Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MBBS II HNNS > L04 - Brainstem > Flashcards

L04 - Brainstem Flashcards

1
Q

What are the boundaries of the brainstem (anterior and posterior)

A

Anterior = Optic tract (sup.), C1 spinal nerve (inf.)

Posterior = Superior colliculus (sup.), C1 spinal nerve (inf.)

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

3 major functions of the brainstem.

A

1) Passed through by all ascending, descending pathways
2) Where nuclei of most cranial nerve are located (e.g. 5 senses, facial expression)
3) Where many important life centers (reticular formation) are located, e.g. heartbeat, breath, blood pressure, ascending activating system, blood pH

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

What are the main regions of the brainstem

A

Diencephalon

Midbrain

Pons

Medulla oblongata

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

List some major external structures of Diencephalon.

A

Thalamus

Lateral and Medial geniculate body

Pineal gland Optic tract

Mammillary body

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

List some major external structures of Midbrain.

A

Superior colliculi + Inferior colliculi = Corpora quadrigemina

Superior and inferior cerebral peduncle

Trochlear nerve

Oculomotor nerve

Interpenducular sulcus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

List some major external structures of Pons.

A

Superior, middle and inferior cerebellar peduncle

Medial eminence

Rhomboid fossa of 4th ventricle

Hypoglossal and Facial trigone

CN V, VII, VIII

Basilar sulcus (ant.) Median sulcus, Stria medullares, Sulcus limitans (post.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

List some major external structures of Medulla oblongata

A

Olive Pyramid (+ decussation of pyramid at inf. border)

Cuneate fasciculus

Gracile fasciculus

CN IX, X, XI, XII

Anterior median fissure

Posterior median fissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List all the cranial nerves found in midbrain.

A

CN 2-4

Optic tract

Oculomotor nerve

Trochlear nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

List all the cranial nerves found in Pons

A

CN 5 - 8

Trigeminal nerve

Facial nerve

Abducens nerve

Vestibulocochlear nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

List all the cranial nerves found in Medulla oblongata

A

CN9 - 12

Glossopharyngeal nerve

Vagus nerve

Accesory nerve

Hypoglossal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which cranial nerve separates midbrain and pons.

A

Oculomotor nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which cranial nerves separate pons and medulla oblongata?

A

CN VI, VII, VIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What pathways go through the medulla oblongata?

A

Dorsal: Dorsal - Medial Lemniscus tract (ascending sensory)

Ventral: Corticospinal tract (descending motor)

Middle: Reticular formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

List the internal structures found at the inferior medulla oblongata.

A

Dorsal:

  • Nucleus Gracilis (lower limb sensory) + fasciculus
  • Nucleus Cuneatus (upper limb sensory) + fasciculus
  • Nucleus of Trigeminal nerve
  • Internal arcuate fibers (decussation for Dorsal Column Medial Lemniscal pathway)

Ventral:

  • Anterior gray column
  • Medullary pyramids + pyramidal decussation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List the internal structures found at the middle medulla oblongata.

A

Dorsal:

  • Nucleus Gracilis. Nucleus Cuneatus
  • Nucleus of trigeminal nerve
  • Nucleus of Hypoglossal nerve

Ventral:

  • Inferior olivary nucleus (hearing)
  • Medial meniscus (relay mechanical sensory info from nucleus gracilis and cuneatus to thalamus)
  • Corticospinal tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

List the internal structures found at the superior medulla oblongata.

A

Dorsal:

  • Vestibular nucleus
  • Vagus nucleus
  • Trigeminal nerve
  • Ambiguus nucleus (IX, X, XI)
  • Inferior cerebellar peduncle
  • Reticular formation (moved from middle to post)
  • Spinothalamic tract (lateral)

Ventral:

  • Medial lemniscus (Dorsal Column Medial Lemniscal pathway)
  • Corticospinal tract
  • Inferior olivary nucleus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

List the internal structures found at inferior pons.

A

Dorsal:

  • Abducens nucleus - Facial nerve
  • Middle cerebellar peduncle
  • Reticular formation
  • Medial lemniscus (DMLT)

Ventral:

  • Corticospinal tract
  • Pontine nucleus >> pontocerebellar fibers >> Middle cerebellar peduncle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

List the internal structures found at superior pons.

A

Dorsal:

  • Superior cerebellar peduncle
  • Medial lemniscus

Lateral: Pontine nucleus

Middle: Trochlear nucleus Reticular formation

Anterior: Corticospinal tract (antero-lateral, scattered between pontocerebellar fibers from pontine nucleus)

19
Q

List the structures found at the midbrain. (Tectum and different areas of Tegmentum)

A

Tectum (dorsal):

  • Superior and inferior colliculus

Tegmentum (posterior):

  • Cerebral aqueduct + Periaqueductal gray
  • Oculomotor nucleus

Tegmentum (middle):

  • Medial lemniscus - Reticular formation - Red nucleus (motor) - Cerebral peduncle

Tegmentum (anterior):

  • Corticospinal tract (lateral) - Oculomotor nerve* (through interpeduncular fossa) - Substantia nigra (controls basal ganglia)
20
Q

Functions of the Medulla Oblongata?

A
  • House discerte nuclei (i.e. CN 5, 9 - 12) in internal gray matter
  • Connect with spinal cord via ascending DCML, spinothalamic and descending corticospinal tracts
  • regulates: heart rate, blood vessel diameter, respiration, swallowing, vomiting, hiccupping, coughing, sneezing
  • Pyramid and Olive functions
21
Q

Function of pyramids in Medulla Oblongata?

A

descending nerve tracts on the anterior surface.

Inferiorly fibers decussate; thus each half of the brain controls the opposite half of the body

22
Q

Function of olives in Medulla Oblongata?

A

rounded; protrude from anterior surface.

regulate balance, coordination, modulation of sound from inner ear

23
Q

Function of Pons?

A
  • Host fiber tracts to connect with cerebellum
  • House Pontine nuclei + Cranial nerve V-IX
  • Sleep and Respiratory center
  • House ascending and descending fibers
24
Q

Function of midbrain tectum?

A

2 superior colliculi involved in visual reflexes (receive information from inferior colliculi, eyes, skin, cerebrum)

2 inferior colliculi involved in hearing

25
Q

Function of midbrain tegmentum?

A

House nerve tracts:

  • Ascending tracts (e.g. spinal and medial lemniscus from spinal cord to brain)
  • Descending: cerebral peduncles from cerebrum through brainstem to spinal cord
26
Q

Function of midbrain red nuclei and substantia nigra?

A

– Red nuclei of tegmentum: aid in unconscious regulation and coordination of motor activities

– Substantia nigra: pigmented with melanin; interconnected with basal nuclei of the cerebrum (motor)

27
Q

Outline the outflow of Corticospinal tract through the brain stem.

A

Motor cortex

>> Cerebral peduncle in midbrain

>> Pyramids in medulla oblongata >> pyramidal decussation

>> Lateral corticospinal tract + Anterior corticospinal tract

28
Q

Define reticular formation.

A

Diffusely interconnected neurons in brainstem (vs. more distinct nuclei associated with cranial nerves)

29
Q

Function of reticular formation?

A
  • INTEGRATE INFO: sensory, visceral, limbic, and motor functions, and project throughout the CNS
  • MODULATE FUNCTIONS: autonomic regulation of vital organ system, behavior, somatic motor activities, sleep cycles, alertness, pain modulation
30
Q

What are the 4 types of reticular formation?

A

Ascending reticular activating system (ARAS):

  • Norepinephrine system
  • Serotonin system
  • Ach system
  • Dopamine system
31
Q

Outline the basic functions of the 4 types of reticular formation?

A
  • Norepinephrine system = Alertness, fight or flight
  • Serotonin system = Mood and emotions
  • Pontine- Ach system = wakefulness
  • Dopamine system = habitual and working memory + incentive emotion
32
Q

Wakefulness is maintained by neuronal activity in which parts of the brain?

A

maintained by cholinergic neuronal activity in 2 main arousal centers (Ach):

  1. Brainstem: supplies acetylcholine for thalamus, brainstem
  2. Forebrain: supplies acetylcholine for cerebral cortex
33
Q

Pathology of Wallenberg syndrome?

A

Occlusion of the posterior inferior cerebellar artery supplying the LATERAL aspect of the medulla

34
Q

What internal structures of the brainstem are affected by Wallenberg syndrome?

A

Affect lateral medulla:

  • CN V, IX, X
  • Spinothalamic tract
  • Ambiguus nucleus
  • Sympathetic nerve
35
Q

Damage to CN V in Wallenberg syndrome causes what symptoms?

A

ipsilateral analgesia, thermoanesthesia

36
Q

Damage to Spinothalamic tract in Wallenberg syndrome causes what symptoms?

A

contralateral analgesia, thermoanesthesia below neck

37
Q

Damage to ambiguus nucleus in Wallenberg syndrome causes what symptoms?

A

ipsilateral paralysis in palatal, laryngeal muscles

38
Q

Damage to sympathetic nerves in Wallenberg syndrome causes what symptoms?

A

Horner’s syndrome

Drooping eyelids, reduced pupil size

39
Q

Pathology of Medial Medullary Syndrome?

A

Occlusion of the branches of vertebral artery supplying the MEDIAL aspect of the medulla

40
Q

What internal structures are affected in Medial Medullary Syndrome?

A
  • Medial lemniscus
  • Corticospinal tract
  • CN XII
41
Q

Contralateral impaired sensations of position and movement and tactile discrimination seen in Medial Medullary Syndrome is due to damage to what?

A

Medial lemniscus, damage DCML pathway

42
Q

Contralateral hemiparesis seen in Medial Medullary Syndrome is due to damage to what?

A

Corticospinal tract

43
Q

Damage to CN XII in Medial Medullary Syndrome causes what symptoms?

A

Ipsilateral paralysis of tongue muscles with deviation to the paralyzed side when tongue is protruded

44
Q

Degeneration of which brainstem region causes Parkinsonism?

A

Substantia nigra in Midbrain

MBBS II HNNS (57 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions