Download SI Wednesday November 5, 2008

SI Wednesday November 4, 2009
Spinal Cord / Spinal Nerves
Identify the following regions on the image below
Spinal Nerve
Ventral Roots
Dorsal Roots
Dorsal Root Ganglia
Anterior Median Fissure
Posterior Median Sulcus
Dorsal Horns
Dorsal Columns
Ventral Horns
Ventral Columns
Lateral Horns
Lateral Columns
2 Locations of Somatic Sensory Neurons
Location of Visceral Motor Neurons
Location of Visceral Sensory Neurons
Location of Somatic Motor Neurons
Briefly Answer the Following:
How is it possible that there is a C8 Spinal Nerve if there are only 7 Cervical Vertebrae?!
There are 31 pairs of spinal nerves…how are they broken down based on the region in the vertebral column where
they exit the vertebral cavity?
Why are the pockets of gray matter corresponding to the Sacral Segments of the spinal cord not actually situated at
the level of the sacrum?
Where does the spinal cord end and how is it anchored to the sacrum/coccyx?
What are gray matter enlargements and why do they occur?
1
SI Wednesday November 4, 2009
Spinal Cord / Spinal Nerves
Multiple Choice Exercise
1. Dorsal Root Ganglion neurons are derived from:
A. The Caudal portion of the neural tube
B. The Rostral portion of the neural tube
C. Neural Crest Cells
D. Somites
2. In adults, the conus medullaris corresponds approximately to:
A. L1
B. The coccyx
C. The base of the myelencephalon
D. Cessation of spinal cord elongation immediately after birth
3. In adults, the filum terminale runs from:
A. The coccyx to the foramen magnum
B. L1 to the coccyx
C. L1 to the foramen magnum
D. The cervical plexus to the lumbar plexus
4. The S5 spinal segment in an adult corresponds approximately to which region along the vertebral column?
A. Lumbar Vertebrae #1
B. Inferiorly in the Sacral Cavity
C. Superiorly in the Sacral Cavity
D. Thoracic Vertebrae #5
5. Upon exiting the spinal cord, spinal nerves may fuse together to form:
A. Ganglia
B. Plexuses
C. Fascicles
D. Cauda Equina
6. The region of skin innervated by 1 pair of dorsal roots is referred to as:
A. Motor Units
B. Somites
C. Dermatomes
D. Peripheral Nerve Fields
7. It is safe to perform a spinal tap in the cauda equina because:
A. There are no oligodendrocytes in this region
B. There is no cerebrospinal fluid in this region
C. There are no ventral or dorsal roots in this region
D. There are no nerve cell bodies in this region
8. In order for the left frontal cortex to govern motor activity in the right leg (through synapsing on alpha motor
neurons in the ventral horn), axon tracts must ______ somewhere along the way.
A. Commisurate
B. Associate
C. Become Ensheathed
D. Decussate
E. Branch to axon collaterals and telodendria
9. Spinal cord gray matter can contain all of the following except:
A. Dendrites
B. Interneurons
C. Satellite cells
D. The neurotransmitter glutamate
2
SI Wednesday November 4, 2009
Spinal Cord / Spinal Nerves
10. Which statement is true with regard to dorsal root ganglia?
A. They are a feature of the basal ganglia
B. They receive information only from the posterior portion of the body
C. They contain pseudo-unipolar neurons
D. They are within the central nervous system
11. Dorsal and Ventral Roots fuse to form _______ which exit the vertebral column at _______.
A. Cauda Equina; the space between the pedicles of two vertebrae
B. Spinal Nerves; Intervertebral Foramen
C. Plexuses; Vertebral Foramen
D. Ramii; the space between the pedicles of two vertebrae
12. The spinal nerves within the vertebral cavity below the level of the conus medullaris are collectively referred to
as:
A. Filum Terminale
B. Spinal Meninges
C. Cauda Equina
D. The Lumbar Enlargement
13. If you looked at a transverse section of the following regions along the spinal cord, in which would you expect to
see the greatest amount of white matter?
A. C2
B. T5
C. L1
D. S5
14. Cell Bodies of Somatic Moter Neurons are located in the:
A. Dorsal Root Ganglia
B. Lateral Gray Horn
C. Ventral Gray Horn
D. Lateral White Columns
15. Your ability to breathe would be greatly diminished if the following structure is damaged:
A. The Brachial Plexus
B. The Lumbar Plexus
C. Cranial Nerve # 12
D. The Phrenic Nerve
16. Where does Spinal Nerve C6 exit the vertebral column?
A. Through the intervertebral foramen formed by C5 and C6
B. Through the intervertebral foramen formed by C6 and C7
C. Through the intervertebral foramen formed by C7 and T1
D. Through the intervertebral foramen formed by T6 and T7
17. Which is true about nerve fascicles?
A. They are encased in perineurium
B. They contain only one type of axon (somatic sensory, somatic motor, visceral sensory, or visceral
motor)
C. The are encased in Epimysium
D. The are ensheathed by Schwann cells
18. Why is there greater ratio of gray matter to white matter at the C5 segment of the spinal cord than there is at the
T5 segment?
A. Because generally the ratio of gray matter to white matter decreases as you move down the spinal cord.
B. Because there are more motor units for the muscles of the upper extremity than there are for the muscles
of the upper chest and trunk
C. Because generally the ratio of gray matter to white matter increases as you move down the spinal cord.
D. Because all of the visceral motor neurons innervating the vital organs are located at the level of C5
3