THRC.7 Flashcards
The tracts of the CNS can be divided into…
- Ascending pathways
- Descending pathways
What are the divisions of the ascending pathways?
- Medial lemniscus
- Extra-lemniscal system
List the ascending pathways
- Visual
- Vestibular + auditory
- Somatic afferent pathways
The medial lemniscus can be divided into…
- Spinal lemniscus (trunk + limbs)
- Trigeminal lemniscus (sensory nerves of the head)
The sensory neurons of the spinal lemniscus run along…
The dorsal funiculus of the spinal cord
Decussation of lemniscus
Medial lemniscus
Cuneate nucleus
Gracile nucleus
Fasciculus gracilis
Tracts from the caudal trunk + lumbosacral plexus are located…
- Medially:
- Fasciculus gracilis
Tracts from the cranial trunk + brachial plexus are located…
- Laterally:
- Cuneate fascicle
Fasciculus cuneatus
Optic nerve (CN-II)
Thalamus
Sensory area of neopallium
Medial lemniscus
Bulbothalmic tract
Spinothalmic tract
Pontine sensory nucleus of trigeminal nerve
Gracile + cuneate nucleus
Where does the lateral-most tract terminate?
Nucleus cuneatus of dorsal medulla oblongata
Where does the medial-most tract terminate?
Nucleus gracilis of dorsal medulla oblongata
Where does the medial lemniscus join with sensory fibres of the trigeminal nerve?
The brain stem
Which tract is formed by the extra-lemniscal system?
Spinothalamic tract
Give the termination pathway of the spinothalamic tract
- Neurons of the dorsal horns (close to spinal root) →
- White matter → Ventrolateral funiculi
- Thalamus
- Some tertiary neurons project more rostrally