W2:S5 - Sections of Spinal Cord Flashcards
Which part of the spinal cord is this from?
Thoracic
- Thin grey and white matter area
- Long dorsal horn
What part of the spinal cord is this from?
Cervical
- Note the cervical enlargement of grey matter BUT
- Large amount of white matter too
What part of the spinal cord is this from?
Lumbar
- Note the enlarged grey matter from the lumbar enlargement
- Much more grey matter than white matter
What causes the enlargement of the grey areas in the dorsal horns of the cervical and lumbar areas?
- Limbs
- Dorsal horns are motor fibres
What does the dorsal column medial lemnisal pathway carry?
- Fine touch
- Vibration sense
- Proprioreception
How many neurones are there in a pathway in the dorsal medial lemniscus pathway?
3
First order
Second order
Third order
Where do first order neurones from the upper limb travel in the dorsal medial lemniscus pathway?
The fasciculus cuneatus
Where do signals from the first order neurones of the upper limb synapse?
Nucleus cuneatus
Where do first order neurone signals from the lower limb travel in the dorsal medial lemniscus column?
Fasciculus gracillis
Where do signals from the first order neurones of the lower limb synapse?
Nucleus gracillis
What is the pathway of second order neurones in the dorsal column medial lemniscus pathway?
Arise in nucleus gracillis and nucleus cuneate
- Decussate in the medulla
- Travel up in the controlateral medial lemniscus
- They synapse in the posterolateral nuclei in the thalamus
Where do third order neurones travel in the DCML?
- arise in posterolateral nuclei of the thalamus
- Travel to the ipsilateral primary somatosensory cortex through the internal capsule to form the sensory homunculus
- Remember they have already crossed over
Summary of DCML tract
What fibres travel in the antermedial spinothalamic tract?
Sensory
- Crude touch
- Pressure