Sensation from the face, the mouth and the front of the head does not travel up the spinal cord: it enters the brainstem through the trigeminal nerve and relays in two nuclei of its own. The chapter is short, and your book warns that long questions are rarely set from it. What does get asked is the trigeminal pathway as a short note, and in the viva the innervation of the face and the basis of trigeminal neuralgia.
Topics, in the book’s order
- Trigeminal pathway and trigeminal neuralgia · pp. 1024–1025
When you’ve read them: Quiz 121 · Trigeminal System, 10 questions.
After this chapter you should be able to
- say why the trigeminal system is the one to study when learning how facial pain and analgesia work
- draw and label a schematic of the trigeminal pathways
- name the three divisions of the nerve and the part of the face each of them covers
- describe where trigeminal fibres end in the thalamus, and which nucleus feeds which
- explain the physiological basis of trigeminal neuralgia, and how it is treated
Viva checklist
- What the trigeminal nerve supplies, and why a map of body sensation is incomplete without it
- The three divisions, and the region of the face each one covers
- Where the first-order cell bodies sit, and what shape of neuron they are
- The two brainstem nuclei, and the size of fibre each of them takes
- The three subdivisions of spinal V from above downwards, and the input of each
- Which subdivision is lesioned surgically for facial pain that will not settle
- Why spinal V is called the spinothalamic system of the trigeminal nerve
- Which nucleus is the face’s version of the dorsal column nuclei, and why
- The tract that carries trigeminal fibres to the thalamus, and what it runs beside
- Which thalamic nuclei receive trigeminal input, and which nucleus sends to each
- Why the face occupies such a large stretch of the sensory cortex
- Whether SII receives trigeminal input as well as SI
- How the trigeminal pain pathway differs from the pain pathway of the rest of the body
- Trigeminal neuralgia: the character of the pain, the trigger zone, the cause, the treatment