brainstem Flashcards
0
Q
what constitutes the brainstem
A
pons, medulla and mid brain
1
Q
functions of the brainstem (in general)
A
- reflexive and unconscious behaviour
- modulation of various arousal and conscious states
- important in ANS control
- cranial nerves arise from here
2
Q
where does the brainstem extend from/to
A
from the mamillary bodies (rostrally) to the pyramidal decussation (caudally)
3
Q
dorsal and ventral external aspects of the midbrain
A
- dorsal - superior and inferior colliculi
- ventral - cerebral peduncles with interpenduncular fossa
4
Q
what forms the facial colliculi
A
the abducens nucleus and the fibres of cranial nerve 8 (facial nerve)
5
Q
dorsal and ventral external aspects of the pons
A
- dorsal - facial colliculi
- ventral - cerebellar peduncles
6
Q
dorsal and ventral external aspects of the medulla
A
- dorsal –> caudally there are dorsal columns and nuclei - gracile and cuneate tubercle
- ventral –>rostrally - inferior olivary nuclei, caudally - pyramidal decussation
7
Q
what is the tegmentum
A
that part of the brainstem that is continuous with the spinal cord
8
Q
what is the tectum
A
the superior and inferior colliculi of the midbrain
9
Q
what is contained in the tegmentum
A
the cranial nerves and the reticular formation
10
Q
what is contained in the basis of the brainstem
A
decending motor fibres and things that help control it
11
Q
function of the cranial nerves
A
supply somatic and visceral motor and sensory information to the head
12
Q
which cranial nerve does not exit the brainstem ventrally
A
CN IV
13
Q
which cranial nerves are exclusively motor
A
3, 4 and 6 - control eye movements
11 and 12
14
Q
which cranial nerves are exclusively sensory
A
1, 2 and 8 - smell, sight and balance
15
Q
which cranial nerves are mixed nerves
A
5, 7, 9 and 10
16
Q
what is the rule of 4 for cranial nerves
A
4 cranial nerves exit the medulla (9-12)
4 cranial nerves exit the pons (5-8)
4 cranial nerves exit above the pons (1-4)
17
Q
what arrives from the alar plate and basal plate developmentally
A
alar plate - sensory nuclei
basal plate - motor nuclei
18
Q
what is the positioning of the motor and sensory nerves in the brainstem
A
motor - closer to the midline
sensory - more laterally
19
Q
what are the 3 motor columns within the brainstem
A
general somatic motor
brachial motor
general visceral
20
Q
what are the 3 sensory columns within the brainstem
A
general and special visceral
general somatic
special somatic
21
Q
what is the reticular formation
A
a network of scattered cell bodies throughout the dorsal brainstem (like a spread out nuclei)
22
Q
the reticular formation is continuous with…
A
- certain nuclei in the thalamus
- intermediate grey of the spinal cord
23
Q
basic function of the rostral reticular formation (in midbrain and upper pons)
A
maintain alert conscious state
24
basic function of caudal brainstem (pons and medulla)
do things similar to the spinal cord - survival reflexes
| variety of important motor reflex and autonomic functions
25
what are the 4 projection systems of the ascending reticular activating system and where are they
noradrenergic - locus ceruleus
dopaminergic - substantia nigra
serotonergic - dorsal raphe
cholinergic
26
what is the function of the ventrolateral medullary reticular formation
regulates the visceral functions of the vagus nerve
(GI - swallowing, vomiting
respiratory - rhythm, coughing, hiccupping, sneezing
cardiovascualr)
27
3 major long fibre tracts through the brainstem
dorsal column-medial lemniscus system
anterolateral system
corticospinal system
28
where does the corticospinal tract decussate
at the pyramidal decussation
29
which structures are associated with the basis (ventral) part of the midbrain, pons and medulla
midbrain - cerebral peduncles, substantia nigra, red nuclei
pons - CB nuclei, middle cerebellar peduncle
medulla - inferior olivary nuclei
30
explain the orientation and anatomy of the columns through the spinal cord
3 sensory columns - lateral
| 3 motor columns - medial
31
What are the 12 cranial nerves
```
olfactory
optic
occulomotor
trochlear
trigeminal
Abducent
Facial
Vesticulocochlear
Glossopharyngeal
Vagus
Accessory spinal
Hypoglossal
```
32
What are the foramina associated with the first 4 cranial nerves
```
olfactory = cribiform plate
optic = optic canal
occulomotor = superior orbital fissure
Trochlear = superior orbital fissure
```
33
what are the foramina associated with the trigeminal nerve
orbital branch = superior orbital fissure
maxillary branch = formaen rotundum
mandibular branch = formamen ovale
34
what is the foramina associated with cranial nerves 6-12
abducent = superior orbital fissure
facial = internal acoustic meatus --> stylomastoid foramen
vestibulocochlear = internal acoustic meatus
glossopharyngeal, vagus and accessory = jugular foramen
hypoglossal = hypoglossal canal
35
which brainstem "column/s" is the olfactory nerve associated with?
special sensory column
36
which brainstem "column/s" is the optic nerve associated with?
special sensory column
37
which brainstem "column/s" is the occulomotor nerve associated with?
somatic motor column
and
visceral efferent column - Edinger-Westfal nucleus
38
which brainstem "column/s" is the trochlear nerve associated with
somatic motor column
39
which brainstem "column/s" is the trigeminal nerve associated with?
mandibular branch - branchial arch column
and
somatic sensory column
40
which brainstem "column/s" is the abducent nerve associated with?
somatic motor column
41
which brainstem "column/s" is the facial nerve associated with?
brachial arch column
and
visceral efferent column - superior salivatory nucleus
and
visceral afferent column - gustatory nucleus of the nucleus solitarius
and
somatic sensory column
42
which brainstem "column/s" is the vestibulocochlear nerve associated with?
special sensory column - dorsal and ventral cochlear nuclei and 4 vestibular nuclei
43
which brainstem "column/s" is the glossopharyngeal nerve associated with?
branchial arch column- nucleus ambiguus-stylopharyngeus
and
visceral efferent column - inferior salivatory nuleus
visceral afferent column - gustatory nucleus of nucleus solitarius
and
somatic sensory column
44
which brainstem "column/s" is the vagus nerve associated with
branchial arch column - nucleus ambiuus-levator palati
and
visceral efferent column - dorsal motor nucleus of the vagus
and visceral afferent - gustatory nucleus of the nucleus solitarius
and
somatic sensory column
45
which brainstem "column/s" is the hypoglossal nerve associated with
somatic motor column
46
which nerves have associated ganglia? and what are they called?
optic nerve = retina
| trigeminal nerve = trigeminal ganglia
47
function/s of olfactory nerve
sense of smell
48
function/s of optic nerve
vision
49
function/s of occulomotor nerve
- innervates superior rectus, medial rectus, inferior rectus and inferior oblique muscles of the eyeball
- elevates eyelid via innervation of levator palpebrae superioris
- controls focussing and pupil constriction
50
function/s of trochlear nerve
innervates superior oblique muscle of the eyeball
51
function/s of the trigeminal nerve
- innervates muscles of mastication
- innervates tensor tympani muscle of the inner ear
- sensory innervation of the face
52
function/s of the abducent nerve
innervates lateral rectus muscle of the eyeball --> abduction of the eyeball
53
function/s of the facial nerve
- innervates the muscles of facial expression
- innervates stapedius muscle of the ear
- innervates part of the digastric muscle
- innervates orbicularis occuli (to close the eye)
- taste from anterior 2/3 of tongue and soft palate
- sensation from small region near the external auditory meatus
- innervation to the lacrimal, sublingual and submandibular salivary glands
54
function/s of the vestibulocochlear nerve
hearing and balance
55
function/s of the glossopharyngeal nerve
- innervates stylopharyngeus muscle for soft palate elevation
- taste from posterior 1/3 of tongue
- sensation from posterior 1/3 of tongue, pharynx, middle ear and carotid body
- PNS innervation to parotid gland
56
function/s of the vagus nerve
MOSTLY AUTONOMIC
- PNS innervation to many organs
- input from baroreceptors and chemoreceptors of the aortic arch
- motor innervation to many striated muscle (including palatoglossus and levator palati)
- sensory from pharynx, larynx and oesophagus
57
function/s of accessory nerve
innervates sternocleidomastoid and the upper part of trapezius to allow shrug of shoulders and turn of the neck
58
function/s of the hypoglossal nerve
innervation to the intrinsic and extrinsic muscles of the tongue (except palatoglossus)
59
which nerves provide innervation to places other than the face and head
glossopharyngeal (IX) and vagus (X)
60
which nerves do not originate in the brainstem
spinal accessory nerve
61
explain the order of the 3 motor columns in the brainstem (in reference to the midline)
somatic motor - most medial
branchial motor - middle
visceral motor - most lateral
62
which cranial nerves have their nuclei in the somatic motor column
3, 4, 6 = eyeball movement
| 12 = tongue
63
which cranial nerves have their nuclei in the branchial arch column
5 = mastication
7 = facial muscles for expression
9 + 10 = muscles for pharynx and larynx
64
what is the nucleus ambiguus?
motor nucleus associated with cranial nerves IX and X
65
what are the two parts of the nucleus ambiguus associated with cranial nerves IX and X
```
IX = motor innervation to stylopharyngeus
X = motor innervation to levator palati
```
66
which cranial nerve is the Edinger Westfal nucleus associated with
cranial nerve 3 = occulomotor nerve
67
which cranial nerve is the superior salivatory nucleus associated with
cranial nerve 7 = facial nerve
68
which cranial nerve is the dorsal motor nucleus of the vagus associated with
cranial nerve 10 = vagus nerve
69
which cranial nerve is the inferior salivatory nucleus associated with
cranial nerve 9 = glossopharyngeal nerve
70
what are the 4 nuclei in the visceral efferent column in the brainstem
Edinger-Westfal nucleus - III
Superior salivatory nucleus - VII
inferior salivatory nucleus - IX
dorsal motor nucleus of the vagus - X
71
explain the order of the 3 sensory columns in the brainstem (in reference to the midline)
visceral sensory - most medial
somatic sensory - middle
special sensory - most lateral
72
which cranial nerves have their nuclei in the visceral sensory/afferent column of the brainstem?
VII, IX, X - taste
| IX and X - autonomic
73
which nucleus is associated with the visceral sensory/afferent column of the brainstem?
the nucleus solitarius
74
what are the rostral and caudal divisions of the nucleus solitarius
rostral: gustatory nucleus - receives input from VII, IX and X for taste
Caudal: visceral sensory division - receives input from IX (baroreceptors and chemoreceptors from carotid body and sinus) and X (afferents from heart and abdominal viscera)
75
Which cranial nerves have their nuclei in the somatic sensory column of the brainstem?
V - facial sensation
| VII, IX and X - skin behind ear and lining of external auditory meatus
76
Which cranial nerves have their nuclei in the special sensory column of the brainstem?
I - smell
II - vision
VIII - hearing and balance
77
what are the 6 extraoccular muscles
```
superior rectus
inferior rectus
medial rectus
lateral rectus
superior oblique
inferior oblique
```
78
which nerves act together for occular movement
III, IV and VI
79
which nerves pass through the common tendinous ring when passing to the eyes
occulomotor (III) and VI (abducent)
80
which nerves exit the cranium through the superior orbital fissure
III, IV, VI and V1
81
which nerves exit the cranium through the auditory canal
VII and VIII
82
which nerves exit the cranium through the jugular foramen
IX, X, and XI
83
what are the 3 main reflexes to test brainstem function
pupillary light reflex
sensory reflex
gag reflex
84
which nerves are you testing in the pupillary light reflex
II (sensory arm of reflex)
| III (motor arm)
85
3 sensory branches of the trigeminal nere
orbital (V1)
maxillary (V2)
mandibular (V3)
86
what are the 4 nuclei contained within the trigeminal nucleus
chief sensory nucleus
mesencephalic nucleus
spinal trigeminal nucleus
motor nucleus
87
which nuclei of the trigeminal nucleus are like the dorsal ganglia of the dorsal column in the anterolateral system
the chief sensory nucleus and the spinal trigeminal nucleus
88
with what other structure does the motor root of the trigeminal nerve travel with
the mandibular division of the sensory root of the trigeminal nerve
89
which cranial nerves are you testing with the corneal blink reflex
V1 - trigeminal - opthalmic branch - (sensory)
| VII - facial - (motor)
90
what is the corneal blink reflex testing (generally)
pontine function
91
2 branches of the facial nerve
facial nerve proper (branchial motor)
| nervus intermedius
92
what are the 6 terminal branches of the facial nerve
```
posterior auricular
temporal
zygomatic
buccal
mandibular
cervical
```
93
which gland does the facial nerve pass through but not innervate
the parotid gland
94
which nerve innervates the parotid gland
glossopharyngeal nerve (PNS)
95
what is the function of stylopharyngeus muscle
allows our palate to elevate while we talk
96
what is the pathway of the glossopharyngeal nerve
exits the skull via the jugular foramen --> follows the stylopharyngeus to reach the oropharynx and the tongue
97
which nerves innervate the pharynx and larynx
vagus (motor and sensory) and glossopharyngeal (sensory)
98
what is the gag reflex used to test (in general)
test of medulla function
99
what cranial nerves are being tested with the gag reflex
IX (sensory)
| X (motor)
100
pathway of the spinal accessory nerve
ENTERS the cranium via the foramen magnum
| then travels with X roots and exits via the jugular foramen
101
which nuclei can receive input or provide efferent output to more than one cranial nerve
nucleus solitarius
nucleus ambiguus
trigeminal nucleus
