerebral Sensory Activity
Motor areas
Primary motor cortex
Premotor cortex
Frontal eye field
Central sulcus
Sensory areas and related
association areas
Broca’s area
(outlined by dashes)
Prefrontal cortex
Working memory
for spatial tasks
Executive area for
task management
Working memory for
object-recall tasks
Solving complex,
multitask problems
(a) Lateral view, left cerebral hemisphere
Primary somatosensory
cortex
Somatic
Somatosensory
sensation
association cortex
Gustatory cortex
(in insula)
Taste
Wernicke’s area
(outlined by dashes)
Primary visual
cortex
Visual
association
area
Auditory
association area
Primary
auditory cortex
Vision
Hearing
Motor association cortex
Primary sensory cortex
Primary motor cortex
Sensory association cortex
Multimodal association cortex
Figure 12.8a
Association Areas
 Receive inputs from multiple sensory areas
 Send outputs to multiple areas, including the
premotor cortex
 Allow us to give meaning to information received,
store it as memory, compare it to previous
experience, and decide on action to take
 Multimodal Association Areas
Multimodal Association Areas
 Three areas
 Prefrontal Cortex
 Posterior Association Area (not discussed here)
 Limbic Association Area
Cerebral Association Activity
Motor areas
Primary motor cortex
Premotor cortex
Frontal eye field
Central sulcus
Sensory areas and related
association areas
Broca’s area
(outlined by dashes)
Prefrontal cortex
Working memory
for spatial tasks
Executive area for
task management
Working memory for
object-recall tasks
Solving complex,
multitask problems
(a) Lateral view, left cerebral hemisphere
Primary somatosensory
cortex
Somatic
Somatosensory
sensation
association cortex
Gustatory cortex
(in insula)
Taste
Wernicke’s area
(outlined by dashes)
Primary visual
cortex
Visual
association
area
Auditory
association area
Primary
auditory cortex
Vision
Hearing
Motor association cortex
Primary sensory cortex
Primary motor cortex
Sensory association cortex
Multimodal association cortex
Figure 12.8a
Prefrontal Cortex
 Most complicated cortical region
 Involved with intellect, cognition, recall, and
personality
 Contains working memory needed for judgment,
reasoning, persistence, and conscience
 Development depends on feedback from social
environment
Limbic Association Area
 Part of the limbic system
 Provides emotional impact that helps establish
memories
 Connections with prefrontal cortex regulate
emotional expression
Cerebral Association Activity
Motor areas
Primary motor cortex
Premotor cortex
Frontal eye field
Central sulcus
Sensory areas and related
association areas
Broca’s area
(outlined by dashes)
Prefrontal cortex
Working memory
for spatial tasks
Executive area for
task management
Working memory for
object-recall tasks
Solving complex,
multitask problems
(a) Lateral view, left cerebral hemisphere
Primary somatosensory
cortex
Somatic
Somatosensory
sensation
association cortex
Gustatory cortex
(in insula)
Taste
Wernicke’s area
(outlined by dashes)
Primary visual
cortex
Visual
association
area
Auditory
association area
Primary
auditory cortex
Vision
Hearing
Motor association cortex
Primary sensory cortex
Primary motor cortex
Sensory association cortex
Multimodal association cortex
Figure 12.8a
Cerebral Lateralization
 Left hemisphere




Math
Logic
Language
Controls right side of body
 Right hemisphere





Visual-spatial skills
Intuition
Emotion
Art and music
Controls left side of body
Cerebral White Matter
 Projection tracts
 Connect cerebrum w/other body locations
 Association tracts
 Interconnect cerebral cortex (same side)
 Commissural tracts
 Connect two hemispheres
White Matter Tracts
Figure 12.10
Basal Nuclei
 An association of grey matter deep in cerebral
hemispheres
 Contribute to muscle coordination by excitatory
innervation
 Ex. Parkinson’s
Basal Nuclei
Questions?