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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); _____
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 (like _____ 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.

 Why is this a concern?
Prevents full-blown _____ response in the
CNS (bad for delicate neural tissue)
 Creates challenges for scientists as they
develop CNS _____ and chemotherapies.
Why?
 Many of these meds require intrathecal
administration, rather than vascular injection
or taking a pill

BBB
BBB animation (1:58)
Challenges of the BBB
(4:53)
BBB crossed for the first
time! (3:25)
Computer-generated Image of
the BBB
Cerebrospinal Fluid
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Produced in masses of special _____ called choroid
plexuses; 99% H2O
Five primary functions:
 Buoyancy for the brain, c_____, chemical stability,
f_____ system, clears out _____ (esp. when we sleep)
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 _____, which is
highly folded (increases
_____ _____); neocortex
(higher intelligence –
found only in _____);
contains four distinct
areas called _____
The Brain
Hypothalamus – maintains ____; center
for _____, thirst, emotions, body _____,
_____ 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


Extension of the _____
Ends between L1 and L2
 Spinal taps ALWAYS done
below _____

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Conducts impulses
between periphery and
_____
Central canal (extension
of brain ventricles) that
contains _____
Covered by the three
_____
Ascending and
descending nerve tracts
Reflexes and the Reflex Arc
Reflexes are r____,
p____, and in____
responses to stimuli.
 Involve as few
synapses as
possible – Why?
 What organ is
missing from a
typical reflex arc?
 Why do we feel pain
after we’ve reacted?

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 (6:35)
Autonomic NS

Parasympathetic
division – “_____
and _____”;
increases blood flow
to _____ system;
promotes digestion
and absorption;
constricts _____
_____; slows _____
_____; acetylcholine
Intro to Neuroglia (Glia)
Neuroglia literally means “_____ _____”.
 They’re the supporting cast for the neurons
 Their four main functions are:
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To surround neurons and _____ them in place
To supply _____ and O2 to neurons
To _____ one neuron from another
To destroy _____ and remove _____ neurons
Each type has its own specialized _____ &
_____
 Because glial cells _____ and neurons
generally don’t, most brain _____ are gliomas.
 There are two in the PNS and four in the CNS.

PNS Neuroglia (Glia)

Schwann cells – named after Theodor _____; form
the insulative _____ _____ around axons (like the
covering around electrical wires); enable quick _____
of electrical _____ within an _____; outer layer called
the _____ (protective & regenerative layer of Schwann)
PNS Neuroglia (Glia)


Satellite cells – _____, cushioning cells; appear to be
involved in the regulation of _____; connect neurons
with blood _____, which means?
It appears that they’re _____ cells that carry out a wide
variety of _____; still much to be _____ about them
CNS Neuroglia (Glia)

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 capillary. The
microglial cell
extensions surround the
injured area – Why?
What’s it doing?
CNS Neuroglia (Glia)


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Astrocytes – they’re the CNS equivalent to
satellite cells in the PNS, which means . . .
Integral part of the _____-_____ barrier
Most abundant cell in the brain
CNS Neuroglia (Glia)

Ependymocytes – line cavities (_____)
within the CNS; assist in production and
circulation of _____ with the help of hairlike cellular extensions called _____
CNS Neuroglia (Glia)

Oligodendrocytes – like Schwann cells,
form the _____ _____ around axons
 As many as 50 axons! (Schwann cells: only one)
Glial cell review (8:00)
Oligodendrocyte supplying myelin for
numerous axons
Nodes of Ranvier


Nodes of Ranvier – gaps between Schwann cells (PNS)
and oligodendrocytes (CNS) that increase the
conduction of an _____ down an _____; allow impulse to
“_____” down the axon (saltatory conduction)
Because the axonal membrane is exposed at the node,
nutrients and wastes are able to enter and exit the
_____.
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 _____.