org. of brainstem

Question 1

____________ : all the ascending and descending pathway fibres have to pass through here to get to the brain

Answer 1

Conduit

Question 2

Cranial Nerves ____ and ____ are not attached to brainstem

Answer 2

1 and 2

Question 3

one function of brianstem is ____________

Answer 3

Integration : respiration , cardiaovascular, control, consciousness, sleep (reticular functions)

Question 4

There are 3 subdivisions of brainstem ______ , __________ and _________

Answer 4

3 main subdivisions of brainstem:

Midbrain (rostral and caudal)

pons “bridge” (rostral and caudal)

Medulla (rostral and caudal)

Question 5

Medulla has two subdivions :

____ and ____

Answer 5

Medulla (rostral and caudal):

• caudal is “closed” and only flows with spinal cord, rostral end is “open to fourth ventricle”
• Obex - where 4th ventricle becomes continues with central canal (a “V”)

Question 6

the ___________ contains the pyramids together with part of the central canal. in its caudal half and part of the fourth ventricle in its rostral half.

Answer 6

medulla

Question 7

the________ contains the basal pons and part of fourth ventricle but only the caudal pons is physically attached too the cerebellum

Answer 7

pons

Question 8

the_________ contains cerebral peduncles and cerebral aqueduct and superior and inferior Colliculi

Answer 8

midbrain

Question 9

_________ on posterior side of mid brain, _______ in middle and _________ on anterior side.

Answer 9

Tectum , tegmentum, cerebral peduncles

Question 10

In the pons no _______ , _______ now posterior side, and pons is anterior “appendage”

Answer 10

tectum, tegmentum

Question 11

____________ still the posterior side in medulla , pons is gone, the ______ are anterior side with the _________

Answer 11

tegmentum , pyramids , olives

Question 12

Define the 3 major pathways and their functions

Answer 12

Corticospinal tract (voluntary movement)

Spinothalamic tract (pain and temperature)

Posterior columns (touch sensation and proprioception)

Question 13

-__________ descends from motor strip down to spinal cord (on anterior side of brain stem). Through the _______ , _____ , and ______ , the fibers cross at the ________ and head down the spinal cord as the lateral __________ .

Answer 13

Corticospinal tract (voluntary movement) - descends from motor strip down to spinal cord (on anterior side of brain stem). Through the internal capsular cerebral peduncles, basal pons, and pyramids, the fibers cross at the spinomedullary junction and head down the spinal cord as the lateral corticospinal tracts.

Question 14

_____________ - ascends from spinal cord up through brainstem to the thalamus (on anterior lateral side of Tegmentum)

Answer 14

Spinothalamic tract (pain and temperature)

Question 15

_____________ - ascend the posterior spinal cord and end in the medulla (in the gracilis nucleus and the cuneatus nucleus) to become medial lemniscus which ascends to the thalamus.

Answer 15

Posterior columns (touch sensation and proprioception)

Question 16

Define gneral features of Caudal Medulla

Answer 16

1- Caudal Medulla (Closed end)

end of spinal cord.

from cuneatus and gracilis nucleus fibers cross the midline and form the contralateral medial lemniscus (this is the sensory crossing)

spinothalamic tract in the tegmentum

Pyramid append off the anterior side,

Reticular formation in the center.

Question 17

Define the general features of Rostral Medulla

Answer 17

2. Rostral Medulla (open end)

section from obex to cerebellar peduncles

contains the inferior olivary nucleus and part of Forth Ventricle

Question 18

Define general features of Caudal Pons

Answer 18

Caudal Pons

Physically connected to the cerebellum btw the cerebellar peduncles

Inferior olivary nucleus ends medial lemniscus still here,

lots of fibers here (pyramidal tract, spinothalamic, CST .. )

Fibers originate and go to cortex

Pons is bridge (to Cb, from brain to spinal cord, left/right crossings)

Question 19

Define general features of Rostral pons

Answer 19

Rostral pons

• Not directly connected to Cb, still touches 4th ventricle, cerebral aquaduct.
• Pons has several nuclei and crossing tracts, major fiber crossing center (like CC)

Question 20

Define general features of Caudal Midbrain

Answer 20

Caudal Midbrain

Tectum = superior and inferior colliculi

caudal midbrain contains inferior collicuulo (auditory)

superior cerebellar peduncles cross here

periaquaductal gray begins (pain control)

pons is gone now and instead is cerebral peduncles (where the CST travels)

Question 21

Define general features of Rostral midbrain

Answer 21

Rostral midbrain

contains superior colliculi (vision)

red nucleus and substantia nigra (important brainstem nuclei)

thalamus and spinal glad are nearby

Question 22

______________ : Not so much a structure but a collection of connections that meme the core of the brainstem

Answer 22

Reticular formation

Question 23

what are the three major zones of Reticular formation

Answer 23

Three major zones :

Raphe nuclei (“seam” on midline)

Gigantocellular reticular nucleus (or medial zone)

Lateral zone (reflexes and visceral functions)

Question 24

Reticular formation has two reticulospinal tracts:

1- ___________. - (orientation ? )

2- ___________ - (orientation ?)

Answer 24

1- pontine reticularspional tract. - medial

2- medullary reticuspino reat - lateral

Question 25

______________ help control motor system especially motor reflexes that do not have to travel to cortex and makes sure only noxious stimuli can cause a reflex (hand in fire)

Answer 25

Reticular formation

Question 26

___________ can also modulates pain.

• internal pain suppression mechanism

stimulation of ______________ is powerful analgesic

stimulation can treat otherwise intractable pain

___________ (and other opiates) work by stimulation the ____________ ….

Answer 26

Reticular formation : modulates pain

internal pain suppression mechanism

stimulation of periaquaductal gray is powerful analgesic

stimulation can treat otherwise intractable pain

morphine (and other opiates) work by stimulation the periaquaductal gray ….

Question 27

_______________ serve Visceral reflexes : autonomic control of breathing , heart rate, blood pressure.

Answer 27

Reticular formation : Visceral reflexes

autonomic control of breathing , heart rate, blood pressure.

Question 28

______________ also serves in sleep and consciousness , arousal / attention

the part of RF involved in this is the __________________

damage to ARAS induces ____________

ARAS can also regulate _________________

also involved in ______________.

Answer 28

Reticular formation : sleep and consciousness , arousal / attention

the part of RF involved in this is the ARAS (ascending reticular activating system)

damage to ARAS induces coma

ARAS can also regulate sleep-wake cycle

also involved in arousal/attention.

Question 29

______________ are the base of most Neurotransmitter system

especially the __________ NTs ( norephin … dopamine, sera ) and ________

____________ also produces in the brain stem

Answer 29

Brainstem nuclei are the base of most NT system

especially the biogenic amine NTs ( norephin … dopamine, sera ) and histamines

aceylochlione also produces in the brain stem

Question 30

_____________ neurons only found in pons and medulla.

• most of locus ceruleus “blue spots” (in rostral pons) - theses neurons go to the cortex
• some in medullary reticular formation - these go to spinal cord.

may play a role in vigilance …

Answer 30

norepinephrine neurons only found in pons and medulla.

most of locus ceruleus “blue spots” (in rostral pons) - theses neurons go to the cortex

some in medullary reticular formation - these go to spinal cord.

may play a role in vigilance …

Question 31

_______ neurons in ________ and ________ , _______ projects to frontal and limbic cortex (mesocortical and mesolimbic fibers)

SN has two parts: ________ and _________

SN projects fibers to the caudate/putamen (stratum) called __________

DA in PEC controles ___________

Answer 31

DA neurons in substtantia nigra and ventral tegmental area (VTA ) , VTA projects to frontal and limbic cortex (mesocortical and mesolimbic fibers)

SN has two parts: pars compacta and parts reticularis

SN projects fibers to the caudate/putamen (stratum) called nigrotrital fibers

DA in PEC controles motor initiation. . DA in limbic … etc

etc

Question 32

Raphi nucleus - seratonin

seratonin neurons are concentrated in the _________ and project widely across the whole brain

____________ project to forebran and concentrate on limbic and sensory areas

____________ project to Cb, brainstem, spinal cord

Firing rates fluctuate with sleep/wake so likely help regulate arousal , likely the level of “depression” …

Answer 32

Raphi nucleus - seratonin

seratonin neurons are concentrated in the raphi nucleus and project widely across the whole brain

rostral raphi nuclei project to forebran and concentrate on limbuc and sensory areas

caudal raphi nuclei project to Cb, brainstem, spinal cord

Firing rates fluctuate with sleep/wake so likely help regulate arousal , likely the level of “depression” …

Question 33

rostral brainstem and basal formation - acetycholine

Ach is widespread an ______________

CNS (muscarinic) more focal : in _______ and __________ (nucleus basalis , septal nuclei, substantia innominata) some in caudata and putamen.

__________ system implicated in Alzherinemr’s , sleep/wakem and learning / memory.

Answer 33

rostral brainstem and basal formation - acetycholine

Ach is widespread an PNS motor system (nicotinic)

CNS (muscarinic) more focal : in retucular formation and basal forebrain (nucleus basalis , septal nuclei, substantia innominata) some in caudata and putamen.

Basal froebrain cholineregic system implicated in Alzherinemr’s , sleep/wakem and learning / memory.

Question 34

Brainstem Blood Supply

perfused by the _____________

gives rise to _____________ (wraps around brainstem)

midbrain also supplied by PCA gives territories that generally map onto brainstem stroke locations.

Answer 34

Brainstem Blood Supply

perfused by the vertebral-basilar artery system

gives rise to circumferential artery system (wraps around brainstem)

midbrain also supplied by PCA gives territories that generally map onto brainstem stroke locations.