Section 4 Notes over CNS

1. D E F O R D
THE NERVOUS SYSTEM

2. CENTRAL NERVOUS SYSTEM
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3. DIVISIONS OF THE BRAIN
• Hindbrain
• Functions are essential to
maintaining life
• Midbrain
• Connects hindbrain to
forebrain
• Forebrain
• Higher functioning (thinking,
decisions, dreaming)
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4. MAJOR BRAIN REGIONS
1. Cerebrum
2. Diencephalon
3. Brain Stem
4. Cerebellum
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3
4
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5. CEREBRUM
• The largest and most superior part of the brain is
the cerebrum
• Responsible for voluntary muscle movements,
personality, interpreting sensory information, and
problem solving
• Surface of cerebrum shows elevated ridges of
tissue called gyri, shallow grooves called sulci,
and deep grooves called fissures
• Cerebrum is divided by the longitudinal fissure
into right/left halves called hemispheres 5

6. 6
In most individuals, one hemisphere is dominant over the other.
Are you right brain or left brain dominant? Click HERE to find out!
The left
brain
controls the
right half of
the body.
The right
brain
controls the
left half of
the body.

7. CEREBRUM
CEREBRAL CORTEX
• Outermost layer of the
cerebrum
• Composed of gray matter
• Responsible for thinking
and processing
information from the five
senses
Gray matter contains the
tightly packed cell bodies
of neurons.
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8. CEREBRUM
CEREBRAL LOBES
• Fissures divide the cerebral cortex
into four sections called lobes
• Lobes are named for the cranial
bones that cover them
• Frontal (pink)
• Parietal (yellow)
• Temporal (green)
• Occipital (purple) 8

9. CEREBRUM
FRONTAL LOBE
• Motor function
• Problem solving
• Emotional traits
• Speaking
• Judgment
PARIETAL LOBE
• Processes
sensory
information such
as touch,
temperature, and
taste
• Reading
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10. CEREBRUM
TEMPORAL LOBE
• Auditory perception (hearing)
• Olfactory area is deep inside (smell)
• Language input
• Behavior
• Memory
OCCIPITAL LOBE
• Visual processing
center
• Color perception
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11. CEREBRUM
CORPUS CALLOSUM
• Large fiber tract that
connects the two
cerebral hemispheres
• Allows communication
between the 2 sides of
the cerebral cortex
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12. DIENCEPHALON
• Superior to the
brainstem, enclosed by
cerebrum
• 3 major structures:
• Hypothalamus
• Thalamus
• Epithalamus
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13. DIENCEPHALON
HYPOTHALAMUS
• Important in maintaining
homeostasis: maintains body
temperature, water balance,
and metabolism
• Part of the limbic system which
controls emotions and drives
such as hunger & thirst
• Controls the pituitary gland
hypothalamus
pituitary gland
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14. DIENCEPHALON
THALAMUS
• Relay station for sensory impulses
traveling to the sensory cortex
EPITHALAMUS
• Contains the pineal gland and choroid
plexus, which forms the cerebrospinal
fluid
• Pineal gland also produces melatonin,
which helps to modulate sleep patterns
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15. BRAIN STEM
• Midbrain – reflex center for vision
and hearing, eye movements
• Pons – coordinates information
between brain areas, involved in
breathing
• Medulla Oblongata – blood
pressure, breathing, heart rate,
swallowing, sneezing, coughing,
and vomiting
pons
medulla
oblongata
midbrain
The medulla oblongata merges
into the spinal cord.
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16. CEREBELLUM
• Second largest part of the
brain
• Precise timing for skeletal
muscle activity
• Balance and equilibrium
• Makes body movements
smooth & coordinated
The cerebellum is inferior to the
occipital and temporal lobes. It
has two hemispheres that are
covered with parallel grooves.
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17. PROTECTIVE STRUCTURES
• Bones: skull and vertebrae
• Meninges: connective tissue
membranes; covers brain
and spinal cord
• Cerebrospinal Fluid (CSF)
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18. THREE MENINGES
• Dura mater: tough, outer,
double-layered membrane
• Arachnoid mater: web-like
middle layer
• Pia mater: innermost membrane
that clings tightly to the surface
of the brain and spinal cord
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19. CEREBROSPINAL FLUID
• Continually formed from plasma
by clusters of capillaries in
cavities called ventricles
• Provides a watery cushion for
the brain and spinal cord
• Significant changes in CSF
composition may indicate
problems
CSF is obtained for testing
through a procedure called a
spinal or lumbar tap.
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20. BLOOD-BRAIN BARRIER
• The brain depends on a very stable
internal environment; the blood-brain
barrier maintains a constant environment
for the brain
• The BBB protects the brain from
• "foreign substances" in the blood that
may injure the brain
• from hormones and neurotransmitters in
the rest of the body
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21. SPINAL CORD
• Continuous with the brain
stem; connects the brain to
nerves
• Enclosed within vertebrae;
extends from the foramen
magnum to L1 or L2
• Provides a 2-way path to and
from the brain
• Major reflex center
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22. SPINAL CORD
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• Afferent sensory
information enters
via the dorsal root
• Efferent signals
exit to muscles
and glands via the
ventral root