Worksheet VII: The Spinal
Cord
1. A bundle of nerve fibers in the CNS is called a(n):
____________________________.
2. Spinal cord tracts that conduct impulses up the cord to the brain
are _______________________ tracts.
3. Spinal cord tracts that carry impulses down from the brain are
__________________________ tracts.
4. Identify the protective covering, space, or structure associated
with the spinal cord based on the descriptions given below.
a. Bony protective covering of the spinal
cord.
____________________________
b. Space between wall of vertebral canal and dura
mater.___________________________
c. Space between dura mater and
arachnoid.
____________________________
d. Innermost meninx.
____________________________
e. Continuous with dura mater of
brain.
____________________________
f. Filled with blood vessels, fat, and
connective tissue. ____________________________
g. Injection site for anesthetics.
____________________________
h. Space between arachnoid and pia
mater.
____________________________
i. Lateral membranous extensions of pia
mater.
____________________________
j. Fixes position of spinal cord.
____________________________
k. Superior enlargement from 4th cervical to
1st thoracic.
Nerve supply to upper extremities arise
from.
____________________________
l. Spinal nerves that arise from lower cord
and exit
together.
____________________________
m. Region below lumbar enlargement where
spinal cord
tapers.
____________________________
n. Nonnervous fibrous tissue that attaches
spinal cord
to coccyx.
____________________________
o. Inferior enlargement running from 9th to
12th thoracics;
Supplies lower extremities.
____________________________
p. Arises from conus medullaris and is mostly
pia mater.___________________________
5. The spinal cord extends from the ________________________ of
the brain to between the
______________ and ____________ lumbar
vertebrae. ________ (Number) pairs of spinal nerves
exit the
spinal cord.
6. List the meninges and spaces surrounding the spinal cord from
outermost in innermost.
____________________________
____________________________
____________________________
____________________________
____________________________
____________________________
7. The spinal cord is divided into right and left sides by the
______________________ fissure and
the ______________________ sulcus.
8. Identify the regions or part of the spinal cross-section based on
the descriptions given below.
a. Middle portions of H; only found in thoracic,
upper lumbar, and sacral regions.
____________________________
b. Origin point for cell bodies of ANS.
____________________________
c. Gray area shaped like a butterfly or
H.
____________________________
d. Lower areas of gray matter; origin of cell
bodies for motor neurons.
____________________________
e. Cross bar of gray matter.
____________________________
f. Center opening in gray
commissure.
____________________________
g. Area housing CSF.
____________________________
h. Upper portions of gray matter.
____________________________
i. White substance surrounding gray
matter.
____________________________
j. Myelinated tracts next to median
sulcus.
____________________________
k. Myelinated tracts next to median
fissure.
____________________________
l. Myelinated tracts next to lateral gray
horns. ____________________________
m. Branch of spinal nerve housing sensory
fibers.____________________________
n. Branch of spinal nerve housing motor
fibers. ____________________________
o. Location of sensory neuron cell
bodies.
____________________________
p. 31 pairs of these structures.
____________________________
9. List 3 functions of the spinal cord.
__________________________________
__________________________________
__________________________________
10. Identify the spinal cord tracts listed below as ascending or
descending.
a. Anterior spinothalamic tract.
____________________________
b. Pyramidal tracts.
____________________________
c. Lateral corticospinal.
____________________________
d. Anterior corticospinal.
____________________________
e. Rubrospinal.
____________________________
f. Lateral spinothalamic tract.
____________________________
g. Fasciculus gracilis and cuneatus.
____________________________
h. Posterior spinocerebellar.
____________________________
i. Anterior spinocerebellar.
____________________________
11. Identify the specific name of the spinal cord tracts based on the
descriptions given below.
a. 2 pt discrimination; conscious
proprioception;
stereognosis; wt discrimination;
vibration.
____________________________
b. Conveys sensations of pain and temperature
to the
thalamus.
____________________________
c. Conveys sensations of touch and pressure to
the
thalamus.
____________________________
d. Coordinates precise, discrete
movements.
____________________________
e. Coordinates movements of axial
skeleton.
____________________________
f. Coordinates precise movements; originates
from
red nucleus.
____________________________
g. Subconscious proprioception from one
side. ____________________________
h. Subconscious proprioception from both
sides. ____________________________
i. Cell bodies in spinal cord; axons terminate in
thalamus;
tract in lateral column.
____________________________
j. Cell bodies in spinal cord; axons terminate in
cerebellum;
tract in anterior column.
____________________________
12. _____________________ tracts are myelinated neurons that
descend from the cerebral cortex to somatic
motor neurons without
synapsing along the way.
13. A _________________ center integrates actions between sensory and
motor neurons.
14. A ___________________pathway is the path a nerve impulse
follows from its origin in dendrites to its
termination elsewhere. One
kind of conduction pathway is the ___________________.
15. A ___________________ is 2 or more neurons that conduct a
nerve impulse from a receptor to the brain
or spinal cord using sensory
neurons and then to an effector by way of motor neurons.
16. Name the 5 basic components of a reflex arc in the correct sequence
from origination to termination.
_____________________________
_____________________________
_____________________________
_____________________________
_____________________________
17. List 2 examples of effector structures.
_____________________________
_____________________________
18. Automatic, stereotypic, reactions to stimuli are
called:
_____________________________
19. The __a__ reflex is __b__; that is, it has a sensory neuron
that synapses directly with a motor neuron.
This reflex is initiated by
a receptor called the __c__. The nerve impulse is conducted to
the spinal cord by
a __d__ neuron. This __d__ neuron forms 3 axon
collaterals. Axon collateral number 1 synapses directly
with a
__e__ neuron that exits the spinal cord through the __f__ and
goes to the muscle being stretched. The
muscle being stretched is __g__
(stimulated/inhibited) and therefore __h__ (relaxes/contracts).
This action
prevents the muscle from being __i__ (overstretched/
contracted too forcefully). Axon collateral number 2
synapses with an __j__. This __j__ is stimulated and causes __k__
(stimulation/inhibition) of the motor
neuron going out to the
antagonist. The antagonist is allowed/caused to __l__
(relax/contract). Axon collateral
number 3 synapses with an __j__
using an ascending tract to the __m__.
a. ___________________________
g.
___________________________
b. ___________________________
h.
___________________________
c. ___________________________
i.
____________________________
d. ___________________________
j.
____________________________
e. ___________________________
k.
____________________________
f. ____________________________
l.
____________________________
m.
___________________________
20. A reflex that involves only one side of the body is said to be:
___________________________.
21. _____________________________ is when the agonist muscle is
stimulated to contract while the antagonist
is inhibited.
22. Name 2 important pieces of information gained by the doctor from
the knee-jerk reflex.
_____________________________
_____________________________
23. The __a__ reflex is __b__; that is, it has a sensory neuron
that synapses with an interneuron. This
reflex is initiated by a
receptor found in the tendons called the __c__. The nerve impulse
is conducted to
the spinal cord by a(n) __d__ neuron. This __d__
neuron forms 3 axon collaterals. Axon collateral number
1
synapses with a (n) __e__ neuron. This __e__ neuron synapses with a
__f__ neuron that exits the spinal
cord through the __g__ and
goes to the muscle building tension. The muscle building tension
is __h__
(stimulated/inhibited) and therefore __i__
(relaxes/contracts). This action prevents the muscle from being
__j__
(overstretched/ contracted too forcefully).
Axon collateral number 2 synapses with a(n) __k__. This
__k__ is
stimulated and causes __l__ (stimulation/inhibition) of the
motor neuron going out to the antagonist. The antagonist
is
allowed/caused to __m__ (relax/contract). Axon collateral number
3 synapses with an __k__ using an ascending
tract to the __n__.
a. ___________________________
h.
___________________________
b. ___________________________
i.
___________________________
c. ___________________________
j.
____________________________
d. ___________________________
k.
____________________________
e. ___________________________
l.
____________________________
f. ____________________________
m.
___________________________
g. ____________________________
n.
___________________________
24. The ________________________ reflex is a response to a
harmful stimulus. It involves another reflex that is
contralateral. This reflex helps stimulate muscles on the
opposite side of the body that maintain ___________________.
25. What is meant by reciprocal innervation and why is this phenomenon
important? _____________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
26. What is a monosynaptic reflex and how is this type of synapse an
advantage over a multisynaptic one?
________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
27. Draw and label a cross-section of the spinal cord including two
spinal nerves. ______________
28. Draw a schematic of a stretch reflex using a spinal cord
cross-section. (You do not need to label spinal cord
structure, but do
need to identify types of neurons and effectors.) _________________
29. Why, during a withdrawal reflex, is it important to pair it with
the cross-extensor reflex? _____
_____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
30. Answer these questions about the lateral spinothalamic tract:
1) Where is it located? 2) Is it ascending or descending?
3) What symptoms would result if this tract was damaged? ___________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
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Exam 4