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
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/574/q_image_thumb.png?1544003444)
Decussation of lemniscus
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/575/q_image_thumb.png?1544003405)
Medial lemniscus
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/576/q_image_thumb.png?1544003471)
Cuneate nucleus
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/577/q_image_thumb.png?1544003485)
Gracile nucleus
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/586/q_image_thumb.png?1544003505)
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
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/589/q_image_thumb.png?1544003555)
Fasciculus cuneatus
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/590/q_image_thumb.png?1544003720)
Optic nerve (CN-II)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/591/q_image_thumb.png?1544003973)
Thalamus
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/592/q_image_thumb.png?1544004016)
Sensory area of neopallium
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/593/q_image_thumb.png?1544004043)
Medial lemniscus
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/594/q_image_thumb.png?1544004085)
Bulbothalmic tract
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/595/q_image_thumb.png?1544004104)
Spinothalmic tract
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/596/q_image_thumb.png?1544004138)
Pontine sensory nucleus of trigeminal nerve
![](https://s3.amazonaws.com/brainscape-prod/system/cm/262/960/598/q_image_thumb.png?1544004180)
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