CHAPTER 14 TEST REVIEW

Question 1

typical adult spinal cord (diameter, length)

Answer 1

Typical adult spinal cord: ¾ inch diameter, 16-18 inches in
length

Question 2

4 parts of the spinal cord

Answer 2

Four parts: cervical, thoracic, lumbar, and sacral

Question 3

nerve

Answer 3

cablelike bundle of axons

Question 4

connective tissue wrappings

Answer 4

Epineurium (around nerve), perineurium (around fascicle),
endoneurium (around axon)

Question 5

number of spinal nerves

Answer 5

31 pairs

Question 6

cuada equina

Answer 6

• Spinal cord ends at inferior border of L1 vertebra
• Roots of lumbar, sacral, and coccygeal spinal nerves extend
  inferiorly from conus medullaris, exit at appropriate location
• These roots form a structure called the cauda equina

Question 7

Clinical View: Lumbar Puncture

Answer 7

Procedure for obtaining CSF for medical diagnosis
Needle passes through
* Skin, back muscles, ligamentum flavum
* Epidural space, dura mater
* Arachnoid mater into subarachnoid space
Adult spinal cord ends at L1
* Lumbar puncture below this, just above or below L4
* Spinous process of L4 at highest points of iliac crests

Question 8

Clinical View: Treating Spinal Cord Injuries

Answer 8

May leave individuals paralyzed and unable to perceive
sensations
Prompt use of steroids after injury
* May preserve muscle function
Early antibiotics
* Have reduced number of deaths due to pulmonary and
urinary infections
Neural stem cells
* May be used in future to regenerate CNS axons

Question 9

Clinical View: Shingles (Herpes Zoster)

Answer 9

• Reactivation of varicella-zoster (chickenpox) infection
• Virus remaining latent in posterior root ganglia
• Reactivated, travels through sensory axons to dermatome
• Rash and blisters along the dermatome
• Burning and tingling pain
• Antiviral medication to reduce severity
• Vaccine to prevent or reduce disease severity

Question 10

distribution of the spinal nerves

Answer 10

After intervertebral foramen, spinal nerve splits
Posterior (dorsal) ramus—small branch
* Innervates muscles and skin of back
Anterior (ventral) ramus—large branch
* Splits into multiple other branches
* At different levels, this ramus innervates anterior and lateral
trunk, upper limb, lower limb
* Participates in plexuses
Rami communicantes—small branches of autonomic fibers
* Extend between spinal nerve and sympathetic trunk
ganglion
* Ganglia interconnected in sympathetic trunk parallel to vertebral
column
Dermatomes
* Segment of skin supplied by single spinal nerve
* Some overlap in innervated regions

Question 11

hypoactive/hyperactive reflex

Answer 11

Hypoactive reflex: diminished or absent
* May indicate damage to spinal cord, or muscle disease, or damage
to neuromuscular junction

Hyperactive reflex: abnormally strong response
* May indicate damage to brain or spinal cord, especially if
accompanied by clonus (rhythmic oscillating movements with
reflex testing)