Spinal Cord

Question 1

How many pairs of spinal nerves are there?

Answer 1

31

Question 2

What root do ALL sensory axons pass in a spinal cord?

Answer 2

Spinal nerve –> Posterior root –> posterior rootlet –> posterior horn of spinal cord

Question 3

How do all motor axons pass into the spinal nerve?

Answer 3

Anterior horn of spinal cord–> anterior rootlet –> anterior root –> spinal nerve

Question 4

What does a spinal nerve pair supply to a body segment?

Answer 4

General sensory to ALL structures
Somatic motor supply to skeletal muscles
Sympathetic supply to skin and smooth muscle

Question 5

Name for an area of skin supplied by sensory innervation from a single spinal nerve?

Answer 5

Dermatome

Question 6

Define Myotome:

Answer 6

Collection of skeletal muscles all supplied by one spinal nerve. Often underlies the dermatome of the nerve but not always.

Question 7

What fibres are contained in the cervical enlargement?

Answer 7

Brachial plexus

from C4-T1

Question 8

What nerves are contained in the lumbar enlargement?

Answer 8

Lumbosacral plexus - responsible for the innervation of the lower limb

Question 9

What is the name of the connective tissue that attaches from the conus medullaris to the dorsal surface of the 1st coccygeal vertebra?

Answer 9

The filum terminale

Question 10

Where does the spinal cord end?

Answer 10

L1-L2

Question 11

The dorsal roots carry afferent/efferent neurons?

Answer 11

Afferent

sensory receptors

Question 12

The ventral roots carry afferent/efferent neurons?

Answer 12

Efferent

motor neurons

Question 13

The dorsal/ventral ramus supplies the muscles and skin of the back region?

Answer 13

Dorsal

Question 14

The dorsal/ventral ramus supplies muscle and skin of the front and limbs?

Answer 14

Ventral

Question 15

Is the dorsal or ventral ramus larger?

Answer 15

Ventral

It supplies a larger region

Question 16

Where is CSF contained?

Answer 16

In the subarachnoid space

Question 17

What separates the dura from the bony wall of the vertebral body?

Answer 17

The epidural space

Question 18

Following its termination at L1/2, what does the spinal cord then become?

Answer 18

The cauda equina

Question 19

What is the name for the small continuous structure of the spinal cord, which follows on from the cerebral ventricular system?

Answer 19

The central canal

Question 20

Is grey or white matter found internally in the spinal cord?

Answer 20

Grey matter

Question 21

Why do the higher levels of the spinal cord contain more white matter?

Answer 21

As the ascending tracts go up they gain more fibres, whereas the opposite is true for descending tracts

Question 22

What do thoracic and upper lumbar segments possess?

Answer 22

Lateral horns

Question 23

What is contained in the lateral horns?

Answer 23

Preganglionic sympathetic neurons

Question 24

What is the name given for the 10 divisions of he spinal cord (at each layer)?

Answer 24

Rexed’s Laminae

Question 25

What sensory spinal tract lies near the superficial tip of the dorsal horn?

Answer 25

Lissauer's Tract | aka dorsolateral fasciculus

Question 26

Define a ganglion:

Answer 26

A group of neuron cell bodies living outwith the CNS | known as a nucleus in the CNS

Question 27

What are the three main blood supplies to the spinal cord?

Answer 27

- 3 major longitudinal arteries - Segmental arteries - Radicular Arteries

Question 28

Where are the longitudinal arteries found?

Answer 28

Run the length of the spinal cord | Originate from the vertebral arteries

Question 29

Where are the segmental arteries found?

Answer 29

Derived from the vertebral, intercostal and lumbar arteries

Question 30

Where are the radicular arteries found

Answer 30

Travel along the dorsal and ventral roots

Question 31

What is the main venous drainage of the spinal cord?

Answer 31

Similar to the arterial | Longitudinal and segmental veins

Question 32

What sensory tract is responsible for fine touch and proprioception?

Answer 32

Dorsal column / medial lemniscus system

Question 33

Where do the fibres cross in the dorsal column / medial lemniscus tract?

Answer 33

Medullar

Question 34

Which sensory spinal tract carried pain, temperature and deep pressure?

Answer 34

Spinothalamic tract

Question 35

Where do the fibres of the spinothalamic tract cross?

Answer 35

Segmentally (i.e. at each level)

Question 36

Where do the fibres of the corticospinal tract decussate?

Answer 36

Pyramids of the medulla | 85%

Question 37

Where do the remaining 15% of fibres in the corticospinal tract decussate?

Answer 37

They don't. | They form the anterior tract instead

Question 38

What tract to the crossed fibres (85%) form?

Answer 38

The lateral corticospinal tract

Question 39

What is the corticospinal tract responsible for?

Answer 39

Fine precise movement | especially of distal limb muscles e.g. digits

Question 40

A CVA of the ____ ______ can result in lack of descending control of the CST

Answer 40

internal capsule

Question 41

Spastic paralysis and hyperflexion of the upper limbs is also referred to as what?

Answer 41

``` Decorticate posturing (caused by a CVA of the internal capsule) ```

Question 42

What extrapyramidal tract is mainly responsible for mediating the head and neck movement in response to visual stimuli?

Answer 42

Tectospinal tract

Question 43

Where does the tectospinal tract mainly input?

Answer 43

The cervical spine

Question 44

Which tract has fibres originating from both the pons and the medulla?

Answer 44

The reticulospinal tract

Question 45

What formation forms a central core of the brainstem?

Answer 45

The reticular formation

Question 46

Fibres originating from the _____ of the reticulospinal tract are responsible for the inhibition of flexor movements and facilitate extensor?

Answer 46

Pons

Question 47

Fibres of the reticulospinal tract which originate in the _____ are responsible for the inhibition of extension and facilitate flexion?

Answer 47

Medulla

Question 48

What tract is responsible for the excitatory input to 'anti-gravity' extensor muscles?

Answer 48

Vestibulospinal tract

Question 49

Where does the vestibulospinal tract receive its input from?

Answer 49

Vestibular apparatus | Cerebellum

Question 50

Is the vestibulospinal tract contra or ipsilateral?

Answer 50

Ipsilateral | The fibres do not cross at any point

Question 51

What spinal tract is thought to play an important role in decerebrate rigidity and extension paraplegia?

Answer 51

Vestibulospinal tract

Question 52

What is decerebrate rigidity and extension paraplegia?

Answer 52

Domination of extensor muscle tone and hyperextended spastic paralysis

Question 53

What syndrome will a lateral hemisection of the spinal cord cause?

Answer 53

Brown-Sequard's Syndrome

Question 54

What are the clinical features of Brown-Sequard's syndrome

Answer 54

Ipsilateral paralysis Ipsilateral hyperreflexia and extensor plantar reflex Ipsilateral loss of vibratory sense and proprioception Contralateral loss of pain and deep temperature sense

Question 55

What is an acute viral infection of the neurons which leads to rapid paralysis and wasting of limb and respiratory muscles?

Answer 55

Poliomyelitis

Question 56

Is the disability in poliomyelitis bilateral or asymmetrical?

Answer 56

Asymmetrical

Question 57

Where does poliomyelitis mainly affect?

Answer 57

Legs

Question 58

What reflex is repsonisble for the maintenance of muscle tone and posture?

Answer 58

Stretch reflex

Question 59

What neurons are responsible for the regulation of the stretch reflex?

Answer 59

Gamma motor neurons

Question 60

What are the two main tracts of the dorsal column tract?

Answer 60

Fasciculus cuneatus | Fasciculus Gracilis

Question 61

Which tract of the dorsal tract has more influence over the lower limb?

Answer 61

Fasciculus gracilis

Question 62

What is Romberg's sign?

Answer 62

High stepping, unsteady gait when eyes are closed

Question 63

What does a positive Romberg's test mean?

Answer 63

Patient has a problem with their dorsal column of the spinal cord Loss of proprioception

Question 64

What disease can selectively damage the spinothalamic tract?

Answer 64

Syringomyelia

Question 65

Where does the rubrospinal tract originate?

Answer 65

The red nucleus of the midbrain

Question 66

What is the main purpose of the rubrospinal tract?

Answer 66

Non pyramidal control of spinal motor activity | Limb flexor muscles