Lab 2 Cranial Nerves

Question 1

What 3 structures make up the brainstem?

Answer 1

• midbrain
• pons
• medulla

Question 2

What is the tectum of the midbrain?

Answer 2

the region dorsal to the cerebral aqueduct

Question 3

What is the base of the brain stem?

Answer 3

the ventral aspect of brainstem

Question 4

What is the tegmuntum?

Answer 4

the brainstem region dorsal to the base and ventral to the cerebral aqueduct/4th ventricle [exists in midbrain/pons/medulla]

Question 5

What is the function of the substantia nigra in the midbrain?

Answer 5

• part of basal ganglia motor control system

Question 6

What is the function of cerebral peduncles in the midbrain

Answer 6

contains descending projections from cerebral cortex to brain and spinal cord

Question 7

What is the function of the red nucleus in the midbrain?

Answer 7

part of cerebellar motor control system

Question 8

What is the cerebral aqueduct in the midbrain?

Answer 8

part of ventricular system between 3rd and 4th ventricles

Question 9

What is the function of the periaqueductal grey in the midbrain?

Answer 9

pain perception and control and reflexes for orienting to the source of sensory stimuli

Question 10

What is the function of the superior collilculus in the midbrain?

Answer 10

sesnory-motor integration

Question 11

What is the function of the inferior colliculus in the midbrain?

Answer 11

auditory processing

Question 12

Which 3 nerves emerge from the midbrain?

Answer 12

• oculomotor [CN III]
• trochlear [CN IV]
• tract of CN V

Question 13

What part of the brainstem contains the caudal part of the 4th ventricle?

Answer 13

the medulla, rest is in pons

Question 14

What is the function of superior cerebellar peduncles?

Answer 14

contain efferent axons from cerebellum to the red nucleus and thalamus

part of motor control system

Question 15

What is the function of middle cerebella peduncles?

Answer 15

contain crossed projects from pontine nuclei to cerebellum

Question 16

What is the function of pontine nuclei?

Answer 16

relay between cerebral cortex and cerebellum

Question 17

What is the locus coeruleus?

Answer 17

nucleus that is principle site for brain NE production?

Question 18

What is the principle site of NE production in the brain?

Answer 18

locus coeruleus

Question 19

What structures are in the midbrain tectum?

Answer 19

XX

Question 20

What is the function of the two areas of the reticular formation? where are each located?

Answer 20

caudal portion: located in medulla and lower pons, involved in motor and autonomic function

rostral: in upper pons and midbrain, important for eye movement control and regulating level of consciousness

Question 21

What is the inferior olivary nucleus/complex?

Answer 21

part of cerebellar motor controll system

projects to opposite cerebellum via inferior cerebellar peduncle

Question 22

What is function of the medullary pyramids?

Answer 22

contain descending corticospinal axons/tracts

Question 23

Where does CSF drain from 4th ventricle into subarachnoid space?

Answer 23

• at lateral angles of the pontomedullary junction

Question 24

What is importance of inferior cerebellar peduncle

Answer 24

• integrates proprioceptive sensory input with motor vestibular
• important for balance and posture maintenance

Question 25

What is the raphe nuclei of the medulla?

Answer 25

group of nuclei that release serotonin

Question 26

What is the medial lemniscus?

Answer 26

- crossed fibers that carry somatosensory info through medulla, pons and midbrain to the thalamus - arises from dorsal columbs/gracile and cuneate nuclei and fasiculi

Question 27

What is important about the pyramidal decussation?

Answer 27

marks the boundary of medulla and spinal cord

Question 28

What is the obex?

Answer 28

point at which 4th ventricle narrows to become central canal of spinal cord

Question 29

What is locked in syndrome?

Answer 29

- pt aware and awake but cannot move or communicate due to complete paralysis of voluntary muscles in body - exception = can move eyes - result of brainstem lesion at level of pons

Question 30

What causes locked in syndrome?

Answer 30

- damage to brainstem at level of pons | - could be due to stroke or blockage at level of basilar artery [which gives rise to pontine arteries]

Question 31

What is the blood supply to the pons?

Answer 31

pontine arteries that come off of the basilar artery

Question 32

Why can cerebellar or tonsillar herniation be so deadly?

Answer 32

- causes compression of the lower brainstem - increased pressure on brainstem leads to dysfunction in brain centers responsible for respiratory control and cardiac function

Question 33

Are motor or sensory cranial nerve nuclei located more medially in the brainstem?

Answer 33

MOTOR = MEDIAL

Question 34

What 3 cranial nerve nuclei/nerves/tracts have GSA?

Answer 34

- trigeminal mesencephalic nucleus + tract - trigeminal prinicpal censory nerve - trigeminal spinal tract and nucleus

Question 35

what 1 sensory cranial nucleus has GVA/SVA?

Answer 35

solitary nucleus

Question 36

What 2 sensory cranial nerve nuclei have SSA fibers?

Answer 36

- vestibular nuclei | - cochlear nuclei

Question 37

What 4 motor cranial nerve nuclei have GSE fibers?

Answer 37

- oculomotor nucleus - trochlear nerve nucleus - abducens nerve nucleus - hypoglossal nerve nucleus

Question 38

What 3 motor cranial nerve nuclei have GVE fibers?

Answer 38

- Edinger-Westphal nucleus [III] - dorsal motor vagal nucleus - nucleus ambiguus

Question 39

What 4 cranial nerve nuclei have SVE fibers?

Answer 39

- trigeminal motor nucleus - facial nucleus - nucleus ambiguous - spinal accessor nucleus [of XI]

Question 40

Where does CN1 exit the brainstem?

Answer 40

- does not emerge from brainstem | - emerges directly from forebrain

Question 41

Where does CN2 exit from brainstem?

Answer 41

- - does not emerge from brainstem | - emerges directly from forebrain

Question 42

Where does CN3 exit from brainstem?

Answer 42

- ventrally | - from interpeduncular fossa of midbrain

Question 43

What is the gracile tract?

Answer 43

- medial portion of dorsal column | - sensory fibers from lower body

Question 44

What is the cuneate tract?

Answer 44

- lateral portion of dorsal column | - sensory fibers from upper body

Question 45

What does funiculus mean?

Answer 45

spinal cord white matter zone usually with more than one tract

Question 46

difference in function ventral vs dorsal horn?

Answer 46

- both grey matter - dorsal = sensory - ventral = motor

Question 47

What is intermediolateral cell column? where is it present?

Answer 47

- lateral side of grey matter horn - present in thoracic and lumbar - sympathetic preganglionic cell bodies

Question 48

What is clarke's nucleus? where is it located?

Answer 48

- in medial part of intermediate gray matter - present C8-L3 - part of cerebellar motor control system - conveys limb position info to cerebellum

Question 49

cervical enlargement?

Answer 49

C5-T1

Question 50

lumbar enlargement?

Answer 50

L2-S2