Download The Brain [Fig 7.2 p. 98] • largest, most important part of the nervous

The Brain
“For I know the thoughts that I think toward you, says the LORD, thoughts of peace and not of evil,
to give you a future and a hope.” Jeremiah 29:11
[Fig 7.2 p. 98]
• largest, most important part of the nervous system
• 1) cerebrum: upper part of brain; coordinates thought, memory, and learned
behaviors
• 2) cerebellum: lower part of brain; helps control balance and coordinate voluntary
muscle activity
• 3) brain stem: part that connects spinal cord; controls involuntary activities and
activities of autonomic nervous system
• weighs about 3lb.
• Approximately 100 billion neurons each linked directly to about 100,000 others
forming more than 10 quadrillion connections
Cerebrum
• helps in areas of consciousness, memory, voluntary actions, thinking, intelligence
• right and left hemispheres split by longitudinal fissure
• [Fig 8.14 p.130]
• R hemisphere
L hemisphere
connected to L side of body
connected to R side of body
creativity
details
intuition
logic/known procedures
• corpus callosum: means of communication between hemispheres; mass of nerve fibers
located at the base of the cerebrum
• cerebral cortex – outer layer of cerebrum; gray matter made largely of cell bodies
which lack myelin, located largely in the cerebral cortex; cerebral cortex consists
mainly of nerve bodies located in a thin layer less than 3mm thick with axons
projecting to interior of cortex; cortex deeply grooved making it possible for
maximum amount of gray matter to fit in limited space
• white matter lies in interior and consists largely of myelin covered nerve fibers;
messages originating in cortex travel to other areas of brain; impulses from sense
organs travel along white nerve fibers to cerebral cortex
• lobes: regions that corresponds to major bones in the cranium; each body part
controlled by a specific location on a specific lobe; each hemisphere has its own lobe
• [Fig. 8.16 p. 132]
• 1) frontal – personality, judgement, self-control; motor area controls voluntary
movement of skeletal muscles
• 2) parietal – located behind frontal lobe; feel sensations such as temperature,
pressure, and pain; shape, texture
• 3) occipital – sense of vision
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4) temporal – hearing, taste, smell
cerebral palsy: damage to the cerebral motor area; intellect not affected
Cerebellum
• second largest brain region; located behind brain stem and just below occipital love
of cerebrum; tissue is organized as white and gray matter; smaller convolutions
• function – to coordinate skeletal muscle activity; cerebellum trained by cerebrum to
operate muscles habitually; most complex muscle coordination handled by the
cerebellum
Brain Stem
• located between cerebrum and spinal cord; all nerve fibers which connect the brain
and the spinal cord must pass through it
• medulla oblongata: lowest part of brain stem; nerve centers monitor and regulate
breathing, heartbeat, blood pressure, swallowing, sneezing; all major sensory and
motor pathways between body-cerebrum cross over here
• pons: “bridge”; links cerebrum and cerebellum; assists medulla oblongata in
regulating breathing; helps coordinate some eye movements and facial expressions
• midbrain: above pons; help coordinate movements of both eyes, adjusts size of pupils
in response to light, operates lens muscles to focus eyes on objects
• reticular formation: master switch of the cerebrum; controls consciousness; constantly
adjusts alertness level in response to senses and feedback from cerebral cortex;
damage causes coma
Limbic system
• brain structures clustered around brain stem at core of the brain, surrounded by
cerebrum; involved in coordinating different brain activities
• thalamus: routs activation from reticular formation/sensory impulses to cerebral cortex
• hypothalamus: control unit for body's autonomic systems; controls autonomic system
(through brain stem) and endocrine system (through pituitary gland); also responsible
for physical effects of emotions (hunger, thirst)
• hippocampus: processes factual memories for storage
• amygdala: helps generate emotions and process emotional memories
Mind and Brain Connection
• behaviorism: philosophy that behavior is determined by environment
• Christianity: man also has spiritual component which influences thought and behavior
Homework
Section 8.3 #1-4
Section 8.4 #1-4