The Nervous System:
Tissues and the Spinal Cord
Nervous & Endocrine Systems
Compare the
mode of
communication in
these two systems.
(Complete the
worksheet on
page 124 in your
course packet.
1
Organization of the Nervous System
In this flow chart, what do the components in blue have in common?
Explain why the Enteric Nervous System is referred to as
the “little brain”.
Where are the Autonomic sensory receptors located?
Basic Tasks of the Nervous System
Sensory Input:
Receptors monitor
both external and
internal
environments.
Integration: Process
the information (at
synapses) and often
integrate it with
stored information.
Motor output: If
necessary, signal
effector organs to
make an appropriate
response.
How is this similar to the normal function of
the endocrine system? How is it different?
Describe the receptor, control center, and
effector in several neural reflexes.
2
Basic Structure of a Reflex Arc
Review the lab exercise on reflexes that begins on p. 98 of
your packet, and the worksheet on p. 102.
Multipolar
neuron
Are dendrites always
shorter than axons?
Can the neuron
processes that
conduct information
toward the cell body
also be myelinated?
3
Structural Classification of Neurons
Compare the possible functions of these neuron types.
Give one location where these neurons would be found in the body.
Opportunity for practice…
What are the
classifications of
neurons according
to structure?
…according to
function?
Identify the parts of
a neuron in this
figure.
Give one possible
location for this
neuron cell body.
4
Neuroglia of the CNS
Which neuroglia have
a protective function?
Name the cell
type that provides
myelination in
the PNS.
Which neuroglia
provide myelination
in the CNS?
Which neuroglia are
involved in transport?
How are
oligodendrocytes
and Schwann
cells different?
Organization of Neuroglia in the CNS
What differences between
gray matter and white
matter are visible in this
figure?
From which embryonic
germ layer do these
neuroglia originate?
What is the blood-brain
barrier?
5
Gray and White Matter
For practice, label the parts of the brain and spinal cord
visible in these sections.
What structures are found predominately in gray matter?
…in white matter?
Why do you think white matter surrounds gray matter in the
spinal cord?
Review of Chemical Synapses
Compare with the structure and function
of an electrical synapse.
How does the action
differ between an
excitatory
neurotransmitter and an
inhibitory one?
6
Propagation of an Action
Potential
Why is the
resting
potential a
negative
number?
What is the significance of the
refractory period?
Refractory Period
Saltatory Conduction in Myelinated Axons
Action potentials jump from node to node without
depolarizing the region under the myelin sheath - called
saltatory conduction.
What cells myelinate fibers in the CNS?
In addition to the presence of a myelin
Fig. 48.11
sheath, what else may
increase the speed of
conduction along a neuron process?
7
Structure of Peripheral Nerves
Are nerves considered organs of the nervous system?
Why is there such a large c.t. component to nerves?
Regeneration of
Peripheral Nerve Fibers (1)
How might this injury
occur?
Is this a sensory neuron,
interneuron, or motor
neuron? (What function
would be lost?)
8
Regeneration of Fibers in the PNS (2)
What is this component of the nerve?
Regeneration of Fibers in the PNS (3)
What is a neuroma?
9
Review: Myelination in the CNS
How is myelination
different in the CNS from
the PNS?
Are oligodendrocytes
capable of reproduction?
Why is this significant?
Is there a neurolemmal
sheath around myelinated
fibers in the CNS? Why is
this significant?
Cranial and Spinal nerves of the PNS
Label the
nerves in these
figures.
Which nerves are classified as
sensory?…motor?…mixed?
10
Embryonic Origin of the
Central Nervous System
Use this figure to help interpret the flow
chart on page 176 in your course packet.
Structure and
Function of the
Spinal Cord
There are 31 segments to the
spinal cord; each segment giving
rise to a pair of ____________.
Name the two main
functions of the
spinal cord.
Why are there
cervical and lumbar
enlargements?
11