Ascending tracts Flashcards
What are 3 main ascending tracts?
DCML pathway
Spinothalamic pathway
Spinocerebellar tracts
What 2 main conscious ascending tracts?
DCML
Spinothalamic
What is main unconscious tract?
Spinocerebellar
What is unconscious ascending tract?
Spinocerbellar
What is conscious ascending tracts? (2)
DCML pathway
Spinothalamic
What does DCML tract sense?
Fine touch
Vibration
Proprioception
How does information travel up DCML?
Spinal cord- Dorsal columns
Brainstem- Medial lemniscus
How many order neurones DCML?
3
First order
Carry sensory info from peripheral nerves to medulla
Signals upper limbs (T6+)- travel in fasciculus cuneatus
- synapse in nucleus cuneatus
Signals from lower limbs- travel in fasciculus gracilis
- synapse in nucleus gracilis
Second order
From cuneate of gracilis nuclei fibres carry info to 3rd order neurons
Decussate in medulla- travel contralateral thalamus
Third order neurons
Transmit sensory info to thalamus and ipsilateral primary sensory cortex
In DCML where do signals from upper limbs travel?
Where do synapse?
Signals upper limbs (T6+)- travel in fasciculus cuneatus
- synapse in nucleus cuneatus
In DCML where do signals from lower limbs travel?
Where do synapse?
Signals from lower limbs- travel in fasciculus gracilis
- synapse in nucleus gracilis
Grass- low
In DCML where do second neurons decussate?
Medulla
Travel to contralateral thalamus
Function of third order neuron in DCML?
Transmit sensory info to: thalamus
ipsilateral primary sensory cortex
What does spinothalamic tracts consist of?
2 tracts
Anterior spinothalamic tract- Crude touch and pressure
Lateral spinothalamic tract- Pain and temperature
What does spinothalamic tract relay?
Anterior- Crude touch and pressure
Lateral- pain and temperature
How many neurons in spinothalamic tract?
3
First order
Arise sensory receptors in periphery
Enter spinal cord and synapse at tip dorsal horn
Second order
Carry info from dorsal horn to thalamus
Fibres decussate in spinal cord
Third order neurons:
From thalamus to ipsilateral primary sensory cortex
Where does spinothalamic tract decussate?
Spinal cord
