Transcript ch 5 slideshow

Chapter 5
Lower motor neurons:
Flaccid Paralysis
pyramidal system
(Alpha)
In the spinal
cord
and
brainstem
Fig. 5-1
Cranial Nerve Pairs
CN I
CN II
CN III
CN IV
CN V
CN VI
CN VII
CN VIII
Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Abducens
Facial
Vestibulocochlear
CN IX
CN X
CN XI
Glossopharyngeal
Vagus
Spinal Accessory
All CN’s (except
I, II, and VIII)
contain the
axons of lower
motor neurons
VI
Class
Structure Innervated
Somatic motor (GSE)
Striated muscle derived from somites
Visceral motor (GVE)
Smooth muscle of blood vessels, glands, and organs
Branchial motor (SVE)
Striated muscle derived from branchial arches
General sensory (GSA)
Mechanical, pain/temperature, proprioception of skin, mucous membranes, and skeletal muscle of
head and neck
Visceral sensory (GVA)
Mechanical, pain/temperature, proprioception of oral cavity, pharynx and larynx
Special somatic sensory (SSA)
Vision, audition and balance
Special visceral sensory (SVA)
Olfaction, taste
Nerve
Somatic motor
Branchial motor
Visceral motor
Visceral
sensory
General sensory
Special sensory
I. Olfactory
olfaction
II. Optic
vision
III. Oculomotor
extraocular
muscles, except
superior oblique
and lateral
rectus
IV. Trochlear
superior oblique
muscle
V. Trigeminal
VI. Abducens
pupillary
constrictor and
ciliary muscles
muscles of mastication,
tensor tympani, tensor
veli palati, anterior belly
of digastric, mylohyoid
lateral rectus
muscle
face, anterior scalp,
eyes, nasal and oral
cavities, anterior 2/3 of
tongue, external
tympanic membrane,
meninges of anterior
and middle cranial
fossae
Nerve
Somatic motor
VII. Facial
Branchial motor
muscles of facial
expression, stapedius,
stylohyoid and
posterior belly of
digastric
Visceral motor
Visceral
sensory
lacrimal, oral,
nasal,
submandibular, and
sublingual glands
General
sensory
ear, external
auditory
meatus,
tympanic
membrane
VIII.
Vestibulocochlear
Special sensory
taste for anterior
2/3 of tongue
audition and
balance
IX.
Glossopharyngeal
Stylopharyngeus m.
parotid gland
carotid body
and carotid
sinus
posterior 1/3
tongue, ear,
typanic
membrane,
Pharynx
taste for posterior
1/3 of tongue
X. Vagus
pharynx and larynx
muscles, including
palatoglossus
pharynx, larynx,
thoracic and
abdominal viscera
visceral
sensation,
larynx and
pharynx,
aortic body
external
tympanic
membrane,
posterior
meninges,
larynx
taste for the
epiglottis (minor)
XI. Accessory
Sternocleidomastoid
and trapezius muscles
XII. Hypoglossal
Intrinsic and
extrinsic
muscles of the
tongue
olfactory
bulb
olfactory tract
II
III
VI
IV
V
VII, VIII
I
II
(midbrain)
VIII
Lesions
lead to:
VIII
Fig. 21-2
Distribution and relationships of brainstem motor nuclei:
rostral
caudal
Fig. 5-3
III, IV, VI – for eye movements
(lateral view of left orbit)
II
VI
V1
III
IV
Fig. 5-4
Right eye movements:
inferior oblique
lateral rectus
superior oblique
superior rectus
medial rectus
inferior rectus
CN III
Fig. 5-4
lesion of the nucleus or nerve  ipsilateral signs
CN III – 1 of 4 Parasympathetic cranial nerves
Ophthalmoplegia:
Fig. 5-4
Oculomotor Nerve Palsy (right)
Oculomotor Nerve Palsy (left)
CN IV
Fig. 5-5
lesion of the nucleus  contralateral signs
lesion of the nerve  ipsilateral signs
diplopia is especially noticeable
walking down stairs
the inferior rectus and inferior oblique mm. extort the eye
the superior rectus and superior oblique mm. intort the eye
extorsion
intorsion
intorsion
(superior view of right eye)
normal extorsion of right eye and intorsion of left eye
following head tilt to the left
Fig. 5-5
Trochlear Nerve Palsy (right)
extorsion – left eye
(lesion of left trochlear nerve)
compensatory head tilt to right
compensatory intorsion of the unaffected
eye permits binocular alignment
Right eye movements:
inferior oblique
lateral rectus
superior oblique
superior rectus
medial rectus
inferior rectus
CN IV lesion  impaired depression after adduction
CN VI
Fig. 5-7
lesion of the nucleus or nerve  ipsilateral signs
Fig. 5-7
Abducens nerve lesion (left)
V
(V1)
(V2)
(V3)
CN V
Fig. 5-6
lesion of the nucleus, motor root or mandibular
branch  ipsilateral signs
(branches of V3)
Fig. 5-6
deviation of jaw
Fig. 21-4
Trigeminal Nerve Paralysis (right)
Trigeminal Neuralgia
(tic douloureux)
VII, VIII
IX
X
XI
VII
CN VII
facial colliculus
Fig. 5-8
lesion of the nucleus or nerve  ipsilateral signs
(2 parts)
CN VII – one of four Parasympathetic cranial nerves
dry mouth
no closure of eye
no mouth of retraction
Fig. 21-5
Facial Nerve Palsy (right)
(Bell’s Palsy)
Corneal Reflex
Afferent Limb – CN V
Efferent Limb – CN VII
LMN vs. UMN
facial weakness
CN IX, X, XI
IX
X
XI
Fig. 5-9
lesion of the nuclei or nerves  ipsilateral signs
CN IX – one of four Parasympathetic cranial nerves
loss of
gag reflex
(slight)
loss of carotid
body reflex
Fig. 21-6
X
CN X – one of four Parasympathetic cranial nerves
Dysphagia
weakness
of voice
Fig. 21-7
sternocleidomastoid
trapezius
nucleus ambiguus
in medulla
accessory nucleus
in ventral horn of
spinal cord segments
C1-C5
(right)
Spinal Accessory Nerve Palsy (left)
Due to lesion of
spinal accessory
nucleus in cervical
spinal cord or spinal
root of CN XI
(not due to lesion of
nucleus ambiguus)
CN XII
lesion of the nucleus or nerve  ipsilateral signs
supplies the intrinsic and
extrinsic tongue muscles
Hypoglossal Nerve Palsy (right)
dorsal view
Chapter 5 (pgs. 48-55) and Chapter 21
know the points of attachment or emergence of the cranial nerves III-XII
know the levels of the brainstem where the nuclei of the motor cranial nerves are found
know the components of the cranial nerves
know the functions of the cranial nerves
know the signs/symptoms associated with lesions of the cranial nerves