Lab 8 Structures

Question 1

what structures can you use to identify the lower/mid level medulla cross section?

Answer 1

• pyramids
• gracile/cuneate fasciulus/nuclei
• hypoglossal nucleus
• obex
• inferior olivary nucleus

Question 2

gracile/cuneate nucleus and fasciculus

medulla → level of sensory decussation

Answer 2

red → gracile nucleus pink → gracile fasciculus dark blue → cuneate nucleus light blue → cuneate fasciculus

Question 3

lateral (accessory) cuneate nucleus

medulla → level of sensory decussation

Answer 3

serves as synapse site for 1st order neuron of cuneocerebellar tract

Question 4

internal arcuate fibers and medial lemniscus

medulla → level of sensory decussation

Answer 4

• arcuate fibers are 2nd order neurons of DCML tract leaving the dorsal column nuclei and crossing to contralateral medulla
• medial lemniscus: the bundle of crossed fibers

red → path of fibers

Question 5

medial longitudinal fasciculus (MLF)

medulla → level of sensory decussation

Answer 5

white matter pathway that contains descending vestibular information and ascending conjugate gaze control

Question 6

trigeminothalamic tract

medulla → level of sensory decussation

Answer 6

crossed tract carrying ascending sensory information from face

Question 7

spinal trigeminal nucleus and tract

medulla → level of sensory decussation

Answer 7

associated with pain and temperature info from face

red → spinal trigeminal tract purple → spinal trigeminal nucleus

Question 8

spinothalamic tract

medulla → level of sensory decussation

Answer 8

Question 9

pyramids/corticospinal tract

medulla → level of sensory decussation

Answer 9

Question 10

hypoglossal nucleus

medulla → level of sensory decussation

Answer 10

Question 11

dorsal motor nucleus of vagus

medulla → level of sensory decussation

Answer 11

Question 12

solitary nucleus/tract

medulla → level of sensory decussation

Answer 12

taste to posterior 1/3 of tongue (CN IX)

Question 13

nucleus ambiguus

medulla → level of sensory decussation

Answer 13

motor functions of CN IX and CN X

Question 14

obex

medulla → level of sensory decussation

Answer 14

region of median aperature closest to 4th ventricle

Question 15

inferior (principal) olivary nucleus

medulla → level of sensory decussation

Answer 15

• gives rise to climbing fibers to cerebellum
• nucleus deep to external olive

Question 16

reticular formation

medulla → level of sensory decussation

Answer 16

• diffuse nuclei throughout regions of brainstem
• serve variety of functions (e.g. reticulospinal tracts, pain modulation, cardiac/pulmonary functions)

Question 17

what structures can you use to identify the upper level medulla cross section?

Answer 17

Question 18

spinothalamic tract (ALS)

rostral medulla → level of ICP

Answer 18

Question 19

spinal trigeminal nucleus/tract

rostral medulla → level of ICP

Answer 19

red → spinal trigeminal tract purple → spinal trigeminal nucleus

Question 20

medial lemniscus

rostral medulla → level of ICP

Answer 20

Question 21

medial longitudinal fasciculus (MLF)

Answer 21

Question 22

pyramids

rostral medulla → level of ICP

Answer 22

Question 23

descending sympathetic fibers

rostral medulla → level of ICP

Answer 23

• associated with pupillary dilation, elevation of eyelid, sweating to face
• ipsilateral impact if lesioned

Question 24

cochlear nuclei (dorsal, ventral)

rostral medulla → level of ICP

Answer 24

associated with aspects of hearing

red → dorsal purple → ventral

Question 25

vestibular nuclei (medial, inferior)

rostral medulla → level of ICP

Answer 25

Question 26

glossopharyngeal nerve

rostral medulla → level of ICP

Answer 26

Question 27

solitary nucleus/tract

rostral medulla → level of ICP

Answer 27

taste to posterior 1/3 of tongue (CN IX)

Question 28

nucleus ambiguus

rostral medulla → level of ICP

Answer 28

motor functions of CN IX and CN X

Question 29

inferior olivary nucleus

rostral medulla → level of ICP

Answer 29

Question 30

inferior cerebellar peduncle (restiform body)

rostral medulla → level of ICP

Answer 30

Question 31

what structures can you use to identify the caudal pons cross section?

Answer 31

Question 32

medial longitudinal fasciculus

caudal pons

Answer 32

Question 33

medial lemniscus (orientation)

caudal pons

Answer 33

Question 34

trigeminothalmic tract

caudal pons

Answer 34

Question 35

spinothalamic tract (ALS)

caudal pons

Answer 35

Question 36

corticospinal tract (CST) and corticobulbar

caudal pons

Answer 36

red → CST purple → corticobulbar

Question 37

spinal trigeminal nucleus/tract

caudal pons

Answer 37

red → tract purple → nucleus

Question 38

vestibular nuclei

caudal pons

Answer 38

Question 39

facial colliculus

caudal pons

Answer 39

externally located (deep is abducens nucleus and facial nerve)

Question 40

facial nucleus, facial nerve

caudal pons

Answer 40

red → nucleus purple → nerve

Question 41

abducens nucleus, nerve

caudal pons

Answer 41

red → nucleus purple → nerve

Question 42

sulcus limitans

caudal pons

Answer 42

Question 43

superior cerebellar peduncle

caudal pons

Answer 43

Question 44

reticular formation

caudal pons

Answer 44

collection of diffuse nuclei located in posteriomedial region of medulla, pons, midbrain

Question 45

pontine nuclei

caudal pons

Answer 45

receive information from cortex and relays information to cerebellum via cerebropontocerebellar fibers

Question 46

(cerebro)pontocerebellar axons

caudal pons

Answer 46

relays information from pontine nuclei to contralateral cerebellum through MCP

Question 47

4th ventricle

caudal pons

Answer 47

Question 48

what structures can you use to identify the upper midbrain cross section?

Answer 48

Question 49

corticospinal tract (CST)/bulbar fibers

midbrain → level of superior colliculus

Answer 49

Question 50

medial lemniscus

midbrain → level of superior colliculus

Answer 50

Question 51

spinothalamic fibers

midbrain → level of superior colliculus

Answer 51

Question 52

trigeminothalamic tract

midbrain → level of superior colliculus

Answer 52

Question 53

oculomotor nucleus

midbrain → level of superior colliculus

Answer 53

Question 54

oculomotor nerve

midbrain → level of superior colliculus

Answer 54

Question 55

pulvinar nuclear complex

midbrain → level of superior colliculus

Answer 55

• most posterior nucleus of thalamus
• associated with visuomotor behaviors, body awareness/attention

Question 56

medial/lateral geniculate nucleus

midbrain → level of superior colliculus

Answer 56

red → lateral purple → medial

Question 57

cerebral aqueduct

midbrain → level of superior colliculus

Answer 57

Question 58

periaqueductal grey (PAG)

midbrain → level of superior colliculus

Answer 58

• gray matter surrounding cerebral aqueduct
• associated with pain modulation

Question 59

Edinger-Westphal nucleus

midbrain → level of superior colliculus

Answer 59

gives rise to pre-ganglionic parasympathetic fibers associated with pupillary constriction of eye

Question 60

red nucleus

midbrain → level of superior colliculus

Answer 60

Question 61

substantia nigra

midbrain → level of superior colliculus

Answer 61

source of dopaminergic fibers

Question 62

cerebral peduncles

midbrain → level of superior colliculus

Answer 62

Question 63

interpeduncular fossa

midbrain → level of superior colliculus

Answer 63

Question 64

superior colliculus

midbrain → level of superior colliculus

Answer 64

Question 65

label pons blood supply

Answer 65

Question 66

label midbrain blood supply

Answer 66