Chapter 6 : Spinal Cord (2) Flashcards
- All of the following statements concerning the substantia gelatinosa are correct EXCEPT
(A) it is found at all spinal cord levels
(B) it is a sensory nucleus
(C) it plays a role in mediating pain and temperature
(D) it is homologous to the spinal trigeminal nucleus
(E) it is greatly reduced in size at sacral levels
l-E. The substantia gelatinosa is greatly enlarged at sacral levels. It is a sensory nucleus found at all cord levels. It mediates pain and temperature and is homologous to the spinal trigeminal nucleus.
- Which statement concerning the dorsal root ganglion is FALSE?
(A) It contains pseudounipolar neurons
(B) It is located within the intervertebral foramen
(C) It contains neurons of neural crest origin
(D) It usually is missing at CI
(E) It lies within the subarachnoid space
2-E. The dorsal root ganglion contains large (proprioception) and small (pain and temperature)
pseudounipolar neurons of neural crest origin and lies within the intervertebral foramen. It usually is absent in the first cervical nerve and in the coccygeal nerve.
- Which statement concerning the lateral horn is FALSE?
(A) It receives viscerosensory input
(B) It is found at the level of the phrenic nucleus
(C) It is coextensive with the nucleus dorsalis of Clarke
(D) It contains a visceromotor nucleus
(E) It corresponds to Rexed lamina VII
3-B. The lateral horn extends from (C8) Tl to L3. The phrenic nucleus extends from C3 to C6.
The nucleus dorsalis of Clarke is coextensive with the lateral horn and its intermediolateral nucleus or cell column. Rexed lamina VII (lamina intermedia) includes the sympathetic intermediolateral nucleus, the parasympathetic sacral nucleus (S2-S4), and the nucleus dorsalis of Clarke.
- All of the following statements concerning the spinal cord are correct EXCEPT
(A) it represents 2% of brain weight
(B) it terminates in the adult at VL1-VL2
(C) it lies within the subarachnoid space
(D) it terminates in the newborn at VS2
(E) it contains 31 pairs of spinal nerves
4-D. In the newborn, the spinal cord ends at the level of the third lumbar vertebra (VL3). In the adult, the spinal cord ends at the level of the interspace between the first and second lumbar vertebrae (VL1-VL2). In the adult, the dural cul-de-sac ends at the level of the second sacral vertebra (VS2).
- All of the following statements concerning spinal nerves are correct EXCEPT
(A) dorsal roots contain sensory input
(B) ventral roots contain motor output
(C) all spinal nerves have gray communicating rami
(D) all spinal nerves have white communicating rami
(E) the first cervical nerves frequently have no dorsal roots
5-D. White communicating rami are found only at thoracolumbar levels of the spinal cord (T1-L3); they contain myelinated preganglionic sympathetic fibers and myelinated GVA fibers (from splanchnic nerves). Gray communicating rami contain unmyelinated postganglionic sympathetic fibers and contribute to all spinal nerves. The first cervical nerve and the coccygeal nerve usually have no dorsal (sensory) roots.
- All of the following statements concerning the cauda equina are correct EXCEPT
(A) it contains motor fibers
(B) it contains sensory fibers
(C) it is found in the subarachnoid space
(D) it is derived from the pia
(E) it is found below the first lumbar vertebra
6-D. The cauda equina consists of lumbosacral nerve roots that descend below the level of the
conus medullaris, within the subarachnoid space, to exit through their respective intervertebral
or sacral foramina. Dorsad roots contain sensory fibers; ventral roots contain motor fibers.The cauda equina syndrome affects the lumbosacral nerve roots, producing both sensory and motor symptoms.
- All of the following statements concerning the myotatic reflex are correct EXCEPT
(A) it is a monosynaptic and ipsilateral reflex
(B) it is a muscle stretch reflex
(C) it includes a muscle spindle
(D) it includes a ventral horn motor neuron
(E) the cell body of afferent nerve fiber is found in the dorsal horn
7-E. The myotatic reflex is a monosynaptic and ipsilateral muscle stretch reflex (MSR;incorrectly
called a deep tendon reflex). The afferent limb consists of a muscle spindle (receptor) and a la fiber (axon) of a dorsal root ganglion neuron; the efferent limb consists of the axon of a ventral horn alpha motor neuron and the innervated striated muscle fibers (effector). The quadriceps (patellar) and triceps surae (ankle) muscle stretch reflexes are examples of myotatic reflexes.
Match each of the statements below to the structure most closely associated with it. (A) Dorsal intermediate septum (B) Ventral lateral sulcus (C) Dorsal median sulcus (D) Dorsal lateral sulcus (E) Ventral median fissure
- Contains the sulcal branch of an artery
8-E. The ventral median fissure contains the sulcal branch of the ventral (anterior) spinal artery.
Match each of the statements below to the structure most closely associated with it. (A) Dorsal intermediate septum (B) Ventral lateral sulcus (C) Dorsal median sulcus (D) Dorsal lateral sulcus (E) Ventral median fissure
- Receives dorsal roots
9-D. The dorsal lateral sulcus receives the dorsal roots.
Match each of the statements below to the structure most closely associated with it. (A) Dorsal intermediate septum (B) Ventral lateral sulcus (C) Dorsal median sulcus (D) Dorsal lateral sulcus (E) Ventral median fissure
- Is not found at lumbar levels
10-A. The dorsal intermediate septum extends from CI to T6. It is diagnostic for cervical and
upper thoracic cord segments.
Match each of the statements below to the structure most closely associated with it. (A) Dorsal intermediate septum (B) Ventral lateral sulcus (C) Dorsal median sulcus (D) Dorsal lateral sulcus (E) Ventral median fissure
- Is located between the fasciculus gracilis and the fasciculus cuneatus
11-A. The dorsal intermediate septum separates the fasciculus gracilis from the fasciculus cuneatus. It is indicative of the cervical and upper thoracic cord.
Match each of the statements below to the structure most closely associated with it. (A) Dorsal intermediate septum (B) Ventral lateral sulcus (C) Dorsal median sulcus (D) Dorsal lateral sulcus (E) Ventral median fissure
- Is the zone of emergence for ventral roots
12-B. The ventral lateral sulcus is the zone of emergence for the ventral roots.
Match each characteristic below with the spinal cord level it best describes. (A) Cervical cord (B) Upper thoracic cord (C) Lumbar cord (D) Lower thoracic cord (E) Coccygeal cord (F) Sacral cord
- Contains preganglionic parasympathetic neurons
13-F. The sacral cord contains the sacral parasympathetic nucleus (S2-S4); this gives rise to
preganglionic fibers that synapse in the intramural ganglia of the pelvic viscera
Match each characteristic below with the spinal cord level it best describes. (A) Cervical cord (B) Upper thoracic cord (C) Lumbar cord (D) Lower thoracic cord (E) Coccygeal cord (F) Sacral cord
- Contains massive ventral horns and dorsal intermediate sulcus
14-A. The cervical cord contains massive ventral horns, which give rise to the brachial plexus (C5-C8). The dorsal intermediate sulcus and septum are also indicative of cervical cord levels.
Match each characteristic below with the spinal cord level it best describes. (A) Cervical cord (B) Upper thoracic cord (C) Lumbar cord (D) Lower thoracic cord (E) Coccygeal cord (F) Sacral cord
- Has a ciliospinal center of Budge
15-B. The ciliospinal center of Budge is found in the lateral horn at Tl. This sympathetic nucleus innervates the radial muscle of the iris (dilatator pupillae) and the nonstriated superior and inferior tarsal (Miiller) muscles