2: Spinal Chord Function and Dysfunction Flashcards
How many pairs of spinal nerves are there?
How are they classified?
31 Pairs
- 8 Cervical
- 12 Thoracic
- 5 Sacral
- 5 Lumbar
- 1 Coccyngeal
How do nerves leave the vertebra colum?
•Nerves leave the vertebral column through intervertebral foramina
Where are normal enlargements of the spinal chord found?
Why?
Enlargements for innervation of the limbs:
- Cervical (C3-T1)
- Lumbar (L1-S3)
How do spinal levels and vertebra levels relate to one another?
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
How is the organisation of the meningeines in the spinal chord different from the one in the Brain?
In spinal chord
- ther is space between the Dura Mater and the Bone
–> has a physiological epidural space (relevant for e.g. anestesia)
What is the difference between a root and a ramus?
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)
What are the neurological termes used for
- Anterior
- Posterior
- Superior
- Inferior
Anterior= Ventral
Posterior = Dorsal
Superior = Rostal
Inferior = Caudal
Name + Function
Posterior Colum:
- Sensory (touch, pain etc.) from ipsilateral limbs
Name + Function
- Pain and Temperature from contralateral side to body
- Motor to ipsilateral anterior spinal horn
- Proprioception (Gefühl von Selbstbewegung und Körperhaltung) from limbs to cerebellum
Name + Function
Motor to ipsi and contralateral anterior horn
What does the Faciculus gracilis spinal tract controll? Where is it Situatied?
It is located in posterior colum:
- Sensory (touch, vibration , proprioception) from ipsilateral lower limb)
What is the Faciculus Cuneatus?
Where is it situated?
Posterior Colum
- Sentory (touch, vibration etc.) from ipsilateral upper limb
Where is the spinocerebellar tract located?
What is its function?
Located in the lateral column:
- conveys proprioception (Gefühl von Selbstbewegung und Körperhaltung) from limbs to cerebellum
What is the function of the Lateral Corticospinal tract?
Where is it situated?
- Located at latereal colum
- Conveys motor infromation to ipsilateral anterior horn (mostly for limb musculature)
What it hte function of the Spinothalamic tract?
Where is is located?
Conveys Pain and Temperarture from contralateral side of body (crosses when entering)
- Located in lateral colum (around anterior horn)
What is the function of the anterior coticospinal tract? Where is it located?
- 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
What is the anterior white commisure?
Part of spinal chord where
- pain and temperature fibres
- Anteriorcorticospinal tract fibres
cross
What does decussation mean?
The crossing over of nerve fibres
Explain the route and function of the dorsam colum pathways
- Fasciculus gracilic and Fasciculus Cuneatus
- Discriminative touch, vibration, proprioception
- 2nd. neurone crosses over at Medulla
Compare the two main sensory pathways (Dorsal colum pathway and spinothalamic tract) in regard to their route to the brain.
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)
Explain the function and route of the corticospinal tract
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
Where is autonomic outflow from the spine?
Which structural components relate to that?
Outflow fron grey matter lateral horn
- PNS= Cranial Nerves III, VII, IX, X + S2-S4
- SNS= T1-L2
Explain the two stages of injury to the lateral corticospinal tract
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
How does a refley happen?
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
What it the Brown Séquad Syndrome?
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
