spinal cord and spinal nerves

Question 1

spinal cord- length and segments

Answer 1

extends from foramen magnum to L2, made of cervical, thoracic, lumbar, sacral

Question 2

how many pairs of spinal nerves are there

Answer 2

31

Question 3

cervical vs lumbar enlargements

Answer 3

cervical- supplies upper limbs
lumbar- supplies lower limbs

Question 4

conus medullaris

Answer 4

tapered inferior end of spinal cord

Question 5

cauda equina

Answer 5

origins of spinal nerves extending inferiorly from lumbosacral enlargement and conus medullaris

Question 6

meninges

Answer 6

connective tissue surrounding the spinal cord and brain

Question 7

dura mater

Answer 7

outermost, thickest membrane of spinal cord, continuous with brain dura mater

Question 8

arachnoid mater

Answer 8

thin, whisky middle membrane of spinal cord

Question 9

pia mater

Answer 9

innermost membrane of spinal cord, bound tightly to surface of brain, forms film terminal

Question 10

filum terminale

Answer 10

anchors spinal cord to coccyx

Question 11

denticulate ligaments

Answer 11

attach spinal cord to dura mater

Question 12

epidural space

Answer 12

between bone periosteum and dura mater, contains roots of spinal nerves, blood vessels

Question 13

subdural space

Answer 13

between the dura mater and arachnoid mater, contains a small amount of serous fluid

Question 14

subarachnoid space

Answer 14

between arachnoid and Pia mater, helps nourish NS, contains CS fluid and blood vessels

Question 15

anterior median fissure and posterior median sulcus

Answer 15

deep clefts separating the spinal cord into right and left halves

Question 16

white vs grey matter location

Answer 16

white: peripherally, grey: centrally

Question 17

what are the 3 columns of white matter

Answer 17

ventral, dorsal, lateral

Question 18

what do white matter tracts do

Answer 18

carry info to or from the CNS

Question 18

what are the 3 gray matter horns

Answer 18

posterior (dorsal), anterior (ventral) and lateral (ANS)

Question 19

commissure

Answer 19

a connection btwn the right and left halves of the spinal cord

Question 20

white vs gray commissures

Answer 20

gray: contains central canal, connects gray spinal cord.
white: connects white spinal cord

Question 21

what do the spinal rootlets form

Answer 21

roots: dorsal and ventral

Question 21

how do spinal nerves arise

Answer 21

as rootlets

Question 22

dorsal vs ventral root

Answer 22

dorsal: has a ganglion, sensory/afferent
ventral: motor axon, efferent

Question 23

spinal nerve

Answer 23

where the dorsal and ventral roots converge, called a mixed nerve bc it contains both sensory and motor axons

Question 24

dorsal root ganglion

Answer 24

collection of cell bodies of sensory neurons from the periphery forming dorsal roots

Question 25

ventral root

Answer 25

contains axons of motor neurons, has cell bodies located in anterior or lateral horns

Question 26

lateral vs anterior gray matter horns

Answer 26

anterior: somatic motor neurons lateral: autonomic motor neurons

Question 27

pairs of spinal nerves per section

Answer 27

8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal

Question 28

dorsal ramus of spinal nerves

Answer 28

innervates deep muscles of the trunk responsible for movements of the vertebral column and skin near midline of back

Question 29

ventral ramus of spinal nerves

Answer 29

forms intercostal nerves in the thoracic region, or form 5 plexuses

Question 30

5 plexuses of the spinal nerve ventral rami

Answer 30

1. C1-C4= cervical 2. C5-T1= Brachial 3. L1-L4=lumbar 4. L4-S4= sacral 5. S5 and Co= coccygeal

Question 31

cervical plexus

Answer 31

C1- C4, innervates superficial neck muscles, skin of neck and posterior head

Question 32

brachial plexus

Answer 32

C5-T1, 5 ventral rami that form 3 trunks that separate to 6 branches: the axillary, radial, musculocutaneous, ulnar, median

Question 33

Axillary branch of brachial plexus

Answer 33

innervates the deltoid, tires minor, sensory info for inferior lateral shoulder

Question 34

radial branch of brachial plexus

Answer 34

innervates all extensor muscles of the upper limb, supinator, brachioradialis, sensory info to posterior upper limb, lateral 2/3 of dorsal hand

Question 35

musculocutaneous branch of brachial plexus

Answer 35

innervates anterior muscles of the arm, flexor muscles, sensory info to lateral forearm

Question 35

median nerve branch of brachial plexus

Answer 35

innervates all flexor muscles of the forearm except 1, wrist flexors, thumb muscles, sensory info to lateral 2/3 of palm

Question 36

ulnar nerve branch of brachial plexus

Answer 36

innervates intrinsic hand muscles, sensory to medial 1/3 of hand (little finger and medial half ring finger)

Question 37

lumbar and sacral plexus

Answer 37

lumbar = L1-L4, sacral= L4-S4. house obturator, femoral, tibial, common fibular (peroneal) nerves

Question 38

obturator nerve of lumbosacral plexus

Answer 38

innervates thigh adductors, sensory info to medial side of thigh

Question 39

tibial nerve of lumbosacral plexus

Answer 39

innervates posterior thigh and leg muscles, branches into others to supply plantar, no direct sensory info but branches into foot supply

Question 40

femoral nerve of lumbosacral plexus

Answer 40

innervates hip flexors and knee extenders (iliopsoas, sartorius, quads), sensory info to anterior and lateral thigh, medial leg and foot

Question 41

common fibular (peroneal) nerve of lumbosacral plexus

Answer 41

innervates biceps femoris, branches into other nerves

Question 42

coccygeal plexus

Answer 42

s5- coccygeal nerve, innervates pelvic floor, sensory input to skin over coccyx and around anus