Week 3: Spinal Cord/Spinal Nerves Flashcards
The gracile, cuneate fasciculi and spinothalamic tract are all:
a. Descending tracts
b. Crossed
c. Uncrossed
d. Ascending tracts
d. Ascending tracts
True/false: the spinal cord is shorter than the spinal canal.
TRUE
the spinal cord is shorter than the spinal canal.
What does the Bell-Magendie law state?
Afferent sensory fibers enter the spinal cord through the dorsal roots of spinal nerves; motor and efferent fibers leave by way of the ventral roots
List the four structures/components protecting the spinal cord.
- The vertebrae
- Attaching ligaments
- The meninges and
- Cerebrospinal fluid , CSF (cushioning effect)
What is the Denticulate Ligament made out of?
pia–arachnoid
tissue (also called PACHYMENINGES)
The cuneate fasciculi, vestibulospinal tract and gracile are all:
a. Descending tracts
b. Crossed
c. Uncrossed
d. Ascending tracts
c. Uncrossed
This is the space that exists
between the dura mater and
the wall of the spinal canal.
a. Subarachnoid space
b. Epidural space
c. Denticulate Ligament
e. CSF
b. Epidural space
• It is filled with fatty tissue
some protection
• It contains a venous plexus.
What is the innermost meningeal layer?
Pia mater
The spinal cord has ___
external segments which are
demonstrated by the presence of ___ pairs of spinal nerves.
31, 31
The spinal cord ends at the _______, which tapers abruptly into a slender filament called the_____.
a. cervical enlargement, e lumbosacral enlargement
b. dorsal forniculus, dorsolateral fasciculus
c. conus medullaris, filum
terminale
d. cauda equina, coccygeal nerve
c. conus medullaris, filum
terminale.
The nerve supply of the upper limbs comes from:
a. thoracic spinal nerves
b. lumbosacral plexuses
c. cauda equina
d. brachial plexuses
d. brachial plexuses
The surface of the spinal cord is marked by two longitudinal furrows. What are they?
The deep ventral (anterior) median fissure The dorsal (posterior) median sulcus (a shallow midline furrow).
The lateral horn of spinal grey matter exists only in:
a. the thoracic and upper lumbar segments
b. the cervical enlargement
c. the lumbosacral roots
d. the sacral and mid-sacral segments
a. the thoracic and upper lumbar segments
List the three funiculi or “columns” of the spinal cord white matter.
– The dorsal funiculus
– The lateral funiculus
– The ventral funiculus
Which of the following is NOT true regarding the lateral corticospinal tract?
a. It is a descending tract
b. It decussates
c. It consists of axons of neurons in the cortex of the frontal and parietal lobes
d. It is in the ventrolateral fasciculus
e. fibers destined for the lowest levels of the spinal cord are the most laterally placed.
d. It is in the ventrolateral fasciculus
Correction: It is in the Dorsolateral Fasciculus
Two regional enlargements exist in the spinal cord. What are they?
The Cervical enlargement includes segments
C4 to T1
The Lumbosacral enlargement includes the
segments L2 to S3
The fasciculus gracilis and fasciculus cuneatus comprise the:
A. Dorsal Forniculus
B. Lateral Foniculus
C. Ventral Foniculus
A. Dorsal Forniculus
What suspends the spinal cord in the dural sheath?
Denticulate Ligament
The nerve supply of the lower limbs comes from:
a. thoracic spinal nerves
b. lumbosacral plexuses
c. cauda equina
d. brachial plexuses
b. lumbosacral plexuses
True/False: the dorsal funiculus consists of a large body of ascending axons.
TRUE
the dorsal funiculus consists of a large body of ascending axons.
The lateral corticospinal tract, reticulospinal tract, unmyelinated hypothalamospinal fibers and the dorsal spinocerebellar tract form the ______?
a. Ventrolateral Fasciculus
b. Dorsal Funiculus
c. Dorsolateral Fasciculus
d. Ventral Funiculus
c. Dorsolateral Fasciculus
What is the function of the dorsal funiculus?
Adapted for the purpose of discriminative qualities of
sensation
– including the ability to recognize changes in the positions of tactile
stimuli applied to the skin and
– conscious awareness of movement and of the positions of joints.
Which pathway is concerned mainly with skilled volitional movements?
a. Spinothalamic tract
b. Reticulospinal tract
c. Ventral spinocerebellar tract
d. Dorsal spinocerebellar tract
e. Lateral corticospinal tract
e. Lateral corticospinal tract
Which tract arises from the paraventricular nucleus of the hypothalamus and ends among the preganglionic autonomic neurons in segments T1 to L3 and S2 to S4?
a. Reticulospinal tract
b. The spinoreticular tract
c. Unmyelinated hypothalamospinal fibers
d. Lateral corticospinal tract
e. Ventral spinocerebellar tract
f. The spinotectal tract (or spinomesencephalic tract)
Unmyelinated hypothalamospinal fibers
Some hypothalamospinal axons contain the peptide oxytocin necessary for uterine contraction during birth, and
myoepithelial cells contraction during milk-let-down reflex
What is the function of the dorsal spinocerebellar tract?
This tract conveys proprioceptive information
from proprioceptors in the skeletal muscles and
joints to the cerebellum
Corticospinal fibers (in the Lateral corticospinal tract) from the frontal cortex terminate mainly in the ______
a. dorsal horn
b. intermediate gray matter and the ventral horn
c. Muscle spindles
d. Nucleus of Onuf
b. intermediate gray matter and the ventral horn
What is the function of the Reticulospinal tract (Raphespinal tract)?
The raphespinal tract modifies the transmission from the dorsal horn of impulses initiated by noxious stimuli, which produce painful sensations.
The spinothalamic tract in the Ventrolateral Fasciculus is:
a. ascending
b. descending
c. Crossed (contralateral)
d. Uncrossed (ipsilateral)
a. ascending
c. Crossed (contralateral)
Where does the ventral spinocerebellar tract begin and end?
It arises from the base of the dorsal horn and from the spinal border cells of the ventral horn of the
lumbosacral segments.
Ends in the cerebellar cortex
True/false: Ventral Funiculus tracts are descending.
TRUE: Ventral funiculus tracts are descending.
Which Ventrolateral Fasciculus component is responsible for the transmitting the perception of pain and of various sensations that originate in internal organs?
The spinoreticular tract
Corticospinal fibers (in the Lateral corticospinal tract) from the parietal lobe terminate mainly in the ______
a. dorsal horn
b. intermediate gray matter and the ventral horn
c. Muscle spindles
d. Nucleus of Onuf
a. dorsal horn
The spinothalamic tract conducts impulses concerned with ________.
tactile, thermal, and painful sensations
Ventral spinocerebellar tract fibers are:
a. ascending
b. descending
c. Mostly crossed twice
d. Mostly uncrossed
a. ascending
c. Mostly crossed twice
The ____ tract is concerned with spinovisual reflex.
a. Reticulospinal tract
b. The spinoreticular tract
c. Unmyelinated hypothalamospinal fibers
d. Lateral corticospinal tract
e. Ventral spinocerebellar tract
f. The spinotectal tract (or spinomesencephalic tract)
f. The spinotectal tract
List the four components that constitute the ventral funiculus.
I. The ventral corticospinal tract
II. The vestibulospinal tract
III. Reticulospinal tracts
IV. Small tracts (remaining tracts)
What is the function of the ventral spinocerebellar tract?
It convey sensory information (mainly proprioceptive) from one lower limb to the same side of the cerebellum (similar function with dorsal
spinocerebellar tract).
Which tract mediates equilibratory reflexes?
The vestibulospinal tract
equilibratory reflexes are triggered by the activity of the vestibular apparatus of the internal ear and effected chiefly by the axial musculature and the
extensor muscles of the limbs.
Where are Reticulospinal tracts located?
ventral funiculus and
the ventral half of the lateral funiculus (Ventrolateral Fasciculus)
The vestibulospinal tract is:
a. ascending
b. descending
c. Crossed (contralateral)
d. Uncrossed (ipsilateral)
b. descending
d. Uncrossed (ipsilateral)
arises from the lateral vestibular nucleus in the
medulla and descends in the ventrolateral and ventral white matter of the spinal cord
Which is the odd one out and why?
a. ventral spinocerebellar tract
b. ventral corticospinal tract
c. reticulospinal tracts
d. vestibulospinal tract
a. ventral spinocerebellar tract
because it is located in the ventrolateral funiculus, the others are located in the ventral funiculus. It is also an ascending pathway, while the others are descending
What are the functions of the reticulospinal tracts?
• It is one of the descending pathways through which the brain directs and controls the activity of motor neurons (activities that do
not require constant conscious effort).
• The descending bundle of the lateral horn in the upper 7 or 8 thoracic segments are excitatory to the preganglionic sympathetic
neurons that control blood vessels and sweat glands throughout the body (autonomic function)
Monosynaptic reflex arcs have ______ synapse(s) and involve ______ neuron(s)
Monosynaptic reflex arcs have one synapse(s) and involve two neuron(s)
The stretch reflex is an important postural reflex, monitored through:
a. Merkel endings
b. Nociceptors
c. Neuromuscular spindles
d. Golgi tendon organs
e. Pacinian corpuscles
c. Neuromuscular spindles
d. Golgi tendon organs
What is the flexor reflex?
consists of the withdrawal of a limb in response to a painful stimulus.
At least three neurons are involved (polysynaptic)
