Transcript 26. Mixed cranial nervest

Mixed
cranial
nerves
• 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 and VIII are purely
sensory.
• Cranial nerves III, IV, VI, XI and XII are
motor (although also function balance).
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
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)
Nervous System II: Cranial Nerves
Cranial nerves
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)
Cranial Nerve V Trigeminal
• Sensory from face, cornea, mouth, nose,
temporomandibular joint
• Motor to muscles of mastication
V Trigeminal Nerve
• Sensory information
from the face and
body is processed by
parallel pathways in
the central nervous
system.
Cranial nerves
V: Trigeminal (3 nerves in 1!)
• V1. Ophthalmic
– Exits with eye muscle group (superior orbital fissure, through orbit to
superior orbital notch/foramina)
– Sensory to forehead, nasal cavity
• V2. Maxillary
– Exits foramen rotundum through wall of maxillary sinus to inferior
orbital foramina)
– Sensory to cheek, upper lip, teeth, nasal cavity
• V3. Mandibular
–
–
–
–
Exits foramen ovale to mandibular foramen to mental foramen
Motor to jaw muscles--Masseter, temporalis, pterygoids, digastric
Sensory to chin
Sensory to tongue
Human Anatomy, Frolich, Head/Neck IV: Cranial Nerves
Human Anatomy, Frolich, Head/Neck IV: Cranial Nerves
CN VI: ABDUCENS AND CN
VII: FACIAL
• Cranial Nerve VI
• Function: Eye
movements
• Clinical test: lateral eye
movement
• Effects of damage:
inability to rotate eye
laterally; at rest – eye
rotates medially
because of action of
antagonistic muscles
• Cranial Nerve VII
• Function: facial
expression; sense of
taste
• Clinical test: motor
functions – close eyes,
smile, whistle, frown,
raise eyebrows; taste
• Effects of damage:
inability to control facial
muscles; distorted
sense of taste
• 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)
Cranial Nerve VII Facial
• Sensory from anterior 2/3 of tongue
• Motor to muscles of facial expression
• Parasympathetic to salivary and lacrimal
glands
• Injury causes facial droop, dry eyes, dry
mouth
VII Facial Nerve
• Supplies the
muscles of facial
expression
VII: Facial Nerve
(exits cranial cavity with VIII--internal auditory meatus)
• Facial muscles (five branches fan out over face from
stylomastoid foramen)
–
–
–
–
–
Temporal
Zygomatic
Buccal
Mandibular
Cervical
• “chorda tympani” (crosses interior ear drum to join V3 )
– Taste to anterior 2/3 of tongue
– Submandibular, sublingual salivary glands
• Lacrimal glands
Human Anatomy, Frolich, Head/Neck IV: Cranial Nerves
Human Anatomy, Frolich, Head/Neck IV: Cranial Nerves
Cranial Nerve IX Glossopharyngeal
• Sensory posterior 1/3 of tongue, auditory
tube, pharynx
• Parasympathetic to parotid gland
Human Anatomy, Frolich, Head/Neck IV: Cranial Nerves
IX Glossopharyngeal
• Innervates the muscle
that allows you to
swallow
CN IX: GLOSSOPHARANGEAL
AND CN X: VAGUS
• Cranial Nerve IX
• Function: swallowing,
salivation, gagging; touch,
pressure, taste, and pain
sensations from tongue,
pharynx, and outer ear
• Clinical tests: gag reflex,
swallowing, and coughing
• Effects of damage: difficulty
swallowing
• Cranial Nerve X
• Function: swallowing; taste;
speech; respiratory, CV, and
GI regulation; sensations of
hunger, fullness, and
intestinal discomfort
• Clinical tests: test with
cranial nerve IX
• Effects of damage:
hoarseness or loss of voice;
impaired swallowing and GI
motility
Cranial Nerve X Vagus
• Sensory larynx and pharynx
• Motor to larynx and pharynx
• Parasympathetic to chest and abdomen
• 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)
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
Human Anatomy, Frolich, Head/Neck IV: Cranial Nerves