Spinal Cord & Spinal Nerves

Question 1

The ___ is nerve tissue continuous with that of the brain, extending inferiorly from the brain at the level of the foramen magnum.

Answer 1

spinal cord

Question 2

The bony covering of the spinal cord is formed by the ____. The spinal cord lies within the spinal cavity formed by the vertebral foramina of the stacked vertebrae.

Answer 2

vertebral column.

Question 3

The outermost of three membranous coverings, or meninges (singular, meninx), of the spinal cord is the tough, skin-like ___.

Answer 3

dura mater

Question 4

The ___ are continuous with the meninges surrounding the brain.

Answer 4

spinal meninges

Question 5

Categories under meninges

Answer 5

Dura mater
Arachnoid mater
Subarachnoid space
Pia mater

Question 6

Deep to the dura mater is a much thinner meninx, the spidery ___.

Answer 6

arachnoid mater

Question 7

The space deep to the arachnoid, the ___, is filled with circulating cerebrospinal fluid (CSF) in life. The CS has been drained from your specimen.

Answer 7

subarachnoid space

Question 8

The deepest meninx, the delicate ___, is a thin, vascular membrane adhering to the surface of the spinal cord.

Answer 8

pia mater

Question 9

The ____ is a deep groove on the anterior surface of the human spinal cord (along the midline). This fissure is analogous to that on the ventral surface of the ox spinal cord.

Answer 9

anterior median fissur

Question 10

The ___ is a somewhat shallower groove along the dorsal surface of the spinal cord.

Answer 10

posterior median sulcus

Question 11

A ____ is seen in the C5 to Tl segments of the spinal cord, and a similar ____ is found in the L2 to S3 segments.

Answer 11

cervical enlargement, lumbar enlargement

Question 12

Inferior to the lumbar enlargement, the spinal cord tapers to a cone-shaped end called the

Answer 12

conus medullaris.

Question 13

TRUE or FALSE

The spinal cord proper does not extend below the L1 vertebra.

Answer 13

True

Question 14

This group of spinal nerve roots, resembling a horse’s tail, is called the

Answer 14

cauda equina

Question 15

Spinal cord extends from the foramen magnum at the base of the skull to the ___ lumbar vertebra;

Question 16

Spinal cord protected by vertebral column; its inferior end where the spinal nerves exit is called ___ (resembles a horse’s tail)

Answer 16

cauda equina

Question 17

occurs when there is dysfunction of multiple lumbar and sacral nerve roots of the cauda equina.

Most commonly results from a massive herniated disc in the lumbar region. A single excessive strain or injury may cause a herniated disc, however, many disc herniations do not necessarily have an
identified cause.

Answer 17

Cauda equina syndrome

Question 18

•Spinal lesions and tumors
•Spinal infections or inflammation
•Lumbar spinal stenosis
•Violent injuries to the lower back (gunshots, falls, auto
accidents)
•Birth abnormalities
•Spinal arteriovenous malformations (AVMs)
•Spinal hemorrhages (subarachnoid, subdural, epidural)
•Postoperative lumbar spine surgery complications
•Spinal anesthesia

Answer 18

Potential Causes of CES

Question 19

Tests that May be Helpful in Diagnosing CES

Extremely important to assess for cauda equina syndrome.

Answer 19

Patient history and physical exam

Question 20

Tests that May be Helpful in Diagnosing CES

A diagnostic test that produces three-dimensional images of body structures using magnetic fields and computer technology. ___ produces images of the spinal cord, nerve roots and surrounding areas.

Answer 20

Magnetic resonance imaging (MRI)

Question 21

An x-ray of the spinal canal that gives good definition of the bone. If CES is
secondary to bone collapse from trauma or cancer, this study can help define that.
Visualization of the discs are not as easily seen on ___ scan. If no MRI is available, this study can give information helpful to evaluate the anatomy of the region, particularly if done in combination with a myelogram described below.

Answer 21

CT Scan

Question 22

An X-ray of the spinal canal following injection of a contrast material into
the surrounding cerebrospinal fluid spaces; can show displacement on the spinal cord or spinal nerves due to herniated discs, bone spurs, tumors, etc.

Answer 22

Myleogram

Question 23

Mainly collection of cell bodies at the center of spinal cord that is shaped like letter H or butterfly; consists of four structures

Answer 23

Gray Matter

Question 24

contain axons which synapse with interneurons

Answer 24

Posterior Horns

Question 25

contains cell bodies of pseudounipolar sensory neurons & axons that originate in the periphery of the body; passes through spinal nerves & dorsal roots of this horn

Answer 25

Dorsal Root Ganglion

Question 26

contain somatic neurons

Answer 26

o Anterior Horns

Question 27

contain autonomic neurons

Answer 27

o Lateral Horns

Question 28

fluid-filled space in the center of the cord

Answer 28

o Central Canal

Question 29

located at the superficial portion; each half is organized into three columns: dorsal / posterior, ventral / anterior, and lateral columns. Each column contains two nerve tracts/pathways

Answer 29

White Matter

Question 30

consist of axons that conduct action
potentials toward the brain

Answer 30

o Ascending Tracts

Question 31

consist of axons that conduct action
potentials away from the brain

Answer 31

o Descending Tracts

Question 32

arise along spinal cord from union of dorsal & ventral roots.

All contain axons from both sensory and somatic motor neurons (mixed nerves)

Categorized by region of vertebral column from which they emerge – cervical (C1 to C8), thoracic (T1 to T12), lumbar (L1 to L5), sacral (S1 to S5), and
coccygeal (Co) – ___ pairs in total

Answer 32

Spinal nerves

31

Question 33

area of skin supplied with sensory innervation by a pair of spinal nerves; each spinal nerves has specific cutaneous sensory distribution
(except C1)

Answer 33

Dermatome

Question 34

area where neurons of spinal nerves come together & intermingle

Answer 34

Plexus

Question 35

Arise along the lateral side of the vertebra

Formed by union of dorsal and ventral roots

Answer 35

Spinal nerve

Question 36

TRUE or FALSE

All spinal nerves are mixed (both sensory and motor) in function

Answer 36

True

Question 37

Most of the spinal nerves are organized in groups “PLEXUSES”

Answer 37

1. Cervical Plexuses
2. Brachial Plexuses
3. Lumbosacral Plexuses

Question 38

Arises from spinal nerves C1-C4

Innervates several muscles on the neck

Innervates the ___ nerve

Answer 38

Cervical plexus

Phrenic

Question 39

• Arises from spinal nerves C5-T1
• Forms 5 major nerve of the upper extremities

Answer 39

Brachial plexus

Question 40

Shoulder muscle

Answer 40

Axillary nerve

Question 41

All muscles of the posterior arm and forearm

Answer 41

Radial nerve

Question 42

Anterior muscle of the arm

Answer 42

Musculocutaneous nerve

Question 43

2 forearm muscles and the intrinsic muscle of the hand

Answer 43

Ulnar nerve

Question 44

Muscles of the anterior forearm

Answer 44

Median nerve

Question 45

Axillary nerve
Radial nerve
Musculocutaneous nerve
Ulnar nerve
Median nerve

Answer 45

Brachial plexus

Question 46

• Arises from spinal nerves L1-S4

Answer 46

Lumbosacral plexus

Question 47

Innervate the muscles of the inner thigh and skin

Answer 47

Obturator nerve

Question 48

Muscles of the anterior thigh and skin (+skin of medial side of the leg)

Answer 48

Femoral nerve

Question 49

Posterior thigh muscles, anterior and posterior leg muscles, and most of intrinsic foot muscle

Answer 49

Tibial nerve

Question 50

Innervate the muscles of the inner thigh and skin

Answer 50

Common fibular nerve

Question 51

the largest nerve in the body, running from the lower back down the back of each leg

Answer 51

Sciatic nerve

Question 52

Combination of common fibular and tibial nerve

Answer 52

Sciatic nerve