Spinal cord anatomical overview

Question 1

how many cervical segments of spine?

Answer 1

8

Question 2

how many lumbar and sacral segments of spine?

Answer 2

5 each

Question 3

Extenging from each section of the spine are:
8 ??? cervical spinal nerves, 12 pairs of thoracic spinal nerves, 5 pairs of lumber spinal nerves and 5 pairs of sacral spinal nerves

Answer 3

Pais of

Question 4

TRUE or FALSE: Spinal nerves C1-C7 exit above their corresponding vertebral body, however from C8 spinal nerve onwards the spinal nerves exit below their corresponding vertebra

Answer 4

TRUE

Question 5

The spinal cord ends at about vertebral level L1/2 as a cone shape called ???

Answer 5

conus medullari

Question 6

In infants, the spinal cord reaches full adult length before the ???

Answer 6

vertebral canal

Question 7

At what fetal stage do the vertebral canal and the spinal cord grow at the same rate? After this the body and the verterbral canal grow at a faster rate than the cord. At the time of birth the spinal cord ends at the third lumbar vertebrae.

Answer 7

third month

Question 8

The spinal cord has 2 enlargements known as :
- ???
- Lumber

Answer 8

Cervical

Question 9

Why does the spinal cord have 2 enlargements?

Answer 9

because extra neurons are needed at these levels to allow for innervation of the upper and lower limbs.

Question 10

A dermatome is a ??? and an area they receive sensory innervation from

Answer 10

pair of spinal nerves

Question 11

What kind of information do dorsal roots carry, motor or sensory?

Answer 11

sensory

Question 12

Dermatomes often overlap so that injury to an individual dorsal root does not lead to ???

Answer 12

complete loss of sensation in the relevant skin region

Question 13

TRUE or FALSE: the overlap of dermatomes is less extensive for touch pressure and vibration than for pain and temperature.

Answer 13

FALSE: more extensive for touch and pressure

Question 14

Why does testing for pain sensation provide a more accurate assessment of a segmental nerve injury than testing for responses to touch, pressure or vibration?

Answer 14

because the overlap of dermatomes is more extensive for touch and pressure

Question 15

If 1 dorsal root is cut, the corresponding dermatome on that side of the body does not lose all sensation. WHY?

Answer 15

The residual somatic sensation exists perhaps because the adjacent dorsal roots innervate overlapping areas

Question 16

How many dorsal roots must be cut to lose all sensation in one dermatome?

Answer 16

3 dorsal roots

Question 17

The dura mater surrounding the spinal cord consists of only a single layer. This is the ??? layer

Answer 17

meningeal layer. It has no periosteal layer, only the brain does

Question 18

The epidural space is a space between the meningeal dura and the vertebrae created by the lack of a ??? - it is filled with fat and vessels

Answer 18

The lack of a periosteal dural layer creates a ‘space’ between the meningeal dura and the vertebrae.

Question 19

The spinal ??? provides an avenue to inject anaesthesia into this area to anaesthetise the nerve roots,i.e. epidural anaesthesia

Answer 19

epidural space

Question 20

??? is one of the subarachnoid cisterns

Answer 20

lumber cistern

Question 21

What is is an enlarged region of the subarachnoid space that sits below the conus medullaris and contains the floating cauda equina?

Answer 21

the lumber cistern

Question 22

The lumber cistern and epidural space are between different layers. The epidural space runs along the full length of the cord and sits between the dura mater and the ???

Answer 22

vertebrae.

Question 23

Why is the lumber cistern not found at higher levels of the spinal cord?

Answer 23

because it sits below the conus medullaris between the pia mater and arachnoid mater in subarachnoid space

Question 24

The lumber cistern is present below the conus medullaris which corresponds to the vertebral levels ???

Answer 24

L2/3

Question 25

lumber cistern can be used as a diagnostic test for ??? without risk of damaging spinal tissue because ???

Answer 25

meningitis because no spinal cord is present at this level, only cauda equina floating in the CSF

Question 26

lumber cistern can be used for imaging i.e a myelogram which is ??? This allows visualisation of cord integrity and identification of injury, cysts, impinging discs or other structural anomalies.

Answer 26

is an X-ray that is taken of the spine after a dye has been injected into the CSF which would then travel around the subarachnoid space around the cord.

Question 27

Anesthesia can be injected into this space.

Answer 27

lumber cistern

Question 28

The spinal cord is anchored to the ??? bone by meningeal extensions called the Film Terminale

Answer 28

coccyx

Question 29

the filum terminale is made of two parts. part 1 is the ??? and is an extension of pia mater from the bottom of the cord that attached to a piece of dura mater called the filum terminale externum.

Answer 29

filum terminale interum

Question 30

The filum terminale externum OR interum (?) is made up of dura mater and attached to the coccyx bone

Answer 30

externum

Question 31

which type of matter is primarily made up of axons? white or grey?

Answer 31

white

Question 31

the dorsal or ventral horn of grey matter consists of cell bodies that process sensory information

Answer 31

dorsal horn of grey matter

Question 32

which type of matter is primarily made up of cell bodies of interneurons and some efferent neurons, white or grey?

Answer 32

Grey matter

Question 32

The ventral horn of grey matter contains cell bodies that contain motor or sensory information?

Answer 32

motor information

Question 33

Extending from the dorsal horn is the ??? which carries ??? information from the periphery into the spinal cord.

Answer 33

dorsal root carries sensory info

Question 33

at which spinal levels does grey matter also contain a lateral hornm holding pre-ganglionic sympathetic cell bodies?

Answer 33

At the spinal levels of T1-L2

Question 34

Extending from the ventral horn is the ??? which carries ??? information to muscles and glands

Answer 34

ventral root, carrying motor information

Question 35

what combines to make the psinal nerve, protruding from the grey matter?

Answer 35

dorsal and ventral roots of the dorsal and ventral horns of grey matter

Question 36

Motor neurons in the ventral horn are organised in a ???

Answer 36

somatotopic organisation

Question 37

Somatotopic organisation: - Motor neurons controlling more proximal/axial musculature are located more ??? in the ventral horn - Motor neurons controlling more distal musculature are located more ??? in the ventral horn

Answer 37

medially laterally

Question 38

The white matter is divided into zones called Funiculi & ???

Answer 38

Fasciculi

Question 39

Dorsal or Posterior Funiculus (Dorsal columns) has two smaller subdivisions, the ??? and Cuneate fasciculus

Answer 39

Gracile

Question 40

the Gracile or Cuneate fasciculus (?) carries sensory information regarding lower limbs and is present at EVERY level of the cord

Answer 40

Gracile fasciculus

Question 41

Which fasciculus, gracile or cuneate, carries sensory information regarding upper limbs and is present ONLY at cervical and upper thoracic levels.

Answer 41

cuneate fasciculus

Question 42

Apart from the gracile and cuneate fasciculi, what other white matter areas are there?

Answer 42

Lateral Funiculus (Lateral columns) Ventral or Anterior Funiculus (Ventral columns)

Question 43

TRUE or FALSE: The size of funiculi change with the level of the cord

Answer 43

TRUE. Cervical cord has large funiculi which get progressively smaller as you descend the cord.

Question 44

Why does the cervical region of the spinal cord have the largest amount of white matter?

Answer 44

Because the funiculi carry axons that travel up the cord = everything entering at sacral and lumber levels has to pass through cervical level to reach the brain. Likewise everything traveling down to the lumber/sacral levels has to travel through the cervical level to reach these lower levels.

Question 45

??? funiculus carries both motor and sensory tracts: - Motor tracts: corticospinal and rubrospinal tracts - Sensory tracts: spinothalamic & spinocerebellar tracts

Answer 45

Lateral funiculus

Question 46

??? funiculus carries both motor and sensory tracts: - Motor: Anterior corticospinal, reticulospinal, vestibulospinal and tectospinal tracts - Sensory tract: Spinothalamic tract

Answer 46

Ventral (anterior)

Question 47

These are characteristics for which part of spinal cord? - Presence of ??? enlargement - Large amount of white matter - Separation of dorsal funiculus into gracile and cuneate fascuculi

Answer 47

Cervical

Question 48

These are characteristics for which part of spinal cord? - Small amount of grey matter - Upper shows separation of dorsal funiculus into gracile + cuneate. Mid-lower shows gracile only. - Presence of lateral horn (containing pre-ganglionic sympathetic neurons)

Answer 48

Thoracic

Question 49

These are characteristics for which part of spinal cord? - Large dorsal and ventral horns - No separation of the dorsal column, only gracile fasciculus is present at this level.

Answer 49

Lumbar

Question 50

These are characteristics for which part of spinal cord? - No separation of dorsal funiculus - Little white matter - Contains pre-ganglionic parasympathetic neurons

Answer 50

Sacral

Question 51

Blood supply to the spinal cord is largely from how many arteries?

Answer 51

3 arteries

Question 52

1 x anterior spinal artery supplies the anterior ??? of the cord (including the ventral horns, ventral and lateral funiculus) 2 x posterior spinal arteries which supply the posterior ??? of the cord (including the dorsal horn and dorsal funiculus)

Answer 52

2/3 1/3