Block II: intro cranial nerves & autonomics of head

Question 1

mention the cranial nerves

Answer 1

I Olfactory
II optic
III Oculomotor
IV Trochlear
V Trigeminall
VI Abducens
VII Favial
VIII Vestibulocochlear
IX Glossopharyngeal
X Vagus
XI Accessory
XII hypoglossal

Question 2

Which cranial nerves are motor?

Answer 2

III Oculomotor
IV Trochlear
VI Abducens
XI Accesssory
XII Hypoglossal

Question 3

Whcih cranial nerves are sensory?

Answer 3

I olfactory
II Optic
VIII Vestibulocochlear

Question 4

Which cranial nerves are mixed sensory and motor?

Answer 4

V Trigeminal
VII Facial
IX Glossopharyngeal
X Vagus

Question 5

which are the 3 sensory afferent modalities?

Answer 5

General Somatic Afferent (GSA or general sensory):
touch, pain, temperature, pressure, vibration, proprioception

General Visceral Afferent (GVA or visceral sensory):
sensory input from viscera (except visceral pain in the majority of cases, which travels through sympathetic nerves)

Special Visceral Afferent (SVA or special sensory):
smell, vision, taste, hearing, balance

Question 6

which are the 3 motor efferent modalities?

Answer 6

General Somatic Efferent (GSE or somatic motor):
muscles that develop from somites (skeletal muscle)

Special Visceral Efferent (SVE or branchial motor):
muscles that develop from branchial or pharyngeal arches
(skeletal muscle)

General Visceral Efferent (GVE or visceral motor):
viscera, including glands and smooth muscle

Question 7

Which cranial nerves have general sensory (GSA?

Answer 7

V Trigeminal
VII Facial
IX Glossopharyngeal
X Vagus

Question 8

Which cranial nerves have visceral sensory (GVA?

Answer 8

IX Glossopharyngeal
X Vagus

Question 9

Which cranial nerves have special sensory (SVA?

Answer 9

I Olfactory
II Optic
VII Facial
VIII Vestibulocochlear
IX Glossopharyngeal
X Vagus

Question 10

Which cranial nerves have somatic motor (GSE?

Answer 10

III Oculomotor
IV Trochlear
VI Abducens
XII Hypoglossal
XI accessory (aveces))

Question 11

Which cranial nerves have branchial motor (SVE?

Answer 11

V Trigeminal
VII Facial
IX Glossopharyngeal
X Vagus
XI Accessory

Question 12

Which cranial nerves have visceral motor (GVE?

Answer 12

III Oculomotor
VII Fcaial
IX glossopharyngeal
X Vagus

Question 13

which are the sensory gnaglions associated to cranial nerves?

Answer 13

*Semilunar g. (CN V)
*Geniculate g. (CN VII
*Spiral g. (CN VIII)
*Sup & Inf Glossopharyn . g. (CN
*Sup & Inf Vagus g. (CN X)

Question 14

where is th eorimary sensory neuron located

Answer 14

cell body outside CNS in a
sensory ganglion

Question 15

where is the secondary sensory neuron located?

Answer 15

cell body in nuclei of brainstem dorsal
gray matter; Axons usually cross the midline
to project to thalamus on
opposite (contralateral) side

Question 16

which are the sensory nucleus in the brianstem?

Answer 16

*Nucleus of Spinal Tract
*Pontine Sensory Nucleus
*Mesencephalic Nucleus of CN V
*Vestibular Nucleus
*Cochlear Nucleus
*Nucleus Solitarius

Question 17

where are soma of tertiary sensory neuron located?

Answer 17

thalamic nuclei

Question 18

whch lesions can happen with afferent neurons?

Answer 18

Total loss of sensation- anesthesia
Partial loss of sensation-hemianesthesia
Total loss of pain-analgesia
Partial loss of pain-hemianalgesia

Question 19

damage in primary neuron (peropheral nerve) causes:

Answer 19

loss of sensation from same side
(ipsilateral)

Question 20

damage in soma of nuclei in breainstem neuron causes:

Answer 20

loss of sensation from same side
(ipsilateral)

Question 21

damage in soma in thalamic nuclei after it crosses causes:

Answer 21

loss of sensation from opposite side
(contralateral)

Question 22

damage in sensory cortex or tertiary neuron causes:

Answer 22

loss of sensation from opposite side
(contralateral)

Question 23

where is th eupper motor neuron located?

Answer 23

soma in cortex

Question 24

where does the axon of upper motor neuron project to?

Answer 24

its axon projects to neurons in
brainstem nuclei, usually (but not
always) on both sides of the
midline (bilaterally)

All head & neck muscles are
represented bilaterally, except the
sternocleidomastoid, trapezius,
muscles of the tongue and the
lower half of the face

Question 25

where is lower motor neuron located and where does it project to?

Answer 25

*cell body located in brainstem or upper cervical spinal cord *its axon projects to skeletal muscle of somatic or branchial origin through branches of cranial nerves

Question 26

which nerves has motor nuclei in brainstem?

Answer 26

*Oculomotor Nucleus (CN III) *Trochlear Nucleus (CN IV) *Masticator Nucleus (CN V) *Abducens Nucleus (CN VI) *Facial Nucleus (CN VII) *Nucleus Ambiguus (CN IX, X) *Accessory Nucleus (CN XI) *Hypoglossal Nucleus (CN XII)

Question 27

which are the lesions of the motor efferent neurons?

Answer 27

Total loss of movement - paralysis Partial loss of movement - paresis Increased muscle tone - spasticity Loss of muscle tone - flaccidity Exagerated reflexes - hyperreflexia Muscle wasting - atrophy Loss of coordination - ataxia Fasciculations- random twitching of small muscle groups

Question 28

what happens in upper motor neuron lesion (UMNL)

Answer 28

*paresis or paralysis when voluntary movement is attempted *spasticity *hyperreflexia *symptoms not usually observable in parts of the body that are supplied by bilateral UMN projections

Question 29

what happens in lower motor neuron lesion (LMNL)

Answer 29

*paresis or paralysis *flaccidity *hyporeflexia or areflexia *atrophy *Fasciculation

Question 30

first order neurons of visceral motor efferent pathways (autonomic) are?

Answer 30

cell body within CNS diencephalon and brainstem *Hypothalamus *Olfactory system *Autonomic centers in the brainstem reticular formation

Question 31

presynaptic neurons (parasympathetic) secondary neurons of the automic are where?

Answer 31

cell body within brainstem nuclei (4 parasympathetic nuclei) *Edinger Westphal Nucleus - oculomotor *Superior Salivatory Nucleus - facial *Inferior Salivatory Nucleus - glossopharung *Dorsal Vagal Nucleus - vagus

Question 32

postsynaptic neurons (postganglionic) efefrent autonomic are where?

Answer 32

cell body within ganglia of the head, and distributed throughout autonomic plexuses of the thorax or abdomen (4 ganglion parasympathetic) *Ciliary ganglion *Pterygopalatine ganglion *Otic ganglion *Submandibular ganglion

Question 33

Presynaptic parasympathetic fibers in the head are found in the following cranial nerves:

Answer 33

CN III (Oculomotor) CN VII (Facial) CN IX (Glossopharyngeal) CN X (Vagus) Part of the parasympathetic fibers of the facial andglossopharyngeal nerves travel through short stretches ofbranches of the trigeminal nerve (CN V), such as the lingual, lacrimal and auriculotemporal nerves.

Question 34

The targets of the postsynaptic parasympathetic fibers in the head include:

Answer 34

* Sphincter muscle of the pupil * Ciliary muscle (involved in accommodation of the lens) * Lacrimal gland (stimulate secretion) * Salivary glands ( parotid, sublingual and submandibular; stimulate secretion)

Question 35

ALL sympathetic fibers to the head are:

Answer 35

postsynaptic

Question 36

soma of postsynaptic sympathetic fibers are in?

Answer 36

Superior Cervical Ganglion (SCG)

Question 37

where do presynaptic sympathetic fibers com from?

Answer 37

The presynaptic fibers that drive the neurons in the SCG have their cell bodies in the lateral horn of the gray matter of the superior thoracic spinal cord. The presynaptic axons travel in the ventral roots, incorporate in spinal nerve, salen del spinal nerve por el white rami communicantes and enter the interganglionic connectives to reach the SCG.

Question 38

how do axons from postsynaptic sympathetic neurons distribute? and

Answer 38

Axons of the postsynaptic sympathetic neurons travel along the internal carotid nerve and plexi that form around the external and internal carotid arteries and its ramifications

Question 39

From these plexi, the postsnaptic sympathetic neurons the fibers use three routes to reach their targets:

Answer 39

(1) plexi along branches of the external and internal carotid arteries (2) branches of cranial nerves (3) sympathetic nerves (deep petrosal nerve and sympathetic root of ciliary ganglion)

Question 40

The targets of the postsynaptic sympathetic fibers of the head are the:

Answer 40

* sweat glands * arrector pili muscles of the skin * walls of blood vessels (including those of the lacrimal and salivary glands and nasal and oral mucosa) * tarsal part (smooth muscle) of levator palpebrae * dilator pupillae muscle

Question 41

what happens if there is damage of postsynaptic fibers of sympathetic?

Answer 41

Horner’s Syndrome: * Anhydrosis (lack of sweating) * Redness and warm skin (due to reduced * Ptosis (droopy eyelid) [only smooth muscle] * Constricted pupil