Brainstem

Question 1

what are the 3 parts of the brainstem?

Answer 1

1. midbrain.
2. pons.
3. medulla oblongata.

Question 2

what is the function of the brainstem?

Answer 2

to serve as a conduit for ascending and descending tracts.

to contain important reflex centres and the 12 cranial nerves.

the brainstem controls important automatic, involuntary reactions.

Question 3

what does the brainstem connect?

Answer 3

the spinal cord to the brain.

Question 4

what are the pyramidal tracts?

why are they named so?

Answer 4

the pyramidal tracts are the corticospinal and the corticobulbar tracts.

they are named as pyramidal tracts as they pass through the pyramids of the medulla.

Question 5

what are the 3 types of cerebellar peduncles called?

Answer 5

1. superior.
2. middle.
3. inferior.

Question 6

where does corticospinal tract originate and terminate?

Answer 6

in the primary motor cortex (part of cerebral cortex) and the spinal cord.

Question 7

where does the corticobulbar tract originate and terminate?

Answer 7

in the primary motor cortex and the medulla.

Question 8

why does the cbulbar tract terminate earlier than the cspinal?

Answer 8

as the cbulbar controls muscles of the head and neck, therefore, the UMNs synapse with LMNs in various brainstem nuclei and cranial nerves.

Basically, they innervate the CNs so can stop once they have reached them.

Question 9

what does the corticospinal tract control?

Answer 9

fine motor, skilled movements and execution of voluntary movement.

Question 10

what does the corticobulbar tract control?

Answer 10

controls muscles of the head and face therefore facial expression, speech, and swallowing.

Question 11

which 2 tracts run parallel and very closely to each other?

Answer 11

cbulbar and cspinal.

Question 12

what does an ascending pathway refer to?

Answer 12

neural pathways in which info is sent from peripheral nerves to the cortex to the brain.

so from receptors to the brain.

Question 13

what does the spinothalamic tract transmit info about?

Answer 13

pain, temp and light touch.

Question 14

the spinothalamic tract is a part of what system?

Answer 14

anterolateral.

Question 15

where does the spinothalamic tract originate and terminate?

Answer 15

it originates in nociceptors and terminates in the primary somatosensory cortex of the brain.

Question 16

what is the second name for the dorsal column pathway?

Answer 16

the medial lemniscus pathway.

Question 17

what info does the dorsal column pathway carry?

Answer 17

transmits info about fine touch, proprioception and vibration.

Question 18

where does the dorsal column pathway originate and terminate?

Answer 18

it originates in cutaneous receptors and terminates in the primary somatosensory cortex of the postcentral gyrus.

Question 19

name the components of the midbrain: (7)

Answer 19

tectum,
substantia nigra,
crus cerebri,
tegmentum,
cerebral aqueduct,
cerebral peduncle,
superior and inferior colliculi.

Question 20

which 2 components of the midbrain make up the cerebral peduncles?

Answer 20

crus cerebri,
tegmentum.

Question 21

which pathways are the superior and inferior colliculi’s respectively a part of?

Answer 21

superior = visual.

inferior = auditory.

Question 22

what is the tectum?

Answer 22

the dorsal part of the midbrain.

Question 23

what is the tegmentum?

Answer 23

the ventral part of the midbrain.

Question 24

what is the substantia nigra?

Answer 24

a part of the midbrain and the basal ganglia that is important in reward and movement. it contains melanin, making it a dark colour.

Question 25

what is the reticular formation?

Answer 25

a network of nerve pathways in the brainstem connecting the spinal cord, cerebrur and cerebellum.

it controls consciousness.

Question 26

what are the 3 major nuclei of the reticular formation?

Answer 26

1. raphe nuclei
2. cholinergic reticular nuclei.
3. noradrenergic neurons.

Question 27

what is the raphe nuclei?

Answer 27

groups of neurones either in or adjacent to the midline of the brainstem.

Question 28

what does the raphe nuclei do?

Answer 28

they synthesise and secrete serotonin.

Question 29

when are raphe nuclei active?

Answer 29

in deep sleep.

Question 30

what areas of the CNS to raphe nuclei project to?

Answer 30

spinal cord, brainstem, cerebellum, thalamus and cortex.

Question 31

where are cholinergic reticular nuclei found?

Answer 31

in the pons and midbrain region.

Question 32

when are cholinergic reticular nuclei active?

Answer 32

in awake state

Question 33

where are noradrenergic neurons found?

Answer 33

in locus coeruleus.

Question 34

when are noradrenergic neurons active?

Answer 34

in the awake state.

Question 35

what do noradrenergic neurons regulate?

Answer 35

arousal and attention.

Question 36

the reticular formation controls what?

Answer 36

• skeletal muscles.
• somatic and visceral sensations.
• ANS.
• endocrine NS.
• sleep, arousal and consciousness.
• pain modulation

Question 37

why does a stroke occur?

Answer 37

when blood supply to the brain is cut off.

Question 38

what are the 2 types of strokes?

Answer 38

1. ischaemic
2. haemorrhaegic

Question 39

why does an ischaemic stroke occur?

Answer 39

because of inadequate blood supply. usually caused by blockage in the vessel.

Question 40

why does a haemorrhagic stroke occur?

Answer 40

it’s caused by a rupture of blood vessels.