Spinal cord + nerves

Question 1

describe how many vertebra there are in the spine

Answer 1

7 C 
T 12 
5 L 
5 S fused 
3-4 coxxyc

Question 2

what is the function of the spinal cord

Answer 2

reflex centre

conduction pathway

Question 3

what is the start and end of the spinal cord

Answer 3

medulla oblongata (from foramen magnum) 
veterbral levels L1-2 at the conus medullaris

Question 4

which occurs in the spinal cord anatomy after its termination

Answer 4

terminates at conus medullaris which gives of caudal equina

filum terminale - extension of the pia mater to coxccyv
dural sac extension

Question 5

describe the anatomy of the spinal nerves in the spine

Answer 5

31 paired nerves 
8 cervical 
12 T 
5 L 
5 S 
1 C

Question 6

what is the lumbar cistern

Answer 6

subarachnoid space between filum terminale and dural sac which contains CSF

Question 7

what is cervical enlargement

Answer 7

brachial plexus C1-8

Question 8

what is lumbosacral enlargement

Answer 8

L1-S4

Question 9

how do spinal nerves C1 to C7 leave the spinal cord

and C8

Answer 9

above their respected vertebrae ie superior C1 above CI

C8 leaves above T1 as only C7 vertebrae

Question 10

how do spinal nerves from T1 onwards leave the spinal cord

Answer 10

from below their respected vertebrae

Question 11

what are denticulate ligaments

Answer 11

extension of the pia mater which attach the spinal cord laterally

Question 12

as spinal nerves leave the cord what happens to the meninges

Answer 12

leave with the nerve and go on to form epineurium a protective connective tissue

Question 13

what type of space is spinal epidural space

Answer 13

it is real space not potential as it is filled with fat

Question 14

what is the difference in cranial vs spinal dura mater

Answer 14

cranial is double layer

spinal is single layer

Question 15

describe how spinal roots show disparity between their segmental attachments

Answer 15

development - dural sac grows along vertebrae but not spinal cord - VC grows more rapidly and SC regresss upwards leaving lumbar cistern space below

Question 16

describe the process of a lumbar puncture

Answer 16

inserted into lumbar cistern (between L3 and 4)

no damage due to corda equinea

Question 17

why do we have lumbar punctures

Answer 17

test CSF for meningitis or epidural aesthetsia

Question 18

what are the three main arteries of the spinal cord

Answer 18

one anterior artery in the anterior median fissure from the vertebral arteries

two posterior spinal arteries which run in the posterior lateral sulci

Question 19

where do the two posterior spinal arteries originate from

Answer 19

posterior inferior cerebellar artery

Question 20

give examples of supporting spinal arteries

Answer 20

segmental spinal arteries such as
radicular arteries which supply nerve rootlets
deep cervical arteries
lumbar arteries

Question 21

describe the structure venous drainage in the spinal cord

Answer 21

three anterior and three posterior spinal veins

valveless anastamoses

Question 22

what is the process of venous drainage in the spinal cord

Answer 22

drain into internal (epidural) and external (outside VC) vertebral Plexi which in turn drain into systemic segmental veins

Question 23

what two structures does the internal vertebral plexus drain into

Answer 23

dural venous sinuses superiorly and systemic segmental veins

Question 24

describe the disparity of white matter and gray matter in the brain and spinal cord

Answer 24

in brain gray matter on outside

in spinal cord gray matter on the inside

Question 25

what occurs in these sections of the spinal cord:
ventral white commissure 
dorsal horn 
ventral horn 
lateral horn

Answer 25

white matter fibres cross to opposite side of the cord

nuclei of sensory afferents from the body entering through dorsal horn

nuclei of motor efferent from the brain

nuclei of neurones fro autonomic nervous system

Question 26

describe the difference in ventral roots vs dorsal roots

Answer 26

ventral - efferent fibres from the ventral horn and lateral horn (somatic motor from ventral and visceral from lateral)

dorsal afferents fibres to the dorsal horn

Question 27

how does the reflex arc work in the spinal cord

Answer 27

uses an interneuron which connects sensory to related motor which removes need from information to go to the brain for interpretation

Question 28

what happens to white matter as you ascend the spinal cord

Answer 28

increase

Question 29

what is found above segment T6

Answer 29

2 dorsal columns on each side of the midline

gracile fascile medially - carrier’s sensory information from lower limbs

cuneate fasciae laterally - carries sensory information from upper limbs

Question 30

what happens to the cuneate fascicle after T6

Answer 30

disappears

Question 31

how is spinal grey matter organised

Answer 31

into regions known as rexed laminae after rexed 1952

sites of sensory or motor nuclei with specific functions