Spinal Cord Flashcards

1
Q

what is the segmentation of the spinal cord

A
- Cervical – 8 (but 7 cervical vertebrae bones)
o Thoracic – 12
o Lumber – 5
o Sacral – 5
o Coccygeal – 1

total segments- 31

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Each segment gives rise to a _____ of spinal nerves

A

pair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the lower limit of the spinal cord in adults and infants

A

New born infants- L3/L4 vertebrae

Adults- L1/L2 border

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

describe the passing of spinal nerves in relation to their vertebrae

A

C1-7 pass through the intervertebral foramen above their vertebrae
C8 – Coc1 pass through the intervertebral foramen below their vertebrae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the upper limit of the spinal cord

A

at junction with the medulla oblongota of the brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what embryological sturcure is the spinal cord formed by

A

Neural Tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how is neural tube formed

A

develops from a flat plate of cells called

the neuro-ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how is a tube of neuroectoderm formed

A

Edges of plate rise up and meet each other in midline- forming a central canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

WHat is the central canal of the neuroectoderm tube surrounded by

A

nervous tissue (grey and white matter)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The neural tube has two different plates of cells. what does the alar plate form

A

Dorsal grey matter (sensory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the basal plate form

A

Ventral grey matter (motor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how does spina bifida occurs

A

due to the failure of neural tube closure in the caudal area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the types of spina bifida severities

A
  1. Occulta- least severe with no outwards sign
  2. Lipo-meningocele- spinal cord attached to fatty growth- can be outward signs
  3. Meningocele
  4. Myelomeningocele
    Both 3 and 4 can be severely affected by paralysis, loss of sensation and other defects below level of deformity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does the grey matter of the spinal cord include

A

Dorsal Horn
Intermediate Horn
Ventral Horn

Transverse section- grey matter is towards the central part of the spinal cord
(see pics)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does the white matter of the spinal cord include

A

Dorsal Funiculus
Lateral Funiculus
Ventral Funiculus

Transverse section- white matter is towards the peripheral part of the spinal cord
(see pics)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what occurs in the grey matter areas

A

Dorsal Horn- sensory function
Intermediate Horn- Autonomic function
Ventral Horn- Motor function

17
Q

what occurs in the white matter areas

A

Dorsal Funiculus- involved in ascending pathway
Lateral Funiculus- contains the lateral corticospinal and rubrospinal tracts
Ventral Funiculus- involved in pain and temperature pathways

18
Q

whats the difference between the sizes of the grey matter in the spinal cord segmentations and why

A

Cervical and lumber regions have a larger ventral grey matter region compared to sacral and thoracic because they supply the musculature of the limbs and require finer control of movements.

19
Q

describe the spinal cord segmental innervation

A

Cervical- upper limb
Thoracic- Thorax
Lumbar- lower limb
Sacral- genital area

20
Q

Describe the dura mater layer of the meninges in the spinal cord

A
  • Outer meningeal layer – thick inelastic membrane
  • Fuses with the endosteum of the cranium at the foramen magnum (opening that connects spinal cord to brain)
  • Space between dura mater and vertebral endosteum is the epidural space (epidural space has fat and blood vessels)
21
Q

What is the difference between spinal cord and brain dura mater

A
Brain:
Dura has 2 layers:
- Outer periosteal layer 
- Inner meningeal layer 
No epidural space between periosteal layer and the cranium- epidural space only exists when pathology occurs e.g. epidural haematoma (blood collects in the space)

Spinal Cord:
Dura has 1 layer: outer meningeal layer
Epidural space exists between vertebrae and meningeal layer even without pathology. Normal epidural space contains fat and blood vessels

22
Q

Describe the arachnoid mater layer of the meninges in the spinal cord

A
  • Middle meningeal layer – thin fibrous membrane
  • Space between arachnoid mater and pia mater is the subarachnoid space which contains CSF
  • Contains trabeculae which go to the pia mater
23
Q

Describe the pia mater layer of the meninges in the spinal cord

A
  • Innermost meningeal layer – unicellular membrane
    surrounding the spinal cord
  • Quite vascularised
  • Pair of denticulate ligaments (one each side) with 21
    attachments laterally to the arachnoid mater
  • Separated from the spinal cord by the subpial space
24
Q

what is the CSF and what are its functions

A

A filtrate of blood

Affords mechanical and immunological protection to the brain and spinal cord

25
Q

Describe the production and reabsorbtion of the CSF

A

Made in the choroid plexus within the ventricular system of the brain
Produced around 500 ml each day
About 140ml circulates throughout the subarachnoid space
Reabsorbed into the venous drainage system of the head

26
Q

Describe the venous drainage of the spinal cord

A

3 ANTERIOR AND 3 POSTERIOR VEINS WHICH FORM THE:

Posterior and anterior internal and external venous plexus

27
Q

where is the venous drainage found in

A

Venous drainage found in the epidural space

28
Q

Why is the Batson venous plexus a major route for metastasis

A

The Batson venous plexus is major route for metastasis of cancer from deep pelvic regions since they are valveless

29
Q

what is the arterial supply of the spinal cord

A

Supplied by:
2 posterior spinal arteries:
- Forms from vertebral artery or posterior-inferior cerebellar artery
- Anastomose

1 anterior spinal artery:
- Forms from branches of vertebral artery – arises from
brachiocephalic artery
-Lies in anterior median fissure

30
Q

what does artery of adamkiewicz supply and what does it arise from

A

supplies lower 1/3 of the spinal cord

typically arises from left posterior intercostal artery

31
Q

what is the clinical signifcance of the artery of adamkiewicz

A

loss of urinary and/or faecal continence

impaired motor function of legs/ spasticity

32
Q

what is the conus medullaris

A

tapered most inferior part of the spinal cord near L1/2

33
Q

what is the cauda equina

A

is the bundle of spinal nerve and spinal nerve rootlets from L1/2-L5 which arises from the conus medullaris

34
Q

what is the filum terminale

A

a strand of fibrous connective tissue which anchors the conus medullaris to the coccyx

35
Q

what is the lumbar cistern

A

subarachnoid space in the lower lumbar spinal canal
Cistern is an enlargement of the subarachnoid
space distal to the conus medullaris

36
Q

what is the lumbar cistern site of and at what vertebral level does this occur

A

site for epidural injections and lumbar punctures

L3/4 or L4/5 vertebral level

37
Q

what are the uses of epidural and lumbar puncture

A

Epidural Injections use:
- Administration of anaesthetics

Lumbar punctures use:
o Diagnostic:
- Withdraw CSF
- Measure CSF
- Pressure

o Therapeutic:
- Administration route for antibiotics or chemotherapy

38
Q

what level is iliac crest at?

A

L4