With 100% Correct Answers 2026
Updated.
What are the 3 functions of the brainstem? - Answer 1. Cranial nerve
2. Integrative
3. Conduit - relay info from periphery to the thalamus, modulate motor activity
Key components of the spinomedullarly junction - Answer Nucleus gracilis
Pyramidal decussation
Spinal trigeminal tract and nucleus
Key components of the caudal medulla - Answer Nucleus gracilis and cuneatus
Pyramids
Spinal trigeminal tract and nucleus
Key components of rostral medulla - Answer Dorsal motor nucleus X
Hypoglossal nucleus
Inferior olivary nucleus
Nucleus ambiguus
Solitary tract and it's nucleus
Spinal trigeminal tract and nucleus
Vestibular nuclei
Key components of pontomedullarly junction - Answer Cochlear nuclei
Spinal trigeminal tract nucleus
Vestibular nuclei
Where is the pyramidal decussation? - Answer Spinomedullary Junction
Caudal to obex
Axons cross midline and move dorsally
What axons make up the pyramids? - Answer Axons of the corticospinal tract (motor)
,What do the dorsal funiculi (columns) contain? - Answer Large diameter processes of dorsal
root ganglia neurons
Where are the fasciculus gracilis and fasciculus cuneatus in relation to each other? - Answer
FG is medial
FC is lateral
What do the axons in the fasciculus gracilis carry? - Answer Touch information from the lower
limb (Below T6)
What do the axons in the fasciculus cuneatus carry? - Answer Touch information from the
upper limb (above and including T6)
Where do the fasciculus gracilis and cuneatus carry information? - Answer From the DRG
neurons to the medulla
True or false: All levels of the spinal cord contain both fasciculus gracilis and fasciculus
cuneatus? - Answer False: levels below T6 only contain fasciculus gracilis
What happens to the fasciculus gracilis when the fasciculus cuneatus emerges at T6? - Answer
FG is shifted medially
What information does the spinal tract of V carry? - Answer Pain and temperature from the
face
What forms the gracile tubercle (external)? - Answer Gracile nucleus (internal)
What order, from caudal to rostral, do the trigeminal nucleus, gracile nucleus, and cuneate
nucleus arise? - Answer Trigeminal nucleus (most caudal)
Gracile nucleus (middle)
Cuneate nucleus (most rostral)
What order, from medial to later, do the trigeminal nucleus, gracile nucleus, and cuneate
nucleus arise? - Answer Nucleus gracilis (most medial)
Nucleus cuneatus (middle)
Trigeminal nucleus (most lateral)
, How does the organization of NG, NC and SpV differ? - Answer NG and NC are ascending
paths, so as we move rostrally, their nuclei get bigger while their tracts get smaller.
SpV forms a descending path, so as we move rostrally, the nucleus gets smaller and the tract
gets bigger
How does the medulla cross section change after it's rostral to the medulla? - Answer The
inferior olivary nucleus is expanded and forms protuberance on ventral surface of medulla
Dorsal surface begins to open up
NG and NC are no longer present
Nuclei relating to cranial nerves arise
Which cranial nerves are located at the ponto-medullary junction? - Answer Abducens, facial,
vestibulocochlear
Which cranial nerves are located at the post-olivary sulcus? - Answer Glossopharyngeal, vagus
Which cranial nerves is at the pre-olivary sulcus? - Answer Hypoglossal
True or false: There are more nuclei related to cranial nerves than there are cranial nerves -
Answer True; because each component in a CN has a unique nucleus in brainstem relating to it
True or false: cranial nerve nuclei are generally present in the caudal medulla - Answer False -
the vast majority are present in the rostral medulla, pons, midbrain, and diencephalon
Describe the organization of the developing spinal cord - Answer From dorsal to ventral:
Somatic sensory
Visceral sensory
Visceral motor
Somatic motor
Describe the organization of the brainstem as the 4th ventricle "opens" the brainstem - Answer
Structures that were located dorsally in the spinal cord (somatic sensory, visceral sensory) are
shifted laterally whereas structures that were ventral (somatic motor, visceral motor) move
dorsally and medially)