Neuroanatomy Lab Ii

Front 1

How far down does DLF extend?

Back 1

(dorsal longitudinal fasciculus)

Front 2

How far down does DLF extend?

Back 2

(dorsal longitudinal fasciculus)

Only to the brainstem

Front 3

What is DLF thought to be involved in?

Back 3

Regulation of cranial parasumpathetic neurons

Front 4

How far down does the MFB project?

Back 4

(Medial forebrain bundle)

Down to sacral spinal cord

Front 5

What, generally, does the MFB influence?

Back 5

In the spinal cord, it influences both the sympathetic and parasympathetic divisions of the autonomic nervous system by terminating on preganglionic neurons in the brainstem and spinal cord.

Front 6

Can you see the MFB distinctly in the anatomical sections?

Back 6

No

Front 7

Where is the MFB in the brainstem?

Back 7

Dorsolateral position in the tegmentum in the brainstem

Front 8

Where is MFB in the spinal cord?

Back 8

It overlaps the region of the corticospinal tract in the dorsolateral funiculus

Front 9

What does horner's syndrome include?

Back 9

Pupillary constriction
Ptosis of eyelid
Decreased sweating (anhydrosus)

Front 10

What happens if you interrupt the MFB at, say, the cervical spinal cord level?

Back 10

Impair control of symp neurons below level of lesion.

This results in a horner's syndrome

(Oddly, sacral parasympathetic functionsbelow level of lesion are relatively unaffected, probably due to bilateral MFB input to parasymp preganglionic neurons)

Front 11

Describe how descending pathways can ihibit ascending nociceptive signals?

Back 11

1) descending paths originating in cortex project to the PERIAQUEDUCTAL GRAY
2) this projects to the RETICULAR FORMATION and the RAPHE NUCLEI of th emedulla.
3) These targes send their axons to trigem nuclei and the dorsal horn of the cord to inhibit neurons transmitting nociceptive info

Front 12

What Neurotransmitter do reticular formation neurons use?

Back 12

NE

Front 13

What Neurotransmitter do neurons of the raphe nuclei use?

Back 13

serotonin

Front 14

What happens to descending tracts if you lose anterior spinal artery at cord level?

Back 14

1) ipsilateral loss of voluntary motor control below the lesion (CST)
2) disruption of spinal reflexes AT THE LEVEL of the lesion

Front 15

What descending tracts do you lose with anterior spinal artery loss at level of of caudal medulla?

Back 15

1) loss of volontary motor control below the lestion, bilateral or unilateral (?)

Front 16

What descending tracts do you lose with brown-sequard syndrome?

Back 16

1) ipsoilateral loss of voluntary movement below lesion (CST; RST if cervical)

Front 17

What descending tracts do you lose with medial pointine syndrome?

Back 17

1) contralateral loss of voluntary movement of body below the lesion (CST)

2) ipsilateral paralysis of face (facial nerve)

Front 18

What descending control do you lose with lateral pontine syndrome?

Back 18

1) ipsilateral loss of voluntary movement of upper and lower face

Front 19

What descending control do you lose with middle cerebral artery occlusion at posterior limb of internal capsule?

Back 19

1) contralateral loss of voluntary body movement
2) contralateral loss of voluntary movement of LOWER face

Front 20

Where is the red nucleus?

Back 20

midbrain

Front 21

what does rubrospinal tract run alongside/with

Back 21

axons from lateral corticospinal tract

Front 22

What is rubrospinal tract mainly involved wiht

Back 22

distal arm motor function

Front 23

If you could injure ONLY the rubrospinal tract somehow, would you get a clinical manisfestation?

Back 23

probably not. seems to be fairly redundant.

Front 24

Where does rubrospinal tract decussate?

Back 24

Pretty musch right at level of red nucleus in midbrain.

Front 25

Where is position of rubrospinal tract in the spinal cord?

Back 25

Lateral...pretty much with the LCST.

Front 26

Where does tectospinal tract originate?

Back 26

also midbrain (like rubrospinal, I think)

Front 27

When does tectospinal tract decussate

Back 27

Pretty much immediately

Front 28

Where does tectospinal tract run in the spinal cord

Back 28

Down ventrally with the VSCT

Front 29

Where does rubrospinal tract end?

Back 29

cervical cord

Front 30

Where does tectospinal tract end?

Back 30

cervical cord

Front 31

Where is rubrospinal tract in the cord in relation to LCST?

Back 31

Just ventral to it

Front 32

Where can you see dorsal longitudinal funiculus?

Back 32

On surfaces of the bumps in dorsal surface of mid medulla section

Front 33

Where does caudal extension of median forebrain bundle run?

Back 33

Runs indistincly near the spinolthalamic tract

Front 34

What does caudal extension of the medial forebrain bundle carry?

Back 34

1) sympathetic control fibers
2) parasymp control fibers to sacral cord

Front 35

What syndrome does PICA occlusion cause?

Back 35

Lateral medullary syndrome

Front 36

What are the sensosry and motor deficits of Lateral Medullary syndrome?

Back 36

(LOSS OF PICA)

SENSORY:
1) DC/ML is spared--it is medial here
2) contralateral loss of pain and temp sensation in body (hit the spinothalamic tract
3) Spinal trigem tract/nucleus is hit. IPSILATERAL loss of sensation in face PAIN AND TEMP.
4) Chief nucleus of trigem is in pons, so OK here.

MOTOR:
1) Corticspinal: ventral/medial and covered by paramedian of basilar. OK.
2) Corticobulbar: bilateral inneraation to most, so OK. Below facial nucleus, so OK for voluntary face movements.

BUT: takes out MBF (runs near ST, which is taken out laterally.) So IPSILATERAL HORNERS.

Front 37

Unliateral lesion of Internal capsule (MCA?)--motor and sensory defects

Back 37

1) contralateral loss of pain, temp, vibr, fine touch, proprioception in body and face

2) MOTOR: contralateral loss of voluntary movement EXCEPT upper face, which is bilaterally innervated by corticobulbar tracts.

Front 38

Where is abducens nucleus?

Back 38

Midline, pons

Front 39

Where is facial nucleus

Back 39

Pons, In ventral AICA section, not medial but not lateral.