Chap 17

Question 1

what surrounds and protects that nervous tissue of the spinal cord?

Answer 1

• veterbral column (vertebrae and vertebral ligaments)
• 3 spinal meninges (outermost is dura mater, middle is arachnoid mater and innermost is pia mater)
• cusion of cerebrospinal fluid

Question 2

the outer most meninx (dura mater)

Answer 2

• composed of dense irregular CT
• extends from the level of the foramen magnum to second sacral vertebra
• epidural space (filled with fat and CT that protection)

Question 3

middle meninx (arachnoid mater)

Answer 3

CT with a spiderweb like arrangment of collagen fibers and elastic fibers

Question 4

innermost meninx (pia mater)

Answer 4

• attached to the surface of the spinal cord
• layer of CT that contains collagen fibers and some elastic fibers, blood vessels that provide nutrients and oxygen to the spinal cord
• subarachnoid space

Question 5

what are the 2 enlargements where nerves supply the limb emerge

Answer 5

cervical enlargment (extends from the 4th cerical to the 1st thoracic vertebra)
lumbar enlargment (extends from the ninth to the 12 thoracic vertebra)

Question 6

conus medullaris

Answer 6

in and adult ends at the level of the intervertebral disc between the 1st and 2nd lumbar vertebrae; cone shaped

Question 7

filum terminale

Answer 7

extends inferiorly from the conus medullaris and fuses with the arachnoid mater and dura mater to attach the spinal cord to the coccyx

Question 8

cauda eqina

Answer 8

roots of the spinal nerves emerges from the lower part of the spinal corld to travel inferiorly

Question 9

what are the 2 grooves that divide the spinal cord

Answer 9

anterior median fissure (deep, wide groove on the ventral side)
posterior median sulcus (shallow, narrow groove on the dorsal side)

Question 10

the spinal cord contains what?

Answer 10

a cord of gray matter, shaped like a butterfly when viewed in transverse section that is surrounded by white matter

Question 11

gray matter

Answer 11

consists of cell bodies of neurons, neuroglia, unmyelinated axon, and dendrites

Question 12

white matter

Answer 12

consists of bundles of myelinated axon of motor neurons, interneurons and sensory neurons

Question 13

white matter is subdivided by what?

Answer 13

anterior (ventral)
posterior (dorsal)
lateral

Question 14

tracts

Answer 14

each column contains bundles of nerve axons

• sensory (ascending;transmit nerve impulse upward)
• motor (descending; transmit nerve impulse downward)

Question 15

what are the 31 pairs of spinal nerves

Answer 15

• 8 pairs of cervical nerves; C1-C8
• 12 pairs of thoracic nerve; T1-T12
• 5 pairs of lumbar nerves; L1-L5
• 5 pairs of sacral nerves; S1-S5
• 1 pair of coccygeal nerves; Co1