Pathways Flashcards
What are the three ascending pathways?
DCML
Spinothalamic tract
Spinocerebellar pathway
What are the 3 functions of the DCML?
Fine touch
Proprioception
Vibration
What does DCML stand for?
Dorsal column-medial lemniscus
Where does the DCML desiccate?
Medulla
What are the two components of the DCML?
Nucleus cuneatus
Nucleus Gracillis
To which somatosensory cortex is the information transmitted to?
CONTRALATERAL
Function of the spinothalamic tract
Lateral- Pain and temperature
Anterior- Crude touch
Where do the two conscious ascending pathways of the brain enter the spinal cord?
The posterior root ganglia
Where does the spinothalmaic tract cross over?
1 or 2 spinal segments above through tract of lissauer to synapse in the dorsal horn
At what level does the spinothalamic tract dessucate?
Spinal level
Which somatosensory cortex is the information in the spinothalamic tract transmitted to?
Contralateral
What is the name of the pathways that carries unconscious proprioceptive information to the cerebellum
Spinocerebellar pathways
What two things does the spinocerebellar pathway coordinate?
Movement and posture
What are the 3 types of spinocerebellar pathway
Dorsal/posterior spinocerebellar
Cuneocerebellar
Ventral/Anterior spinocerebellar
Where does the dorsal/posterior spinocerebellar tract carry information from?
the lower limbs
Where does the dorsal/posterior spinocerebellar tract synapse?
dorsal nucleus of Clarke
Where does the cuneocerebellar carry unconscious proprioceptive information from
The upper limbs
Where does the ventral/anterior spinocerebellar pathways carry unconscious proprioceptive information from?
The lower limbs (Golgi tendon organs mainly)
The spinocerebellar pathway transmits information to which somatosensory cortex?
Ipsilateral
Conscious pathways have a —– neuron chain?
3
What are the names of the two pyramidal descending pathways?
Corticospinal
Corticobulbar
Corticospinal conveys voluntary skilled movements from the cortices to the ——– of the medulla
pyramids
85% of the fibres of the corticospinal tract cross in the medulla and form the ——-
lateral CST
What does the lateral CST carry?
Motor information for limb
Uncrossed fibres of the corticospinal tract form the ——-
Ventral CST
What does the ventral CST carry?
Motor information for central
If there is a CVA of the internal capsule there will be a lack of descending controls of the corticospinal tract. What does this clinically look like?
Spastic paralysis and hyperflexion of the upper limbs (Decorticate posturing)
TRUE/FALSE Corticobulbar provides motor to the CN that supply the face
TRUE
What are the CN that supply the face?
V,VII,X,XII
Most inputs from the corticobulbar are bilateral. Which two nerves are innervated contraleterally only?
Lower facial nerve
Hypoglossal nerve
UMN lesions affecting facial nerve clinically looks like…
paralysis to lower side of one half of the face ONLY and forehead unaffected (central facial palsy)
A LMN lesion affecting the face clinically looks like… and is called
Paralysis of the ipsilateral one-half of the face inc forehead (Bells palsy)
What are the 4 extrapyramidal tracts called?
Rubrospinal
Vestibulospinal
Rectospinal
Tecto-spinal tracts
Where do Rubrospinal tract originate?
Red nucleus
What is the rubrospinal tract responsible for
limb flexors (and inhibit extensors)
What do the fibres in the vestibulospinal tract control?
Balance and posture by innervating anti-gravity muscles
Where does the tectonic-spinal tract originate?
Superior colliculus
If there is a lesion above the midbrain which of the extrapyramidal tracts will be working
rubrospinal
reticulospinal
