Brainstem Overview and Cranial Nerve Nuclei Flashcards

1
Q

What is the brainstem

A
  • Part of brain lying between spinal cord, cerebellum and cerebral hemisphere
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What makes up the brainstem?

A
  • medulla
  • pons
  • midbrain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the main brainstem structures?

A
  • Nuclei for 10 of 12 pairs of cranial nerves
  • Controls eye movements (3rd, 4th and 6th Cranial nerves
  • Areas vital in the control of respiratory and cardiovascular systems
  • Autonomics nervous system nuclei
  • Several ascending and descending tracts connecting spinal cord to cerebral cortex and cerebellum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the position of grey matter in the spinal cord vs the brainstem

A

Spinal cord = more vertical

Brain stem = more horizontal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 7 main afferent input and efferent output pathways and their positioning in the brainstem?

A
  • Special sensory afferent (SSA)
  • General sensory afferent (GSA)
  • General visceral afferent (GVA)
  • Special visceral afferent (SVA)
  • General visceral efferent (GVE)
  • Special visceral efferent (SVE)
  • General somatic efferent (GSE)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the arrangement of function in the brainstem of:

GSE

A
  • GSE (somatic motor)
    • Hypoglossal nucleus – innervates tongue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the arrangement of function in the brainstem of:

SVE

A
  • SVE (visceral motor)
    • Nucleus ambiguous
      • Swallowing, speech, heart rate control
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the arrangement of function in the brainstem of:

GVE

A
  • GVE (autonomic motor)
    • Dorsal motor nucleus of the vagus (CN X)
      • GI and respiratory control
    • Inferior salivatory nucleus (CN IX)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the arrangement of function in the brainstem of:

GVA

A
  • Solitary nucleus
    • cardiovascular and respiratory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the arranagement of function in the brainstem of:

SVA

A
  • Solitary nucleus
    • Taste
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the arranagement of function in the brainstem of:

GSA and SSA

A
  • GSA and SSA (somatic sensory)
    • Spinal nucleus
    • Vestibular nuclei
    • Vestibular nuclei
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the three major tracts of the medulla?

A
  • Corticospinal tract
  • Medial meniscus
  • Medial longitudnal fasiculus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Desribe the corticospinal tract in the brainstem

A
  • Tract decussates just below the pyramids
  • Controls voluntary movement
  • Brainstem lesion leads to contralateral UMN paralysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the medial meniscus pathway in the medulla

A
  • Originates from dorsal column nuclei
  • Transmit information on about conscious proprioception and vibratory stimuli to thalamus
  • Brainstem lesion leads to contralateral loss of joint proprioception
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the medial longitudnal fasiciculus in the medulla

A
  • Ascending tracts originate from lateral, medial & superior vestibular nuclei and project to pons
  • Information about head position sent to cranial nerves
  • Descending fibres originate from medial vestibular nuclei and project to cervical spinal cord (vestibulospinal tract)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the major nuclei of the medulla?

A
  • Reticular Formation
  • Nucleus gracilis and cuneatus
  • Spinal nucleus of CN V
  • Cochlear, Vestibular nuclei
  • Motor nuclei
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the function of the reticular formation in the medulla?

A
  • Modulation of sensory transmission to cortex
  • Regulation of motor activity
  • Autonomic regulation
  • Sleep wake cycle/emotional behaviour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the function of the nucleus gracilis and cuneatus in the medulla?

A
  • Receive information from dorsal columns
  • Transmit information on conscious proprioception and vibratory stimuli to thalamus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the function of the spinal nucleus of CN V?

A

pain and temperature information from the head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the motor nuclei of the medulla?

A

hypoglossal

nucleus ambiguous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the main attachments of the pons?

A
  • Connection between medulla and midbrain
  • Main attachment of cerebellum
22
Q

What are the two regions of the pons?

A
  • Basilar pons (ventral)
  • Tegmentum
23
Q

What are the ascending tracts of the pons?

A
  • Medical lemniscus
  • Medial longitudinal fasciculus
  • Spinothalamic
  • Trigeminothalamic
24
Q

What are the descending tracts of the pons?

A
  • Corticospinal
  • Corticobulbar
  • Rubrospinal
  • Tectospinal
25
Q

What 4 cranial nerves emerge at the level of the pons?

A
  • trigeminal
  • abducens
  • facial
  • vastibulcochlear
26
Q

What are the main nuclei of the lower (caudal pons)

A
  • Abducens Nucleus (CN VI)
  • Facial Nucleus (CN VII)
  • Vestibular Nuclei
  • Olivary Nucleus
  • Salivatory Nucleus
27
Q

What are the main nuclei of the upper (rostral) pons?

A
  • Main Sensory (trigeminal) Nucleus (CN V)
  • Motor Nucleus (CN V)
  • Nucleus locus ceruleus
  • Mesencephalic Nucleus
28
Q

What is the function of the abducens nucleus?

A
  • Innervates lateral rectus muscle of eye (side to side movement)
29
Q

What is the function of the facial nucleus of the pons?

A
  • Innervate muscles controlling ipsilateral facial expression
30
Q

What is the function of the vestibular nucleus in the Pons?

A
  • Inputs from vestibular apparatus
  • Facilitate extensor motor neurons
31
Q

What is the function of the olivary nucleus in the pons

A
  • Input from cochlear nuclei
  • Transmit auditory signals to higher areas of brainstem
32
Q

What is the function of the salivartory nucleus in the pons?

A
  • Salivation reflex
33
Q

What is the function of the main sensory (trigeminal) nucleus in the pons?

A
  • Transmission of somatosensory information from head region to thalamus
34
Q

What is the function of the motor nucleus (CN V) in the pons

A
  • Innervate muscles controlling mastication
35
Q

What is the function of nucleus locus ceruleus in the pons?

A
  • Projects to cerebral cortex and cerebellum
36
Q

What is the function of the mesencephalic nucleus in the pons?

A
  • Muscle spindle afferent form the jaw
  • Part of reflex jaw closing circuit
37
Q

Where is the midbrain located?

A
  • Lies between pons and forebrain
38
Q

What are the major tracts and nuclei of the midbrain?

A
  • Inferior Colliculus (IC)
  • Superior Colliculus (SC)
  • Red Nucleus (RN)
  • Substantia nigra (SN)
39
Q

Highlight where each of the cranial nerves emerge from the brainstem and give their functions

A
40
Q

What do brainstem lesions usually produce?

A
  • A brainstem lesion will usually produce ipsilateral cranial nerve defects
41
Q

What is the function of PSNS nerves in the pupillary light reflex?

A
42
Q

What is the function of SNS nerves in the pupillary light reflex?

A
  • Radial fibres of iris that dilate pupil and several extraocular muscles of eyes
43
Q

What happens when light is shone into the eyes?

A

the pupil constricts

44
Q

What happens when there is a light stimulation of the retina?

A
  • stimulates optic nerve fibres that innervate pretectal nuclei
  • Secondary impulses pass to Edinger-Westphal nucleus and back through parasympathetic nerves to constrict sphincter of iris
45
Q

Summarise the main contents of the medulla oblongata in the brainstem

A

The caudal medulla contains the pyramids anteriorly (overlying the descending corticospinal and corticobulbar tracts) and the posterior columns posteriorly (overlying the ascending fasciculi gracilis and cuneatus). The rostral medulla contains the pyramids anteriorly, the olives laterally (overlying the inferior olivary nuclear complex), and the caudal part of the fourth ventricle and the inferior cerebellar peduncles posteriorly.

46
Q

Summarise the main contents of the pons in the brainstem

A

The anterior, basal pons contains the transverse pontine fibres and the descending corticospinal and corticobulbar tracts. The fourth ventricle, middle cerebellar peduncles, and superior cerebellar peduncles comprise the posterior pons.

47
Q

Summarise the contents of the midbrain in the brainstem

A

The cerebral peduncles form the anterior part of the midbrain. These contain the descending corticospinal and corticobulbar tracts. The inferior and superior colliculi mark the posterior surface of the caudal and rostral midbrain, respectively, and the cerebral aqueduct lies deep to the colliculi, connecting the third and fourth ventricles.

48
Q

What are the main special senses

A
  • olfaction, vision, taste, hearing and balance
49
Q

What cranial nerves are purely sensory?

A
  • I - olfactory
  • II - optic
  • VIII - vestibulocochlear
50
Q

What cranial nerves are purely motor?

A
  • III - oculomotor
  • IV - trochlear
  • VI - abducent
  • XI - accessory
  • XII - hypoglossal
51
Q

What cranial nerves contain motor and sensory componentd?

A
  • V - trigeminal
  • VII - facial
  • IX - glossopharyngeal
  • X - vagus