Spinal cord Flashcards
The artery of Adamkiewicz (select 2):
a. more commonly arises from the left side
b. provides collateral circulation to the posterior spinal cord
c. usually arises between T4 and T8
d. occlusion can cause flaccid paralysis
a. more commonly arises from the left side
d. occlusion can cause flaccid paralysis
The artery of Adamkiewicz originates between
T8-T12
left side typically between T11-T12
The spinal cord’s circulation consists of:
posterior spinal arteries (2)
anterior spinal artery (1)
radicular arteries (6-8)
The anterior spinal artery perfuses the
anterior 2/3 of the spinal cord
The radicular arteries perfuse the
spinal arteries in the thoracolumbar region of the spinal cord
The posterior spinal arteries perfuse
the posterior 1/3rd of the spinal cord
Interruption of radicular flow can cause
ischemic injury to the corresponding spinal cord segments
The ____________ supply the anterior and posterior spinal arteries in the cervical region of the spinal cord.
vertebral arteries
The most important radicular artery is
the artery of Adamkiewicz
The artery of Adamkiewicz perfuses the
anterior spinal cord in the thoracolumbar region
An aortic cross-clamp placed above the artery of Adamkiewicz can cause
ischemia to the lower portion of the anterior spinal cord resulting in anterior spinal artery syndrome (Beck’s syndrome)
Anterior spinal artery syndrome is also known as
Beck’s syndrome
Classic signs of anterior spinal artery syndrome include
flaccid paralysis of the lower extremities
bowel and bladder dysfunction
loss of temperature and pain sensation
preserved touch and proprioception
The corticospinal tract is perfused by
the anterior blood supply. This explains why the patient presents with flaccid paralysis of the lower extremies
The spinothalamic tract is perfused by
the anterior blood supply. This explains why the patient loses pain and temperature sensation
Autonomic motor fibers are perfused by
the anterior blood supply. This explains why the patient experiences bowel and bladder dysfunction
The dorsal column is perfused by the
posterior blood supply. This explains why touch and proprioception are preserved
List 3 spinal pathways that are supplied by the anterior spinal artery
corticospinal tract
autonomic motor fibers
spinothalamic tract
List 1 spinal pathway that is supplied by the posterior spinal artery.
dorsal column
The spinal cord links the
peripheral nerves to the brain
Motor and autonomic neurons exit the spinal cord via
the ventral nerve root
Sensory neurons enter the spinal cord via
the dorsal root
A _______ is a collection of cell bodies that reside outside of the CNS
ganglion
The white matter of the spinal cord contains the
axons of the ascending and descending tracts
A tract is a
group of fibers inside the white matter in the CNS that relay information up or down the spinal cord or to and from the brain
The grey matter of the spinal cord contains
neuronal cell bodies and they’re subdivided into 10 laminae
Laminae 1-6 are _____-
sensory
Laminae 7-9 are
motor
Lamina 10 is
central commissures (cross-over) area
The grey matter is larger in two specific regions of the spinal cord:
C5-C7
L3-S2
The region of cervical enlargement of the grey matter contains the
cell bodies for the neurons that supply the upper extremities
The region of lumbar enlargement of the grey matter contains the
cell bodies for the neurons that supply the lower extremities
The corticospinal tracts travel from
the cortex to the spine
The corticospinal tracts are _______pathways
motor
The spinothalamic tracts travel from
the spine to the thalamus
The spinothalamic tracts are ______- pathways
sensory
All of the following statements about the dorsal column are true EXCEPT:
a. the first-order neuron enters the spinal cord via the dorsal root ganglia
b. it transmits nociceptive input to the thalamus
c. the second order neuron decussates in the medulla
d. it transmits sensory information faster than the anterolateral system
b. it transmits nociceptive input to the thalamus
the anterolateral system, not the dorsal column, transmits nociceptive input to the thalamus
The dorsal column is a ________________ pathway
Three-neuron sensory
The dorsal column transmits:
fine touch
proprioception
vibration
pressure (fine degree of intensity)
The dorsal column consists of
large, myelinated, rapidly conducting fibers
The dorsal column transmits sensory information faster than
the anterolateral system
The Merkel’s discs mechanoreceptors function is
continuous touch
The Ruffini’s endings mechanoreceptors function is
proprioception
prolonged touch and pressure
The Pacinian corpuscles mechanoreceptors function is
vibration
The Meissner’s corpuscles mechanoreceptor function is
two-point discriminative touch & vibration
First order neurons enter
the spinal cord through the dorsal root ganglion
First-order neurons relays sensory information from the
dorsal column to the medulla
First-order neurons ascend the spinal cord on the
ipsilateral side (same side that it entered)
The first-order neuron synapses with the second-order neuron in the
medulla
Second-order neurons cross to the contralateral side in
the medulla
Second-order neurons ascend towards th
thalamus via the medial lemniscus
Second-order neurons are joined by the
trigeminal nerve (which provides sensation to the face and head)
Second-order neurons synapse with the third-order neuron in the
thalamic realy station
