S2 Neuro Exam 2: Spinal Cord 1

Front 1

The spinal cord extends from the foramen magnum to where?

Back 1

the L1-L2 intervertebral disc

Front 2

Where does the spinal cord extend to in newborns?

Back 2

L3

Front 3

During what month of development does the cord fill the vertebral column?

Back 3

3rd month

*vertebral column outgrows spinal cord during development

Front 4

The spinal cord consists of an area that primarily contains ____________surrounded by ______________that are primarily ascending (spinal cord to brain) and descending (brain to spinal cord).

Back 4

cell bodies (butterfly shaped, grey matter)


collections of axons (white matter; funiculi, tracts, fasciculi)

Front 5

Contrary to its name, axon white matter (myelin) stains ____________ & the nerve cell bodies are unstained (light grey or white)

Back 5

dark gray or black

Front 6

After the neural tube forms (neurulation) and closes, the neuroepithelial cells in the _______________ begin to form neuroblasts & glioblasts

Back 6

ventricular zone

Front 7

What will the neuroblasts and glioblasts form?

Back 7

future neurons and neuroglial cells of spinal cord

Front 8

The mantle zone continues to develop into 4 dorsoventral columns on each side the _____________ & __________ separated by the sulcus limitans

Back 8

alar and basal plates

Front 9

The _______________ of the developing spinal cord, will become the gray matter

Back 9

intermediate or mantle zone

*btwn alar & basal plates (has components of both, ANS)

Front 10

The white matter areas of the spinal cord develop in the _______________, a layer of neuroblast processes that forms outside of the mantle zone of the neural tube.

Back 10

marginal zone

*eventually neuron processes from brainstem & forebrain will contribute to mantle zone

Front 11

The marginal zone also contains the developing glial cells that will do what/?

Back 11

(astrocytes & oligodendrocytes)
- will form the structure of the spinal white matter, and eventually myelinate the long tracts of the spinal cord (later) in pre and post natal development.

Front 12

The alar lamina develop into _____________
& the basal lamina develop into ___________

Back 12

dorsal horns (sensory neurons)
ventral horns (motor neurons)

Front 13

The ventricular zone will form ependymal cells of the __________________

Back 13

central (spinal) canal
^begins at 4th ventricle

Front 14

What are the 2 enlargements of the spinal cord that correspond to innervation of limbs?

Back 14

Cervical Enlargement – C4-T1
Lumbosacral Enlargement – L1- S2

Front 15

The ___________penetrates deeply into the cord, extending almost to the middle. It contains sulcal branches of the anterior spinal artery.

Back 15

anterior median fissure

Front 16

Ventral roots leave the cord from the ________________

Back 16

anterolateral sulcus

(less well defined)

Front 17

The _______________marks the site of entry of the dorsal roots, ie., the dorsal root entry zone.

Back 17

posterolateral sulcus

Front 18

The ___________________ is located in the midline on the dorsal aspect of the cord. It contains a delicate pial partition, the posterior median septum

Back 18

posterior median sulcus

Front 19

In the upper thoracic and cervical spinal cord, the ___________________ and septum lie between the posterior median and posterior lateral sulci. This sulcus partially divides the dorsal columns.

Back 19

posterior intermediate sulcus

Front 20

There are ___ pairs of spinal nerves. Each spinal nerve is formed by the merger of dorsal and ventral roots at a particular spinal cord level.

Back 20

31 (8 C, 12 T, 5 L, 5 S, 1 Co)

**C1 & Co1 may lack dorsal root contribution

Front 21

The portion of the spinal cord that gives rise to the spinal nerve is referred to as a ___________

Back 21

segment

Front 22

Spinal nerves C1-C7 pass (below/above) the correspondingly numbered vertebrae.

What about C8?

Back 22

above

Spinal nerve C8 emerges from between the C7 and T1 vertebrae

Front 23

Subsequent spinal nerves emerge (below/above) the correspondingly numbered vertebrae

Back 23

below

(e.g., spinal nerve T4 travels between T4 and T5 vertebrae.

Front 24

A single spinal cord segment innervates a specific ____________ (skin) & ___________ (sleletal muscle)

Back 24

dermatome & myotome

Front 25

Spinal nerve component:
Somatic sensory fibers (GSA)

Back 25

GSA- Neurons located in dorsal root ganglia (DRG) convey information from receptors in skin, muscle, tendons, and joints.

Front 26

Spinal nerve component:
Visceral sensory fibers (GVA)

Back 26

GVA- nerve fibers are from mechanoreceptors and nociceptors within the viscera (autonomic afferents). Cell bodies of these neurons are found within the DRG, as well.

Front 27

Spinal nerve component:
Somatic motor fibers (GSE)

Back 27

GSE- axons arise from motor neurons within the spinal cord (ventral horn) and innervate body musculature involved in volitional motor activity. Single neuron pathway from spinal cord to muscle.

Front 28

Spinal nerve component:
Visceral motor fibers (GVE)

Back 28

GVE- Axons of neurons within the spinal cord that terminate in autonomic ganglia, i.e., sympathetic and parasympathetic ganglia. Postganglionic neurons then innervate smooth muscle, cardiac muscle and glands. Two neuron pathway.

Front 29

What are the 3 meninges surrounding spinal cord (inner---> outer)?

Which is the thickest/toughest?

Back 29

pia--> arachnoid---> dura mater


dura mater

Front 30

Where does the dura extend to?

Back 30

from the foramen magnum down to S2 vertebrae

Front 31

The dura is separated from bone of the vertebral canal by the ___________, which contains fat, loose connective tissue and internal venous plexuses

Back 31

epidural space

*local anesthetic drugs are injected into this space

Front 32

what layer forms a barrier preventing substances from crossing membrane?

Back 32

arachnoid mater

Front 33

__________ extend through the CSF-filled subarachnoid space to the pia mater below.

Back 33

Arachnoid trabeculae

"spider web"

*arachnoid can seperate from dura and form subdural space

Front 34

_________is the innermost meningeal membrane that invests the surface of the CNS, following its contours. It also follows the nerve roots out to the spinal nerves.

Back 34

Pia mater

Front 35

What are the 2 specializations of the pia mater and what is their purpose?

Back 35

denticulate ligaments & filum terminale
-serve to stabalize the spinal cord

Front 36

_______________ are fibrous bands of pia found on each side of the spinal cord between the ventral and dorsal spinal roots.
The apices of these triangular, tooth-like processes pierce the arachnoid and attach to the dura. There are usually 21 on each side

Back 36

Denticulate (dentate) ligaments

Front 37

The___________________ is a thin thread of pia mater that arises from the caudal end of the spinal cord, the conus medullaris, and travels inferiorly to caudal tip of the thecal sac at S2.

Back 37

filum terminale internum

Front 38

The expansion of the spinal subarachnoid space caudal to the conus medullaris is called the what?

Back 38

the lumbar cistern

Front 39

The ____________________ is a continuation of this pial thread that pierces through the thecal sac and extends caudally. The pia becomes enclosed by dura, which attaches to the coccyx

Back 39

filum terminale externum

Front 40

Q: Postganglionic sympathetic fibers enter spinal nerves via what?

Back 40

gray ramus communicans