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Flashcards in W2 Practical Deck (58)
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1
Q

What structures form the anterior and posterior walls of the vertebral canal?

A
  • anterior wall (floor): vertebral bodies, intervertebral discs and posterior longitudinal ligament
  • posterior wall (roof): laminae (+ inferior articular processes) and ligamenta flava (connects laminae)
2
Q

Where is the epidural space? What is found in this space and what is its function?

A
  • epidural space - surrounds dural (thecal) sac
  • contents
    • internal vertebral venous plexus (and epidural fat): cushion to protect the dural sac and its contents (incl. spinal cord)
    • epidural fat: extends into intervertebral foramen + intervertebral veins → cushion emerging spinal nerves
    • recurrent meningeal (sinuvertebral) nerves: supplies posterior longitudinal ligament, adjacent periosteum of vertebral body, outer part of annulus fibrosus, dura mater and blood vessels
3
Q

What are the name of the 3 layers of meninges? Which is outermost and strongest?

A
  • dura mater, arachnoid mater and pia mater
  • outermost and strongest: dura mater
4
Q

Between which two layers of meninges is CSF located? What is the name of this CSF-filled space?

A
  • between the arachnoid mater and the pia mater
  • the sub-arachnoid space
5
Q

conus medullaris

A

caudal tip of the spinal cord

6
Q

How much of the vertebral column does an adult spinal cord occupy?

A

The upper two thirds

7
Q

filum terminale

A

pia mater that continues in the vertebral canal like a long thing string that anchors the spinal cord inferiorly

8
Q

At which level is the conus medullaris typically located in an adult?

A

Between L1 and L2

9
Q

cauda equina

A
  • name for all nerve roots inferior to the spinal cord, but still in the vertebral canal
  • contained in dural sac ∴ bathed in CSF
10
Q

columns (in the spinal cord)

A

regions of spinal cord white matter with ascending and descending axons

11
Q

Which constituent of white matter makes it white in colour?

A

The myelin surrounding the axons

12
Q

spinal cord segment

A
  • gives rise to pair of spinal nerve roots
  • innervates exactly one dermatome and myotome on either side of the body
13
Q

Label:

dorsal horn, ventral horn, central canal, ventral and dorsal nerve roots

A
14
Q

Cell bodies in ventral/anterior horns

A

lower motor neuron cell bodies - sends axons through ventral nerve roots to control skeletal muscle

15
Q

Where are the thickenings of the spinal cord? Why do these enlargements exist?

A
  • lumbo-sacral and cervical enlargements
  • Increased function required, also they are usually the innervation for muscles in the limbs which require more control
16
Q

tract

A

bundle of axons in the CNS that serve a particular function

note: a white matter colums usually contains multiple tracts (tracts are hard to distinguish by simple inspection)

17
Q

What can a functional pathway be made of?

A

series of tracts, combined with peripheral nerves

18
Q

anterior, posterior, superior and inferior boundaries of the intervertebral foramina

A
  • anterior: body of vertebra, intervertebral disc
  • posterior: zygopophyseal joints and articular processes
  • superior: inferior vertebral notch of pedicle of the superior vertibrae
  • inferior: superior vertebral notch of pedicle of the inferior vertibrae
19
Q

contents of the intervertebral foramen

A
  • anterior and posterior nerve roots (with dorsal root ganglia)
  • dural sleeve (around nerve roots)
  • recurrent meningeal nerve
  • radicular artery (to nerve roots)
  • intervertebral (communicating) veins
  • connective tissue (continuous with epidural fat)
20
Q

Which spinal nerves come out above the vertebra of the same name?

A

C1 to C7

21
Q

Which spinal nerves come out below the vertebra of the same name?

A

thoracic, lumbar and kinda sacral and coccygeal

22
Q

Which spinal nerve has no named vertebra to correspond with?

A

C8

23
Q

identify:

  • dorsal horn, dorsal root, dorsal root ganglion
  • ventral horn, ventral root
  • spinal nerve proper, posterior ramus and anterior ramus
A
24
Q

Which nerve root is motor and which is sensory?

A
  • motor = ventral
  • sensory = dorsal
25
Q

What does a dorsal root ganglion contain? Where are DRGs located in relation to vertebrae?

A
  • cell bodies of sensory neurons
  • dorsolaterally to vertebral body (in intervertebral foramen)
26
Q

What type of fibres does the spinal nerve proper contain?

A

Mixed sensory and motor nerves

27
Q

What type of fibres are within the dorsal and ventral rami?

A

mixed sensory and motor nerve fibres

28
Q

What is the recurrent meningeal nerve? What is its function?

A
  • nerve that reroutes from emerging spinal nerve (is mixed)
  • supplies posterior longitudinal ligament, adjacent periosteum of vertebra, outer part of annulus fibrosus, dura mater (and blood vessels)
29
Q

Draw: roots, trunks, anterior and posterior division, cords and branches of the brachial plexus

A
30
Q

Where is the C2 dermatome?

A

back of head and neck closest to the jaw

31
Q

What are the dermatomes for lower limb sensation?

A

L1-S2 (S3 and S4 are more arse)

32
Q

dermatome

A

area of skin mainly supplied by a single spinal nerve

33
Q

myotome

A

group of muscles that a single spinal nerve innervates

34
Q

Can you demonstrate the movement of the T1 myotome? Compare this to the T1 dermatome.

A
  • T1 myotome: finger abduction
  • T1 dermatome: ventral area of forearm (not the hand at all)
35
Q

Which spinal cord segments innervate the upper limb muscles? Which innervate the lower limb muscles?

A
  • upper limb: C5 to T1 (brachial plexus)
  • lower limb: T12 to S4 (lumber and sacral plexus)
36
Q

(Draw a diagram to demonstrate or) describe the pathway of a LMN leaving the spinal cord to supply the muscle of the forearm.

A
  • possible originating spinal segment: any from C5 to T1
  • nerve root: ventral
  • rami: ventral (anterior)
  • peripheral nerve: most likely median
37
Q

Explain in general terms the motor and sensory deficits that would be created by damage to a peripheral nerve

A
  • complete loss of motor and sensory nerve to muscles and areas innervated by the peripheral nerve
38
Q

Explain in general terms the motor and sensory deficits that would be created by damage to a spinal nerve

A
  • may not be prominent, especially in nerves involved in nerve plexus
  • dermatome innervation may be affected, so sensory deficit may be obvious in areas dedicated to a specific dermatome
39
Q

identify: cerebral hemisphere, cerebellum and brainstem

Which of these join directly to the cervical spinal cord?

A
  • brainstem joins directly to the cervical spinal cord
40
Q

identify: midbrain, pons and medulla

A
41
Q

cerebral cortex

A

continuous sheet of grey matter on the outer layer of each cerebral hemisphere

42
Q

identify lobes of the brain and also their boundaries

A

missing:

  • lateral fissure between frontal + parietal lobes and temporal lobe
  • longitudinal fissure between the two hemispheres of the brain
43
Q

precentral gyrus

A
  • primary motor cortex
  • from medial to lateral: lower limb, upper limb and then face
44
Q

postcentral gyrus

A

primary sensory cortex

45
Q

corticospinal tract

A

important upper motor neuron route that allows key neurons (UMN) in the primary motor cortex to control lower motor neurons in appropriate spinal cord segments

46
Q

At what level of the CNS does the corticospinal tract decussate?

A
  • if lateral corticospinal tract (the majority): decussation below the medullary pyramids
  • if anterior corticospinal tract, do not decussate until they synapse with LMN
47
Q

stroke

A
  • focal lesion of in CNS
  • almost always unilateral
48
Q

hemiparesis

A
  • aka hemiplegia, weakness of one side
  • hemiparetic gait - characteristic abnormality
  • if lesion is before decussation → affects contralateral limbs
49
Q

If the disability shown here is due to a focal brain lesion, on which side is the lesion?

A

right side of the brain

50
Q

cerebellum

A
  • second brain: has own cortex and deep nuclei
  • operations are all below consciousness of cerebrum
  • compares info from brain and spinal cord → coordinate smooth movement
  • damage = impaired coordination of limb movements and unsteady gait ataxia (not weakness though)
51
Q

basal ganglia

A
  • group of nuclei surrounding the thalamus
  • important for timing and programming of movements → control balance between action and stillness
  • does not receive direct sensory feedback
52
Q

How does one palpate for L2 spinal segment?

A
  1. palpate for iliac crest
  2. apex of iliac crest lines up (usually) with L4 spinal segment (can feel the spinous process)
  3. count two up
53
Q

lumbar cistern

A

subarachnoid space for lumbar region and cauda equina

54
Q

How does one tell the difference between the anterior median fissure and the posterior median sulcus?

A

anterior median fissure is deeper, also sometimes the posterior median sulcus is actually hard to define

55
Q

lumbar plexus roots and sciatic nerve roots

A
  • lumbar plexus: T12 - L5
  • sciatic nerve roots: L4 - S3
56
Q

What is the clinical significance of the brainstem?

A
  • primary respiratory centre
  • many sensory centres reside/pass here
  • pressing against brainstem → lack of respiratory activity → DEATH
57
Q

What is the clinical significance of the honumculus?

A

stroke signs align with the largest areas of the homunculus

58
Q

Layers from skin to brain

A
  • SCALP
    • Skin
    • Connective tissue (blood vessels, sensory neurons etc.)
    • Aponeurosis
    • Loose connective tissue
    • Periosteum
  • Skull (Bone)
  • three meningeal layers