Exam 2: Spinal Cord

Question 1

Spinal Cord

Answer 1

• rests within vertebral canal=vertebral foramina stacked on top of one another
• from foramen magnum to L1 vertebra

Question 2

Spinal Cord Morphology

Answer 2

• oval in cross section
• enlarged in two areas
• cervical Enlargement: contains neurons that innervate upper limb
• lumbar enlargement: contains neurons that innervate lower limb

Question 3

Conus Medullaris

Answer 3

-pointed end of spinal cord

Question 4

Cauda Equina

Answer 4

-collection of nerve roots coming off of conus medullaris

Question 5

Filum Terminale

Answer 5

-thin strand of pia matter that anchors conus medullaris to coccyx.

Question 6

31 pairs of spinal nerves

Answer 6

• 8 cervical (C1-C8)
• 12 thoracic (T1-T12)
• 5 lumbar (L1-L5)
• 5 sacral (S1-S5)
• 1 coccygeal (Co1)
• will exit vertebral canal through an intervertebral foramen adjacent to vertebrae of same name

Question 7

Nerve

Answer 7

• typically a structure you can see with naked eye (MACROscopic)
• formed from many axonx bundled together in connective tissue wrappings (MICROscopic)

Question 8

Epidural Space

Answer 8

• between dura mater and vertebra
• filed with fat and blod vessles
• most superficial

Question 9

Dura Mater

Answer 9

• dnese connective tissue
• tough mother
• most superficial of maters.

Question 10

Arachnoid mater

Answer 10

• thin spiderweb-like membrane

- deep to dura mater

Question 11

Subarachnoid Space

Answer 11

• space between arachnoid and pia mater

- fluid with cerebrospinal fluid

Question 12

Pia Matter

Answer 12

• thin layer of CT
• delicate mother
• adheres to spinal cord
• deepest

Question 13

Central Canal

Answer 13

• space within gray matter of spinal cord
• lined with ependymal cells
• contains CSF

Question 14

Gray Matter

Answer 14

• inner
• nerve cell bodies unmyelinated axons, glial cells, and interneurons
• 4 subdivisions

Question 15

Anterior (Ventral) Horns

Answer 15

• cell bodies of somatic motor neurons
• innervates skeletal muscle
• more pointed

Question 16

Lateral Horns

Answer 16

• cell bodies of autonomic motor neurons
• prominent only in T1-L2 regions of spinal cord
• innervate cardiac muslce, smooth muscle and glands
• more rounded

Question 17

Posterior (Dorsal) Horns

Answer 17

-interneurons and axons of sensory neurons

Question 18

Gray Commisure

Answer 18

• unmyelinated axons crossing from one side to another

- contains central canal

Question 19

White Matter

Answer 19

• outer
• bundles of unmyelinated axons
• Anterior funiculi
• Lateral funiculi
• Posterior funiculi
• each funiculus contains ascending (sensory) and descending (motor) spinal cord tracts

Question 20

Spinal Cord Tracts

Answer 20

• bundles of axons that run in the white matter of the spinal cord
• 2 main kinds

Question 21

Ascending Tracts

Answer 21

• sensory axons

- travel from body to brain

Question 22

Descending Tracts

Answer 22

-travel from brain to body

Question 23

Naming of Tracts

Answer 23

• based on starting and ending point

- ex: corticospinal tract

Question 24

Spinal Nerves

Answer 24

• each formed from
• anterior (ventral) root: axons of motor neurons
• posterior (dorsal) root: axons of sensory neurons
• posterior (dorsal) root ganglion: attached to posterior root, contains cell bodies of sensory neurons
• when anterior and posterior root unite, they form a spinal nerve
• contains both motor and sensory axons