The Nervous System - Lab Exercise 5

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The Nervous System- Lab Exercise 5
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Divisions of the Nervous System

• Central nervous system (CNS) brain spinal
  cord
• Peripheral nervous system (PNS) cranial nerves
  spinal nerves

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The Central Nervous System
CNS well protected by bones (cranial
vertebrae), CT meninges, cerebrospinal fluid
(CSF)
Meninges Connective tissues that surround and
protect the brain and spinal cord (CNS)

• 3 layers
• Dura Mater
• Arachnoid
• Pia Mater

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Meninges
Dura Mater tough, fibrous outer layer

• 2 layers thick around brain with creation of
  dural sinuses between layers

• 1 layer around spinal cord with epidural space
  external

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Meninges
Arachnoid spidery web-like middle layer
Pia Mater delicate, thin inner layer adhered
to brain cord extension of pia mater (filum
terminale) extends from tip of cord to coccyx to
anchor cord in place
Subarachnoid space between arachnoid pia
mater contains cerebral spinal fluid (CSF)
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Superior sagittal sinus
Dura mater (gray color)
Arachnoid (orange color)
Subarachnoid space (blue color)
Pia mater (red color)
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The Brain

• Brain stem
• medulla oblongata (M.O.)
• pons
• midbrain
• Diencephalon
• thalamus
• hypothalamus
• mamillary bodies
• epithalamus (pineal gland)
• Cerebrum
• Cerebellum

Cerebrum
T
P
P
H
midbrain
M
Cerebellum
pons
m.o.
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Cerebrum
T
P
H
midbrain
M
pons
Cerebellum
m.o
Spinal cord
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The Brainstem

• medulla oblongata (M.O.)
• pons
• midbrain
• cerebral peduncle
• cerebral aqueduct of midbrain
• corpora quadrigemina
• superior colliculi
• inferior colliculi

pons
Cerebral peduncle
m.o.
Cerebral aqueduct of midbrain
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Cerebral aqueduct of midbrain
Superior colliculus
Inferior colliculus
Cerebral peduncle
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The Diencephalon

• thalamus
• intermediate mass
• hypothalamus
• mamillary bodies
• connects to pituitary gland via infundibulum
• epithalamus (pineal gland)

M
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Cerebrum
convolutions
gyrus
sulcus
4 lobes per hemisphere- frontal, parietal,
temporal, occipital
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The Cerebrum
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The Cerebellum

• gray matter folia
• white matter arbor vitae
• separated from cerebrum by transverse fissure

Transverse fissure
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Cerebrospinal Fluid (CSF)

• clear, colorless fluid formed by filtration of
  blood plasma by choroid plexuses within
  ventricles of the brain.

• functions in protection of CNS, support,
  nutrient supply, waste removal

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CSF Circulation
Lateral ventricles (in cerebral hemispheres) ?
interventricular foramen ? third ventricle (in
diencephalon around thalamus) ? cerebral aqueduct
of midbrain ? fourth ventricle (between
pons/cerebellum) ? subarachnoid space central
canal of SC
Lateral ventricle (behind septum pellucidum)
Third ventricle
Aqueduct of midbrain
Fourth ventricle
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Reabsorption of CSF through arachnoid
granulations (arachnoid villi) of dural sinuses
(superior sagittal sinus) ? into cerebral veins
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Superior sagittal sinus
Arachnoid granulation (villus)
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Cranial Nerves

• 12 pairs of nerves that connect to the brain
  provide motor, sensory /or autonomic
  (parasympathetic) function

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I (olfactory bulb)
Olfactory tract
Optic chiasm
Optic tract
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III
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VII
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VIII
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