The Nervous System
Overview
Two major divisions: _____nervous
system and _____ nervous system
 CNS – _____ and spinal cord; located in
_____ cavity
 Spinal cord – conducts sensory info
from the _____NS to the _____;
conducts motor info from the brain to
effectors (muscles and glands); r_____
center
 Neurons (4:43)

Overview
Brain – receives input from the _____
_____ as well as from its own nerves;
central processing center
 White matter – bundles of axons covered
with _____ (myelin gives it ________
appearance); found in brain and cord
 Gray matter – masses of dendrites and cell
bodies; not covered with _____ so it
appears _______
 Three meninges – _____, _____, and
_____ maters; CSF in between arachnoid
and pia

Blood-Brain Barrier
Tight _____ junctions between endothelial
cells of brain capillaries
 Maintains brain _____. The brain must be
kept isolated from any changes in the _____,
particularly after meals or exercise.
 Allows essential molecules, such as oxygen
and glucose, to pass from the _____ to the
CNS but blocks more massive molecules like
hormones and neurotransmitters

Blood-Brain Barrier
 Also
prevents most _____ from infiltrating
the CNS
 _____ cells such as lymphocytes,
monocytes and neutrophils cannot
penetrate this barrier.
 Prevents full-blown _____ response in the
CNS (bad for delicate neural tissue)
 Creates challenge for biochemists as they
develop medicines Why?
BBB
BBB animation (1:58)
Challenges of the BBB
(4:53)
Cerebrospinal Fluid
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Produced in masses of special _____ called choroid
plexuses
Three primary functions:
 Buoyancy for the brain, c_____, chemical stability
Located between the _____ and _____ maters
Flows uninterrupted through the CNS through the
cerebrospinal canal of the spinal cord to the _____ in
the _____ then exits CNS through veins draining the
brain
Constant _____ must be maintained
The total volume of CSF in an adult is about _____ ml.
CSF is produced at a rate of 600-700 ml per day
The Brainstem

Three parts: medulla oblongata, pons, and
midbrain
 Medulla controls _____ functions like breathing,
heartbeat, and blood _____; reflex center
 Pons is the relay station between the _____
and the rest of the CNS; may play a role in
_____; works with medulla to regulate _____
rate
 Why do we dream? (6:30)
 Midbrain acts as a relay station between _____
and spinal cord or cerebellum; also controls
sensory processes
The Brain

Cerebellum – “little brain”; c_____,
equilibrium and b_____; muscle tone; only
10% of brain but contains more _____ than
the rest of the brain combined; _____
working part of the brain; capable of
making _____based on previous
experiences; enables rest of brain to work
more _____ because it can carry out tasks
_____ without conscious thought (speech)
The Brain

Cerebrum – “brain”; only
part of the brain involved
in consciousness; largest
part; divided into two
_____; superficial layer
called the _____; cortex
is highly folded
(increases _____
_____); neocortex
(higher intelligence –
found only in m_____);
contains four distinct
areas called _____
The Brain
Hypothalamus – maintains ____; center
for _____, thirst, emotions, body _____,
circadian rhythms; connected to
autonomic NS; controls the _____ gland
(endocrine system)
 Thalamus – sensory and _____
functions; last relay site before info
reaches the _____; organizes info and
sends it to appropriate areas of the
_____

Human Biological Clock
(Circadian Rhythms)
Sleep Patterns
(Monitored by Josie Harrington’s phone while she slept)
The Brain
Cerebrum
Corpus Callosum
Thalamus
Hypothalamus
Cerebellum
Medulla Oblongata
Spinal Cord
Pituitary
The Brain
system – includes portions of
the thalamus, hypothalamus, and
cerebrum
 Limbic
 Amygdala – memory, emotions, fear
 Hippocampus – memory and learning;
converts _____-_____ memories into
_____-_____; associates sensory
experiences (like smells) to _____;
spatial relationships
Limbic System
Man with no memory (3:05)
World memory champion - Part 1 (4:58)
World memory champion - Part 2 (5:34)
The Spinal Cord
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Extension of the _____
Ends between L1 and L2
Conducts impulses
between periphery and
_____
Central canal (extension
of brain ventricles) that
contains _____
Covered by the three
_____
Ascending and
descending nerve tracts
Peripheral Nervous System (PNS)
Somatic NS – controls _____
movement; acetylcholine is primary
_____; includes all the neurons
connected with _____ muscles, skin,
and sense organs
 Autonomic NS – controls _____
movement; unconscious processes;
maintains _____; 2 divisions: _____ and
_____

Autonomic NS


Sympathetic division –
“_____-or-_____”
response; energy
generation; inhibits
digestion; diverts blood
from _____ system and
skin to _____ tissue and
_____; dilates breathing
passages; increases
_____ _____; dilates
_____ (increased light);
norepinephrine, aka,
adrenaline
Fight-or-Flight (4:30)
Autonomic NS

Parasympathetic
division – “_____
and _____”;
increases blood flow
to _____ system;
promotes digestion
and absorption;
constricts _____
_____; slows _____
_____; acetylcholine
Neuroglial Cells (Neuroglia)

Schwann cells – named after Theodor _____; only
in peripheral NS; form the insulative _____ _____
around axons (like the covering around electrical
wires); enable quick _____ of electrical _____
within an _____
Neuroglial Cells (Neuroglia)
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Nodes of Ranvier – gaps between Schwann cells
that increase the conduction of an _____ down an
_____; allow impulse to “_____” down the axon
Because the axonal membrane is exposed at the
node, nutrients and wastes are able to enter and
exit the _____.
Neuroglial Cells (Neuroglia)

Microglial cells – _____-_____crew;
phagocytic; activated after _____ or disease
and remove damaged cells or kill invading
_____; derived from blood _____ _____
Microglial cell (green)
and astrocyte (red) after
injury to a blood
capillary. The microglial
cell extensions
surround the injured
area.
Neuroglial Cells (Neuroglia)
Astrocytes – connect neurons with
_____, which means?
 Integral part of the _____-_____ barrier
 Most abundant cell in the brain

Neuroglial Cells (Neuroglia)
Oligodendrocytes – like Schwann cells,
form the _____ _____ around axons
 Only in the CNS

Oligodendrocyte supplying myelin for
many axons
Neuroglial Cells (Neuroglia)

Ependymocytes – line cavities (_____)
within the CNS; assist in production and
circulation of _____ with the help of hairlike cellular extensions called _____
Glial cell review
(8:00)
The Synapse
Vesicles (purple
spheres) are filled
with _____. At the
synapse, the vesicles
fuse with the neuron’s
cell _____ and
release their _____,
which are then picked
up by receptors on the
receiving neuron’s cell
_____.