2: Spinal Chord Function and Dysfunction

Question 1

How many pairs of spinal nerves are there?

How are they classified?

Answer 1

31 Pairs

• 8 Cervical
• 12 Thoracic
• 5 Sacral
• 5 Lumbar
• 1 Coccyngeal

Question 2

How do nerves leave the vertebra colum?

Answer 2

•Nerves leave the vertebral column through intervertebral foramina

Question 3

Where are normal enlargements of the spinal chord found?

Why?

Answer 3

Enlargements for innervation of the limbs:

• Cervical (C3-T1)
• Lumbar (L1-S3)

Question 4

How do spinal levels and vertebra levels relate to one another?

Answer 4

Discrepancy between spinal levels and vertebral levels

• Vertebra level: Level of the vertebra the spinal nerve emerges from the vertebra colum
• Spinal level: Level where the spinal segment has its origin
  
  • –> Vertebra level can be much further down than spinal levels, especially at lumber + sacral region

Question 5

How is the organisation of the meningeines in the spinal chord different from the one in the Brain?

Answer 5

In spinal chord

• ther is space between the Dura Mater and the Bone

–> has a physiological epidural space (relevant for e.g. anestesia)

Question 6

What is the difference between a root and a ramus?

Answer 6

Root:

• e.g. dorsal root + ventral root: carry either sensory or motor information to/from spinal chord

Ramus:

• Splitting of mixed spinal nerve that either supplies the back (posterior ramus) or the front (anterior ramus)

Question 7

What are the neurological termes used for

• Anterior
• Posterior
• Superior
• Inferior

Answer 7

Anterior= Ventral

Posterior = Dorsal

Superior = Rostal

Inferior = Caudal

Question 8

Answer 8

Question 9

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

Answer 14

Question 15

Answer 15

Question 16

Name + Function

Answer 16

Posterior Colum:

• Sensory (touch, pain etc.) from ipsilateral limbs

Question 17

Name + Function

Answer 17

• Pain and Temperature from contralateral side to body
• Motor to ipsilateral anterior spinal horn
• Proprioception (Gefühl von Selbstbewegung und Körperhaltung) from limbs to cerebellum

Question 18

Name + Function

Answer 18

Motor to ipsi and contralateral anterior horn

Question 19

What does the Faciculus gracilis spinal tract controll? Where is it Situatied?

Answer 19

It is located in posterior colum:

• Sensory (touch, vibration , proprioception) from ipsilateral lower limb)

Question 20

Answer 20

Question 21

What is the Faciculus Cuneatus?

Where is it situated?

Answer 21

Posterior Colum

• Sentory (touch, vibration etc.) from ipsilateral upper limb

Question 22

Where is the spinocerebellar tract located?

What is its function?

Answer 22

Located in the lateral column:

• conveys proprioception (Gefühl von Selbstbewegung und Körperhaltung) from limbs to cerebellum

Question 23

Answer 23

Question 24

Answer 24

Question 25

Answer 25

Question 26

What is the function of the Lateral Corticospinal tract? Where is it situated?

Answer 26

* Located at latereal colum * Conveys motor infromation to ipsilateral anterior horn (mostly for limb musculature)

Question 27

What it hte function of the Spinothalamic tract? Where is is located?

Answer 27

Conveys Pain and Temperarture from contralateral side of body (crosses when entering) * Located in lateral colum (around anterior horn)

Question 28

Answer 28

Question 29

Answer 29

Question 30

What is the function of the anterior coticospinal tract? Where is it located?

Answer 30

* It is located in the anterior colum * Motor to ipsi and contralateral anterior horn (mostly axial musculature) * Axial Musculature= muscles that move head, neck, spine and ribcage

Question 31

What is the anterior white commisure?

Answer 31

Part of spinal chord where * pain and temperature fibres * Anteriorcorticospinal tract fibres cross

Question 32

What does decussation mean?

Answer 32

The crossing over of nerve fibres

Question 33

Explain the route and function of the dorsam colum pathways

Answer 33

* Fasciculus gracilic and Fasciculus Cuneatus * Discriminative touch, vibration, proprioception * 2nd. neurone crosses over at Medulla

Question 34

Compare the two main sensory pathways (Dorsal colum pathway and spinothalamic tract) in regard to their route to the brain.

Answer 34

Spinothalamic tract (pain, temperature) * synapses earlier, 2nd. neuron crosses sides when entering (or 2 vertebra up or down the neuron takes via the **Lissauer tract**) Dorsal Colum pathways * cross over in Medulla (synapse in dorsal column nuclei)

Question 35

Explain the function and route of the corticospinal tract

Answer 35

Corticospinal tract * Main tract for voluntary movment of limbs and trunk * Two motor neuron * Devides in the **Lateral corticospinal tract** * major root (about 85%) * Decussion in the **medulla oblangata** * target: anterior horn of spinal chord * fine movement of ipsilateral limbs (though contralateral to motor cortex) * And **Anterior corticospinal tract** * **​**15 % of corticospinal tract * cross over in the spinal level they innervate * Then synapse at the **anterior horn** with the lower motor neuron * controls ipsi- and contralateral axial muscles

Question 36

Where is autonomic outflow from the spine? Which structural components relate to that?

Answer 36

Outflow fron grey matter lateral horn * PNS= Cranial Nerves III, VII, IX, X + S2-S4 * SNS= T1-L2

Question 37

Explain the two stages of injury to the lateral corticospinal tract

Answer 37

Stage 1. Spinal shock: loss of reflex activity below the lesion, lasting for days or weeks = flaccid paralysis Stage 2. Return of reflexes: hyperreflexia and/or spasticity = rigid paralysis

Question 38

How does a refley happen?

Answer 38

Sensoring fibres directly go to anterior horn (via the dorsal root) and synapse on motor fibres --\> convey a motor response without going to motor corte

Question 39

What it the Brown Séquad Syndrome?

Answer 39

It is a combination of symptoms resulting from a one-sided damage to the spinal chord resulting in * Paralysis and loss of proprioception on the ipsilateral side * Loss of pain and temperature sensation on contralateral side of lesion