ANA300 - Brainstem and cranial nerves

In both the brainstem and spinal cord, grey matter is ___ and white matter is ___

deep, superficial

In both the brainstem and spinal cord, white matter consists of axons carrying sensory information _____, and motor information ________

rostrally, caudally

While grey matter in the spinal cord is a ________, grey matter in the brainstem is ______

continuous column, broken up into a discontinuous series of functionally specialized nuclei

Both brainstem and spinal cord subserve ___ and ___ functions

somatic, autonomic

Unlike the spinal cord, the brain stem subserves ____ and contains a ______ responsible for the maintenance of ____ and ____

special senses, reticular formation, vital functions, arousal

Descending fibre tracts in the brainstem carry _____ from the cerebral cortex to the spinal cord controlling ______: _______

voluntary output, contralateral body, corticospinal tract

Descending fibre tracts carry voluntary output from _____ to _____ controlling (contralateral, ipsilateral, bilateral) ____: _______

cerebral cortex, brainstem, face, corticobulbar tract

Descending fibre tracts also made of involuntary tracts that modulate

• Posture, muscle tone, balance (vestibulospinal tract)

• Autonomic functions (hypothalamus)

Ascending fibre tracts from the spinal cord to the ____ transmit somatosensory info destined for ______

thalamus, conscious appreciation in the cerebral cortex

Ascending fibre tracts from the spinal cord to the _____ transmit _______ input from muscles and joints

cerebellum, subconscious proprioceptive input

Peduncles: 

white matter bundles

Paired superior cerebral peduncles join the ____ and _____

midbrain, cerebral hemispheres

3 paired cerebellar peduncles join the ____ and _____

brainstem, cerebellar hemispheres

A & B

A: Diencephalon

B: Optic nerve

C-F

C: Midbrain

D: Cerebral peduncles

E: Occulomotor nerves

F: Trochlear nerves

G-K

G: Pons

H: Trigeminal nerves

I: Abducens nerves

J: Facial nerves

K: Vestibulocochlear nerves

L-R

L: Medulla

M: Glossopharyngeal nerves

N: Vagus nerves

O: Accessory nerves

P: Pyramids

Q: Hypoglossal nerves

R: Olives

Cerebral peduncles are mostly _______-

axons of the corticospinal tract

Trochlear nerves are the only CNs arising from the ______

dorsal aspect

Trigeminal nerves mostly carry 

sensory information from the face

Facial nerves

Motor neurons

Vestibulocochlear neres

Special senses

Vagus nerves

PNS outflow to thorax and abdominal viscera

Accessory nerves arise from the _______, enters the cranium through the _______, exits through the _______-

upper cervical segment, foramen magnum, jugular foramen

The superior cerebellar peduncles connect the ______ and _________

midbrain, cerebellum

The middle cerebellar peduncles connect the ____ and _____

pons, cerebellum

Inferior cerebellar peduncles connect the ____ and ____

medulla, cerebellum

The cerebellum overlies the ______

fourth ventricle

A-B

A: Thalami

B: Pineal gland

C-G

C: Midbrain

D: Superior colliculus (vision)

E: Inferior colliculus (hearing)

F: Trochlear nerve

G: Superior cerebellar peduncle

H-J

H: Pons

I: Middle of cerebellar peduncle

J: Floor of 4th ventricle

K-O

K: Medulla

L: Inferior cerebellar peduncles

M: Posterior median sulcus

N: Gracile tubercle

O: Cuneate tubercle

A-F

A-C: Superior, middle, inferior cerebellar peduncles

D: Cortical grey matter

E: Subcortical white matter

F: Cerebellar nuclei

Cerebellum made of two _____

bilaterally paired hemispheres

Cerebellum controls ___, ____ and coordination of _______

posture, balance, motor function

Spinocerebellar proprioceptive info into cerebellum reports ___________ and _____

ipsilateral body position, muscle tone

Vestibulo-cerebellar input into cerebellum reports _____ and ______-

position, acceleration of the head in space

Contralateral corticopontocerebellar afferents into the cerebellum report

movement planning

Motor and premotor cortex output from the cerebellum via _____

thalamus

Motor cortex controls movement of ______

contralateral body

Like the body, the head has both

sensory and motor components, voluntary and involuntary components

Unlike the spinal cord, functional columns disperse into a series of ______

longitudinally arranged, distinct nuclei 

Unlike spinal nerves, CNs may carry a _________

single modality

Unlike the spinal cord, the brainstem and cranial nerves subserve ______

“special” visceral sensation, taste and the “special senses” of hearing balance

Somatic components of spinal cord and cranial nerve

• Somatic voluntary motor

• Somatic sensory

Autonomic components of spinal cord and cranial nerves

• Visceral motor

• Visceral sensory

• Visceral sensory including taste

• Hearing and balance

Cranial nerves that convey special senses

• I (Olfactory N)

• II (Optic N)

• VIII (vestibulocochlear N)

Cranial nerves that control skeletal muscle

• III (Oculomotor N)

• IV (trochlear N)

• VI (abducens N)

• XI (accessory N)

• XII (hypoglossal N)

Mixed cranial nerves

• V (trigeminal N)

• VII (facial N)

• IX (glossopharyngeal N)

• X (vagus N)

Olfactory nerve conveys _____ from the ______ in the roof of the nasal cavity

smell, olfactory epithelium

Olfactory nerves enter cranium by passing through the _________-

Cribiform plate of the ethmoid

Optic nerve conveys ______ from the ______

visual input, retina

Optic nerve enters the cranium through the _______

Optic foramen

Vestibulocochlear nerve conveys _______ from the ____ via the cochlear division and ______ from the _______ via the vestibular division

auditory sensations, cochlea, balance info, vestibular apparatus

Vestibulocochlear nerve enters cranium through the __________

internal auditory (acoustic) foramen

Cranial nerves III, IV, VI exit the cranium through the _______ to enter ___

superior orbital fissure, orbit

Cranial nerves III, IV, and VI control _______ that position the eye in orbit

extraocular eye muscles

Nerve damage to cranial nerves III, IV, and VI can cause ____ () and _____ ()

strabismus (misaligned eye), diplopia (double vision)

Cranial nerves III, IV, and VI also control the _______ (paralysis causes _____) and _______ (nerve damage causes ______)

levator palpebrae superioris, ptosis (droopy eyelid), parasympathetic preganglionic fibres, mydriasis (enlarged pupil)

The accessory nerve (__) emerges as a series of rootlets from the _________

XI, lateral aspect of upper cervical cord

The accessory nerve enters cranium through ______ and exits via _____ with CN and_

foramen magnum, jugular foramen, IX, X

The accessory nerve controls the ______ and _____

sternocleidomastoid, trapezius muscles

SCM ___________ and the trapezius _____

opposite side, elevates the shoulder

The hypoglossal nerve (__) exits the cranium via _____ and controls the shape and position of tongue via _____

XII, hypoglossal canal, intrinsic, extrinsic muscles

The trigeminal nerve is a ___ cranial nerves, conveying _______ from the face

mixed, somatic sensation

3 divisions of the trigeminal nerve

• Opthalmic division

• Maxillary division

• Mandibular division

Opthalmic division exits the cranium via the _____

superior orbital fissure

Maxillary division exits via the ______

foramen rotundumM

Mandibular division exits via the ______

foramen ovale

Trigeminal ganglion contains the cell bodies of _______

pseudounipolar somatic sensory neurons

Mandibular division also ______ to the ________

voluntary motor, 4 muscles of mastication

Facial nerve (__) exits the cranium via the _______

CN VII internal auditory (acoustic) foramen

Voluntary motor fibres of facial nerve exit skull via ________ to innervate ______

stylomastoid foramen, muscles of facial expression

Facial nerve senses __________ from the _____ of the tongue through axons in ____ and cell bodies in _____

Special visceral sensory taste, anterior 2/3, chorda tympani, geniculate ganglion

Facial nerve is parasympathetic preganglionic via ______ to ______: postganglionic fibres distributed to the ______, ____, and ____, ___ the oral fissure

chorda tympani, submandibular ganglion; submandibular, sublingual glands, oral mucosa, below

Facial nerve is parasympathetic preganglionic via the _______ to the __________: postganglionic fibres distributed to the ____, _____ and ______, _____ the oral fissure

greater petrosal nerve, pterygopalatine ganglion, lacrimal gland, nasal mucosa, oral mucosa

Facial nerve damage causes ____

Bell Palsy

The glossopharyngeal nerve () exits the cranium via the ______

CN IX, jugular foramen

The glossopharyngeal nerve is responsible for ______  and from the  _____ of the tongue, and ______

somatic sensory, special visceral, 

The vagus nerve () exits the cranium via the _____

X, jugular foramen

The vagus nerve has ______ control to the pharynx and larynx, and ______from the _____ and ______

voluntary motor, general sensory. laryngopharynx, larynx

The vagus nerve has ______ nerves from _____ in the aortic body and ______ in the aortic arch, ____ and most _____-

chemoreceptors, baroreceptors. thoracic, abdominal viscera

The vagus nerve has _________ to the intramural ganglia of _____

parasympathetic preganglionic fibres, thoracic and abdominal viscera