L-14 Brainstem And Cranial Nerves

Front 1

Major subdivisions of brainstem

Back 1

Mesencephalon

Pons

Medulla

Front 2

Mesencephalon structures

Back 2

Cerebral aqueduct - connects third and fourth ventricle.

Tectum - Ceiling of cerebral aqueduct, composed of superior and inferior colliculi

Tegmentum - Floor of cerebral aqueduct

Front 3

Medulla

Back 3

Open portion which borders fourth ventricle

Closed portion unconnected to ventricles

Front 4

Cerebellum

Back 4

Connected to mesencephalon by superior cerebellar peduncle

Connected to pons by middle and inferior cerebellar peduncles

Front 5

Structures of brainstem

Back 5

Midline groove

On either side is sulcus limitans

Rhomboid shaped fourth ventricle, bottom is called obex.

Middle cerebellar peduncle connecting cerebellum to pons

Front 6

Sulcus limitans importance

Back 6

Sulcus limitans separates motor nuclei from autonomic and sensory nuclei.

Front 7

Back 7

Pyramids

Base of pons with basilar artery

Pyramidal decussation

Abducens nerve

Front 8

Cranial nerves on medial and lateral side of olive

Back 8

Medial side of olive (medial periolivary groove) - XII

Lateral side of olive (lateral periolivary groove) - IX, X, XI

Front 9

Back 9

Inferior olive

Front 10

Difference between organization of brain stem and spinal cord

Back 10

Dorsal horn (somatic and visceral sensory) of spinal cord moves to be lateral

Ventral horn (somatic and visceral motor) of spinal cord moves to be medial

Front 11

Precursor of sensory and motor nuclei

Back 11

Alar plate gives rise to sensory nuclei

Basal plate gives rise to motor nuclei

Alar and motor plate are separated by sulcus limitans

Front 12

Order of brainstem nuclei

Back 12

Medial (purely motor) - III, IV, VI, XII

Lateral but medial to sulcus limitans - V, VII, nucleus ambiguus (IX, X, XI)

Lateral - autonomic centers i.e.salivatory nuclei

Lateral-most - sensory nuclei - mesencephalic nucleus of trigeminal, principal nucleus of trigeminal, spinal trigeminal nucleus (sensory nerves for V, VII, IX, X, XI)

Front 13

Sensory information in cranial nerves

Back 13

General sensory: touch, temperature, pain, spindles

Visceral sensory: stretch, visceral pain

Special sensory: vision, hearing, smell, taste

Front 14

Motor information in cranial nerves

Back 14

Somatic motor from somite or branchial arches derived muscles

Visceral motor - parasympathetic (craniosacral)

Front 15

First order sensory neurons

Back 15

Pseudounipolar cells

Ganglion is outside brain typically.

Except mesencephalic sensory neurons, where ganglion is in brainstem

Front 16

Sensory nuclei

Back 16

Dorsal and ventral cochlear nuclei (VIII) - hearing

Medial, lateral, superior,inferior vestibular nuclei (IX) - balance

Mesencephalic nucleus of trigeminal nerve (V) - proprioceptive reflex

Principal sensory nucleus of trigeminal nerve (V) - somatosensory

Spinal nucleus of trigeminal nerve (V, VII, IX, X) - somatosensory

Nucleus of solitary tract - (IX, X) - special sensory

Front 17

Spinal trigeminal nucleus

Back 17

Sensory nerves for V, VII, IX, X, XI

Continuation of dorsal horn's substantia gelatinosa

Front 18

Motor nuclei

Back 18

Oculomotor (III)

Trochlea (IV)

Trigeminal (V)

Abducens (VI)

Facial (VII)

Nucleus ambiguus (IX, X, XI)

Accessory nucleus (XI)

Hypoglossal nucles (XII)

Front 19

Edinger-Westphal nucleus

Back 19

Autonomic but located medial to motor nucleus of oculomotor

Joins oculomotor nerve, Innervates ciliary ganglion which sends fibers to muscle of eye to regulate pupil size.

Front 20

Parasympathetic functions

Back 20

Pseudomotor - regulate secretion

Vasomotor - regulate smooth muscle

Front 21

Parasympathetic motor nuclei

Back 21

Edinger-Westphal nucleus (leave through III)

Superior salivatory nucleus (leave through VII) - to pterygopalatine, submandibular, and sublingual

Inferior salivatory nucleus (leave through IX) - to otic ganglion, innervate parotid

Dorsal motor nucleus of vagus

Front 22

Trigeminal autonomics

Back 22

Trigeminal system has no autonomics but other cranial nerves travel along trigeminal to reach target

e.g. auriculotemporal n. to parotid

Front 23

Colliculus facialis

Back 23

Protrusion on floor of fourth ventricle

Formed by fibers leaving facial nucleus looping around abducens nuclei.

Medial protrusions are motor, lateral are sensory, and in between but lateral to sulcus limitans is autonomic.

Front 24

Oculomotor nerve

Back 24

Motor nucleus just below Edinger-Westphal

Front 25

Back 25

Mesencephalic spinal trigeminal nucleus

Front 26

Trochlear nucleus

Back 26

Supplies superior oblique

Front 27

Trigeminal nerve system

Back 27

Has somatosensory and somatomotor nucleus in pons

Tract comes up from spinal cord as substantia gelatinosum and continues up to mesencephalon at level of oculomotor nerve.

Front 28

Back 28

In pons, motor nucleus of trigeminal nerve is medial to principal nucleus of trigeminal nerve

Front 29

Back 29

Tract of spinal trigeminal nucleus is lateral to nucleus

Front 30

Back 30

Abducens n.

Front 31

Back 31

Front 32

Facial nerve

Back 32

Motor

Autonomic efferent - superior salivatory

Visceral sensory - nucleus of solitary tract

General sensory - spinal trigeminal nucleus

Front 33

Back 33

Front 34

Vestibulocochlear nerve

Back 34

Cochlear nuclei and vestibular nucleus

Front 35

Glossopharyngeal nerve

Back 35

General sensory from tongue, ear - Spinal trigeminal

Autonomic - inferior salivatory (otic)

Special sensory from carotid body, tastef - solitary tract

Motor to stylopharyngeus - nucleus ambiguus

Front 36

Vagus nerve

Back 36

Nucleus ambiguus - striated to pharynx, tongue, larynx

Dorsal nucleus of vagus - parasympathetic

Solitary tract - special sensory i.e. taste from epiglottis

Spinal trigeminal - general sensory

Front 37

Back 37

Front 38

Back 38

Front 39

Structures around middle cerebellar peduncle

Back 39

Connects cerebellum to pons

In front - trigeminal

Behind - facial and vestibulocochlear

Front 40

Find abducens

Back 40

Between pons and medulla close to midline

Front 41

Identifying oculomotor nerve

Back 41

In front of pons behind medullary body between posterior cerebellar and posterior cerebral artery.