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Jonathan's Neuroscience > Brainstem > Flashcards

Flashcards in Brainstem Deck (33):
1

What are the functions of brainstem?

reflexive and unconscious behaviour (for survival)
modulation of various arousal and conscious states

2

What are the components of brainstem?

mid brain, pons, medulla, oblongata

3

Where is the brainstem located? How far does it extend?

in the posterior cranial fossa

extends from Mammillary bodies to the pyramidal decussation

4

What are the surface structures of midbrain, both anteriorly and posteriorly

anterior: cerebral peduncles (contains pyramidal tracts from cortex)

posterior: superior and inferior pairs of colliculi (for eye movement control and hearing)

5

Where is the connection between cerebellum to brainstem?

Pons, via cerebellar peduncles

6

where is the facial colliculi? what are they formed by?

along the floor of the 4th ventricle, between pons and cerebellum

formed by abducens nucleus and fibres of CNVII

7

What's located on the dorsal aspect of medulla?

dorsal columns and nuclei-gracile and cuneate tubercle

8

what's located on the ventral aspect of medulla?

two bulges of inferior olivary nuclei (superior) and pyramidal decussation (posterior)

9

Where is the tectum?

the roof of the midbrain

10

where is the tegmentum

ventral to the ventricular system, running all the way from brainstem to the spinal cord

11

What does the tegmentum cover?

cranial nerves, reticular formation

12

What is the midbrain important for?

it contains important descending motor tracts (corticospinal)
it has a range of nuclei modulating the descending motor fibres

13

What are the pathology associated with midbrain damage both 1) ventrally 2) dorsally

1) tectum and tegmentum are located ventrally, damage can cause major problem with movement

2) cranial nuclei are located dorsally, so damage will cause cranial nerve deficit

14

Do cranial nerves exit the brainstem in order?

Yes, CNIII most rostrally, CNXII most caudally

15

which cranial nerves are mix nerves

trigeminal, facial, glossopharyngeal, vagus

16

which CNs exit the medulla?

glossopharyngeal, vagus, accessory, hypoglossal

17

which CNs exit the pons?

trigem, abducent, facial, vestibulocochlear

18

which CNs exit above the pons?

olfactory, optic, oculomotor, trochlear

19

Embryologically, where are 1) motor nuclei 2) sensory nuclei developed?

1) basal plate
2) Alar plate

20

Which embryological plate shifts laterally? Why does it shift?

alar plate
because the ventricles are in the way

21

How are nuclei of the CN placed in the brainstem?

in columns

22

What is the significance of alar plate shift?

CN sensory nuclei are positioned laterally, whereas motor nuclei are towards the midline

23

What are the three types of brainstem motor nuclei?

general somatic motor
branchial motor
general visceral

24

What happens when the inferior cerebral peduncle is damaged?

peduncle contains projection to cerebellum, so any damage can lead to ataxia (clumsiness)

25

What are the three types of brainstem sensory nuclei?

general sensory
visceral sensory
special sensory

26

Which CN nuclei are located in the midbrain?

oculomotor and trochlea
they are both pure motor nerves, so are located medially

27

Where can you find reticular formation?

within the tegmentum, which extends rostrally with thalamus, through the brainstem, and continuous with gray of spinal cord

28

What is the function of reticular formation rostrally

in the midbrain and upper pons, they maintain alert conscious state

29

What is the function of reticular formation caudally

working with CN and spinal cord to carry out survival reflex like breathing and control of heart rate

30

How does the reticular formation modulate the forebrain?

the rostral RF provides long ascending tracts that release different neurotransmitters to modulate the forebrain

31

What is the function of ventrolateral medullary reticular formation (VMRF)

regulate vagus functions such as GI response (swallowing, vomiting), respiratory activities, CV response

32

What are the three long fibre tracts?

dorsal column medial leminiscus system
anterolateral system
corticospinal tract

33

Where do the three long fibre tracts decussate?

dorsal column - dorsal medulla
anterolateral system - spinal cord
corticospinal tract - pyramidal decussation at ventral oblongata