Chapter 13 - Spinal Cord and Nerves

Question 1

• tunnel down through middle of spinal cord in the gray matter

Answer 1

Central canal

Question 2

– large fissure in the midline on the ventral (anterior) side of the cord

Answer 2

Anterior median fissure

Question 3

fold at the midline on the dorsal (posterior) side of the cord

Answer 3

Posterior median sulcus

Question 4

– large swelling in the dorsal

roots of the spinal nerves; where the soma of afferent neurons is found

Answer 4

Dorsal root ganglion (also known as posterior root ganglion)

Question 5

– enlarging of spinal cord in area where sensory fibers enter and
motor fibers leave for innervation of arms and hands; roughly C3 to T2 with largest
area at C5-C6.

Answer 5

Cervical enlargement

Question 6

enlarging of spinal cord in area where sensory fibers enter and
motor fibers leave for innervation of hips, legs and feet; roughly T11 to conus
medullaris

Answer 6

Lumbar enlargement

Question 7

myelinated tracts (myelin appears white)

Answer 7

White matter

Question 8

soma of neurons

Answer 8

Gray matter

Question 9

connection between R and L side of spinal cord within white

matter

Answer 9

White commissure

Question 10

• connection between R and L side of spinal cord within gray matter

Answer 10

Gray commissure

Question 11

contains neurons receiving synapses from afferent

(sensory) neurons

Answer 11

Posterior or dorsal horns

Question 12

contains the soma of spinal motor neurons for
somatic nervous system; these send out axons that form nerve fibers
connecting to skeletal muscle

Answer 12

Anterior or ventral horns

Question 13

contains the soma of autonomic motor
neurons; these send out axons that form nerve fibers that connect via
ganglionic neurons to various internal organs and glands.

Answer 13

Lateral horn of gray matter

Question 14

– the membrane tightly attached to the surface of the spinal cord (and brain)

Answer 14

pia mater

Question 15

– the middle of the 3 meninges; it attaches pia mater with fibrous
extensions that look like a spider’s web in cross-sections

Answer 15

arachnoid mater

Question 16

the tough outer membrane that wraps around the spinal cord and brain; also
called the dural sheath

Answer 16

dura mater

Question 17

the space between vertebrae and dura mater (outside dural sheath) and
thus unique to the spinal cord and column; this is where epidural anesthetics should be
injected for epidural anesthesia; it contains blood vessels, adipose tissue and connective
tissue

Answer 17

Epidural space

Question 18

is the space between the arachnoid mater and the pia mater in both
brain and spinal cord; it is filled with cerebrospinal fluid (CSF).

Answer 18

Subarachnoid space

Question 19

samples CSF by inserting a needle through the

meninges and into the space inferior to conus medullaris where cauda equine resides

Answer 19

lumbar puncture (also called spinal tap

Question 20

are named consecutively for the segment (cervical, thoracic, lumbar,
sacral, coccygeal) and then numbered from superior to inferior direction running down
the cord (see chart above).

Answer 20

Spinal nerves

Question 21

conducts sensory information

Answer 21

Dorsal root

Question 22

where the

soma of these sensory neurons is located.

Answer 22

dorsal root ganglion

Question 23

contains neurons receiving

the sensory input.

Answer 23

dorsal horn

Question 24

contains somatic motor neurons

Answer 24

Ventral root

Question 25

contains

autonomic motor neurons.

Answer 25

lateral horn

Question 26

conduct sensory information to the brain via ascending tracts

Answer 26

Posterior funiculi

Question 27

conduct motor information from the brain via descending tracts

Answer 27

Anterior funiculi

Question 28

• Bundles of axons in the funiculi

Answer 28

Fascicles

Question 29

The gracile and cuneate fasciculi (in posterior)

carry bulk of

Answer 29

somatosensory/visceral sensory information.

Question 30

which there is crossing in the spinal cord through the

gray matter commissure.

Answer 30

Anterolateral pathway

Question 31

2 types of ascending pathways

Answer 31

Anterolateral and posterior column

Question 32

crosses at the decussation of the pyramids, the

fibers then synapse onto motor neurons at the ventral horn (90% of fibers).

Answer 32

Lateral Corticospinal tract

Question 33

tract crosses at the white commissure; the fibers then

synapse onto motor neurons at the ventral horn (10% of fibers

Answer 33

Anterior Corticospinal

Question 34

2 types of descending pathways

Answer 34

Lateral corticospinal tract and anterior corticospinal

Question 35

chain of ganglia attached to the body of thoracic vertebrae in thoracic/lumbar regions.

Answer 35

Sympathetic Chain

Question 36

branch goes back to the spinal cord, innervating the meninges

Answer 36

Meningeal branch

Question 37

– innervates muscles and joints in spine/back

Answer 37

Dorsal ramus

Question 38

– innervates skin of ventral/lateral portions of trunk

Answer 38

Ventral ramus

Question 39

carries autonomic fibers that communicate with sympathetic

chain

Answer 39

Connecting rami

Question 40

the point in which some spinal nerves join together to form one large peripheral nerve

Answer 40

nerve plexus

Question 41

• A map of the sensory area of the body’s skin that sends signals to the spinal cord along a
particular spinal nerve.

Answer 41

Dermatomes

Question 42

• Specialized muscle cells called intrafusal

muscle fibers are embedded and innervated in the muscle near tendons.

Answer 42

Muscle Spindle fiber (stretch receptors)

Question 43

sensory organ embedded in the tendon that sends afferent
nerve signals about the speed and direction of movement, load on muscle and any
detected overstretch of the muscle

Answer 43

Golgi Tendon Organ

Question 44

s involve a response of a muscle to a stimuli without sending the nerve
impulses to the cortex. They occur with a few synapses in the spinal cord or in the
brainstem.

Answer 44

Reflex arcs

Question 45

generate fast, automatic responses.

Answer 45

Reflex arcs

Question 46

type of spinal reflex arc where you withdraw from

pain.

Answer 46

Withdrawal reflexes