Download Brain and Cranial Nerves - PA

13-1
13-2
Nervous System II: Cranial Nerves
13-3
• Cranial nerves are part of the peripheral nervous
system.
• Carry sensory or motor information or a
combination and function in parasympathetic
nervous system.
• Cranial nerves I, II, VIII are purely sensory.
• Cranial nerves III, IV, VI, XI and XII are motor
(although also function balance).
13-4
Cranial Nerves
• Indicated by Roman
numerals I-XII from
anterior to posterior
• May have one or more of
3 functions
– Sensory (special or
general)
– Motor (skeletal muscles)
– Parasympathetic
(regulation of glands,
smooth muscles, cardiac
muscle)
• Balance
– Positional information of
body parts
13-5
Cranial Nerves
•
•
•
•
•
•
•
Olfactory (I)
Optic (II)
Oculomotor (III)
Trochlear (IV)
Trigeminal (V)
Abducens (VI)
Facial (VII)
• Vestibulocochlear (VIII)
– Also known as auditory
• Glossopharyngeal (IX)
• Vagus (X)
• Accessory (XI)
– Also known as spinal
accessory
• Hypoglossal (XII)
13-6
Mnemonic Aids for Cranial
Nerves
• To remember at least part of the sequence of the first set of
cranial nerves that begin with the letter O, try this –
You have I nose. You have II eyes.
I - Olfactory; II -- Optic
13-7
Mnemonic Aids for Cranial
Nerves
• On Old Olympus Towering Tops A Famous Vocal German
Viewed Some Hops
• Olfactory, Optic, Oculomotor, Trochlear, Trigeminal,
Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus,
Spinal Accessory (Accessory), Hypoglossal
• Oh. Oh. Ooh...To Touch And Feel Very Green Vegetables...A
H !!!
• Oh, once one takes the anatomy final- very good vacations
are heavenly!
13-8
Cranial Nerves
• Olfactory (I)
– Sensory (smell)
• Optic (II)
– Sensory (sight)
• Oculomotor (III)
– Motor (4 of 6 eye
muscles)
– Parasympathetic
(constriction of pupil,
movement of lens)
13-9
Cranial Nerves
• Trochlear (IV)
– Visual tracking of eye
• Trigeminal (V)
– Sensory (face, nasal
cavity, cheeks, lips, skin of
mandible)
–Motor (muscles of
mastication, anterior belly
of digastric, mylohyoid)
• Abducens (VI)
– Motor (1 eye muscle)
13-10
• Facial (VII)
Cranial Nerves
– Sensory (taste)
– Motor (facial muscles,
posterior belly of
digastric)
– Parasympathetic (salivary
glands, glands of nasal
cavity)
• Vestibulocochlear (VIII)
– Sensory (hearing and
balance)
• Glossopharyngeal (IX)
– Sensory (taste, back of mouth,
tonsils, middle ear)
– Motor (1 muscle of pharynx)
– Parasympathetic (salivary gland,
glands of tongue)
13-11
• Vagus (X)
Cranial Nerves
– Sensory (taste, back of mouth,
larynx, thoracic and abdominal
organs)
– Motor (muscles of larynx, 1
muscle of tongue)
– Parasympathetic (thoracic and
abdominal organs)
• Accessory (XI)
– Motor (sternocleidomastoid,
trapezius)
• Hypoglossal (XII)
– Motor (tongue
and throat muscles)
13-12
I Olfactory
• Functions in the special sense of smell or olfaction.
13-13
II Optic
• Visual information enters
the eye in the form of
photons of light which are
converted to electrical
signals in the retina. These
signals are carried via the
optic nerves, chiasm, and
tract to the lateral
geniculate nucleus of each
thalamus and then to the
visual centers of the brain
for interpretation.
13-14
III Occulomotor
• The somatic motor
component of CN III
plays a major role in
controlling the
muscles responsible
for the precise
movement of the eyes
for visual tracking or
fixation on an object.
13-15
IV Trochlear
• The superior oblique
muscle is one of the
six extraocular
muscles responsible
for the precise
movement of the eye
for visual tracking or
fixation on an object.
13-16
V Trigeminal Nerve
• Sensory information
from the face and
body is processed by
parallel pathways in
the central nervous
system.
13-17
VI Abducens
• The lateral rectus
muscle is one of the
six extraocular
muscles responsible
for the precise
movement of the eye
for visual tracking or
fixation on an object.
13-18
VII Facial Nerve
• Supplies the muscles
of facial expression
13-19
VIII Vestibulocochlear Nerve
• responsible for
transmitting sound and
equilibrium (balance)
• AKA Acoustic nerve
13-20
IX Glossopharyngeal
• Innervates the muscle
that allows you to
swallow
13-21
X Vagus
• The vagus nerve is the
longest of the cranial
nerve. Its name is derived
from Latin meaning
"wandering".
• The vagus nerve helps to
regulate the heart beat,
control muscle movement,
keep a person breathing,
and to transmit a variety
of chemicals through the
body
13-22
XI Accessory
• Innervates the
trapezius and
sternocleidomastoid
muscles.
• Shrug your shoulders
13-23
XII Hypoglossal
• Movement of the
tongue
13-24