2.4 Spinal Nerves

Question 1

What is a nerve?

Answer 1

consists of hundreds of thousands of axons wrapped in connective tissue

Question 2

Where are nerves found?

Answer 2

PNS

Question 3

What are ganglia?

Answer 3

collections of cell bodies in the PNS

Question 4

How many pairs of spinal nerves are there?

Answer 4

31 pairs

Question 5

Where do spinal nerves originate?

Answer 5

spinal cord

Question 6

How many pairs of cervical nerves are there?

Answer 6

eight

Question 7

How many pairs of thoracic nerves are there?

Answer 7

twelve

Question 8

How many pairs of lumbar nerves are there?

Answer 8

five

Question 9

How many pairs of sacral nerves are there?

Answer 9

five

Question 10

How many pairs of coccygeal nerves are there?

Answer 10

one

Question 11

How do spinal nerves leave the spinal cord?

Answer 11

roots

Question 12

What does the dorsal root contain?

Answer 12

axons of afferent sensory neuronswhich conduct impulses to the cord

Question 13

What does the ventral root contain?

Answer 13

axons of efferent motor neurons which conduct impulses away from the cord

Question 14

Where do the ventral and dorsal roots join

Answer 14

just before the spinal nerve leaves the vertebral column

Question 15

What do spinal nerves immediately divide into once they leave the vertebral column?

Answer 15

dorsal ramus
ventral ramus

Question 16

What is the dorsal ramus?

Answer 16

contains nerves that serve the dorsal portions of the trunk carrying visceral motor, somatic motor, and sensory information to and from the skin and muscles of the back

Question 17

What is the ventral ramus?

Answer 17

contains nerves that serve the remaining ventral parts of the trunk and the upper and lower limbs carrying visceral motor, somatic motor, and sensory information to and from the body surface, body wall, and limbs

Question 18

What is a nerve plexus?

Answer 18

network of interconnecting nerves

Question 19

What do nerves that emerge from a plexus contain?

Answer 19

fibers from various spinal nerves which are carried together to some target location

Question 20

What are the major plexi?

Answer 20

cervical
brachial
lumbar
sacral