Cranial Nerve Nuclei Columns & Long Tracts

Question 1

GSE

Answer 1

3, 4, 6, 12 (purely motor cranial nerves innervating “garden variety” skeletal muscle)

Question 2

GVE

Answer 2

Edinger-Westphal (3), Superior Salivatory (7), Inferior Salivatory (9), Dorsal Motor Nucleus of X (10) – preganglionic parasympathetics

Question 3

SVE

Answer 3

Motor nucleus of V, Motor nucleus of VII, Nucleus Ambiguus (IX, X) (pharyngeal arch derivative muscles, some parasympathetics from X to the heart)

Question 4

SVA/GVA

Answer 4

Solitary Nucleus (VII, IX, X): tase (upper), carotid sinus and carotid body (lower)

Question 5

SSA

Answer 5

Vestibular, cochlear nuclei (VIII)

Question 6

GSA

Answer 6

Trigeminal nuclei: mesencephalic (proprioception from face), main/chief/primary (touch from face); spinal (pain and temperature)

Question 7

Spinal Trigeminal Nucleus – subparts

Answer 7

Nucleus oralis (facial touch), Nucleus interpolaris (tooth pulp pain), Nucleus caudalis (pain, temperature of face)

Question 8

Relay nucleus of V

Answer 8

VPM

Question 9

Medial Lemniscus projects to

Answer 9

VPL of thalamus

Question 10

Spinothalamic tract projects to

Answer 10

VPL of thalamus

Question 11

Corticospinal tract descends from

Answer 11

Premotor cortex, Primary motor cortex

Question 12

Corticobulbar tract

Answer 12

UMNs –> LMN to cranial nerve innervated muscles; generally bilateral innervation

Question 13

Which cranial nerve is not actually a nerve but a tract of the CNS?

Answer 13

Optic nerve (CN II)

Question 14

Where do crossing fibers of CST synapse in the cord?

Answer 14

On Alpha or Lower motor neurons in the ventral horn of the cord.

Question 15

Internal arcuate fibers

Answer 15

ascending fibers from dorsal column nuclei, will form the medial lemniscus after they cross

Question 16

Difference in lesion @ n. gracilis and medial lemniscus

Answer 16

N. gracilis: loss of vibration, proprioception in ipsilateral lower trunk, lower limb
ML: loss of vibration, proprioception in contralateral trunk & limbs

Question 17

External (lateral) cuneate nucleus

Answer 17

unconscious proprioception from upper limb –> deep cerebellar nuclei (Mossy fibers)

Question 18

What nucleus in the cord has a similar function to the external cuneate?

Answer 18

Clarke’s

Question 19

Where do the axons of the inferior olivary nuclei project & synapse?

Answer 19

The olivary axons cross and project into the contralateral cerebellum and synapse directly with Purkinje cells and send collaterals to the deep Cb nuclei

Question 20

Reticular formation

Answer 20

The reticular formation is a region in the brainstem that is involved in multiple tasks such as regulating the sleep-wake cycle and filtering incoming stimuli to discriminate irrelevant background stimuli.Important motor axons: central pattern generators

Question 21

Nuclei that send axons into ICP and their side of origin

Answer 21

Ipsilateral Clarke’s nucleus in the cord, Contralateral inferior olive in the medulla,
Ipsilateral External cuneate nucleus in the medulla, Ipsilateral vestibular nuclei.

Question 22

input to MCP

Answer 22

pontine nuclei (contralateral)

Question 23

what axons course in SCP?

Answer 23

Axons exiting the Cb from the deep nuclei and axons entering in the ventral spinocerebellar tract.

Question 24

Where do axons from SCP project?

Answer 24

Out to various collections of upper motor neurons in the brainstem ( red nucleus, reticular formation) and to the VL nucleus of the thalamus

Question 25

Lateral lemniscus

Answer 25

The lateral lemniscus is a tract of axons in the brainstem that carries information about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain.

Question 26

What are the subdivisions of the substantia nigra and what NTs do they use?

Answer 26

Pars compacta (Dopaminergic neurons)
Pars reticularis (GABAergic neurons)

Question 27

cell bodies of axons in spinal trigeminal tract

Answer 27

trigeminal ganglion

Question 28

What three cranial nerves send axons into the solitary tract, and what are their functions?

Answer 28

VII, IX, X; taste & carotid body/sinus

Question 29

What does the anterior thalamic nucleus do?

Answer 29

Receives input from mammillothalamic tract (via mammillary bodies), projects to cingulate gyrus

Question 30

Uncinate fasciculus

Answer 30

The uncinate fasciculus is a white matter tract in the human brain that connects parts of the limbic system such as the hippocampus and amygdala in the temporal lobe with frontal ones such as the orbitofrontal cortex