Neuro lecture 7

Question 1

In the neural tube and eventual spinal cord the alar plate, is in what direction in relation to the sulcus limitans? what is the functions of the alar plate?

Answer 1

Dorsal to the sulcus limitans and largely afferent (sensory)

Question 2

In the neural tube and eventual spinal cord the basal plate, is in what direction in relation to the sulcus limitans? what is the function of the basal plate?

Answer 2

Ventrally to the sulcus limitans and largely efferent (motor).

Question 3

In brainstem development the dorsal portion of the neural tube (alar plate) rotates laterally, what significance does this play as far as location of certain cranial nerves?

Answer 3

this is the reason why the sensory cranial nerves are more lateral versus the primary motor CN are medially in location

Question 4

During brainstem development what does the central canal enlarge to become?

Answer 4

4th ventricle

Question 5

The midbrain contains which CN, ventrally? And what two other important structures, ventrally?

Answer 5

peduncles, interpeduncular fossa and CN III ventrally

Question 6

Which part of the brainstem houses the basilar groove? what is the importance of this groove?

Answer 6

pons and it houses the basilar artery

Question 7

The pons contains which CN, ventrally? which important structures, ventrally?

Answer 7

ventral aspects of the middle cerebellar peduncles (along with CN V-VIII)

Question 8

what is the only cranial nerve that emerges from the preolivary sulcus? and why?

Answer 8

CN XII because this nerve is only motor (mostly tongue movement) and therefore lies medially

Question 9

The midbrain dorsally contains what CN? what important structures dorsally?

Answer 9

Superior and Inferior Colliculi (corpora quadrigemina). CN IV

Question 10

what are the 4 afferent ascending tracts of the brainstem?

Answer 10

Dorsal Colum-Medial Lemniscal System, spinothalamic tract, lateral lemniscus, and trigeminal leminscus

Question 11

describe what the dorsal column-medial lemniscal system is responsible for

Answer 11

this is an ascending tract from the spinal cord to the body with synapses between the cuneate and gracile fasaciculi and nuclei.

Question 12

describe the spinothalamic tract (or anerolateral system)

Answer 12

carries pain

Question 13

describe the lateral lemniscus

Answer 13

audition

Question 14

Trigeminal lemniscus

Answer 14

sensory from the face

Question 15

name the two important efferent descending tracts

Answer 15

cortiobulbar and corticospinal

Question 16

Reticular formation contains several elongated cell groups throughout the brainstem. Name some of the functions of this distinct cell groups

Answer 16

Arousal, coordination of chewing, licking or sucking, swallowing, vasomotor, inspiration, vomiting, expiration and inspiration

Question 17

Give the reasoning why someone with a brain injury, however the brain stem is still intact, can still lick swallow or lick/

Answer 17

because the reticular fibers that are responsible for these actions are in the brainstem and the brainstem is still intact.

Question 18

A defect in what results in the patient being unable to touch their nose to your finger? (they will either under shoot or over shoot)

Answer 18

cerebellar tract, the exact tract will be covered in later lectures. but many motor and sensory systems communicate with the cerebellum and the brainstem mediates all such communications.

Question 19

The Anterior Inferior Cerebellar Arteries (AICA) emerge laterally from the basilar artery supply which CNs?

Answer 19

CN VII and VIII

Question 20

what group of arteries supply the core and lateral aspects of the pons?

Answer 20

Pontine Arteries

Question 21

what supplies the caudal midbrain?

Answer 21

Superior Cerebellar Arteries

Question 22

which artery is associated with CN IV

Answer 22

Superior Cerebellar Arteries

Question 23

which artery supplies CN III?

Answer 23

Posterior Cerebral Arteries

Question 24

what are the three arteries that supply the midbrain?

Answer 24

posterior cerebral, superior cerebellar and posterior communicating (which again comes from the internal carotid artery)

Question 25

what is the blood supply of the medulla?

Answer 25

PICA, AICA and Anterior Spinal (medial)

Question 26

Occlusion of what artery or branches of this artery results in Wallenberg Syndrome?

Answer 26

PICA or branches of PICA, to the dorsolateral medulla

Question 27

Name some of the deficits seen in a patient with lateral medullary syndrome

Answer 27

Contralateral loss of pain and thermal sense on body
Ipsilateral loss of pain and thermal sense on body
Dysphagia, soft palate paralysis, horsiness and diminished gag reflex
Ipsilateral miosis, ptosis, anhidrosis, flushing of face)
Ataxia to the ipsilateral side

Question 28

Why is dysphagia and dysarthria seen in patients with lateral medullary syndrome?

Answer 28

Efferents of CN IX and X are present in the medulla