Download Lab 7 - Cranial Nerves and Pain_revised

Classification of Nerves
 Sensory and motor divisions
 Sensory (afferent) – carry impulse to the CNS
 Motor (efferent) – carry impulses from CNS
 Mixed – sensory and motor fibers carry impulses to
and from CNS; most common type of nerve
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Cranial Nerves
 Twelve pairs of cranial nerves arise from the brain
 They have sensory, motor, or both sensory and
motor functions
 Each nerve is identified by a number (I through XII)
and a name
 Four cranial nerves carry parasympathetic fibers that
serve muscles and glands
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Cranial Nerves
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Figure 13.5a
Cranial Nerves
I
Olfactory
Sensory from nose for sense of smell
II
Optic
Sensory from eye for vision
III
Oculomotor Motor to eye muscles for movements of
the eyes
IV
Trochlear
V
Trigeminal
VI
Abducens
VII
Facial
Motor to eye muscles for movements of
the eyes
Sensory info from face, scalp, and teeth
Motor impulses to chewing muscles
Motor to eye muscles for abduction of the
eyes
Sensory info from some taste buds
Motor impulses to muscles controlling
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facial expressions
Cranial Nerves - 2
VIII Vestibulocochlear Sensory from ear for senses of both
sound and balance
IX
Glossopharyngeal Sensory from throat and some taste buds
Motor to muscles of throat for
swallowing and to salivary glands
X
Vagus
Sensory from throat, larynx, thoracic and
abdominal organs
Motor impulses to stimulate digestive
organs, to slow heart rate, and to
swallow
XI
Accessory
Motor impulses to muscles of the neck
and upper shoulder for shoulder
movements and movements of the head
Motor impulses to muscles of the tongue
XII Hypoglossal
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How to learn the Cranial Nerves
 Pneumonic for Name of Cranial Nerves
 Oh, Oh, Oh, To Touch And Feel Very Good Velvet,
AH
 On occasion our trusty truck acts funny, very good
vehicle any how.
 Pneumonic for Classifications of Cranial Nerves
 Some say Marilyn Monroe, but my brother says
Bridget Bardot, my, my.
 Some say marry money but my brother says big
business makes money.
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Figure UN 13.1
Perceptual level (processing in
cortical sensory centers)
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Motor
cortex
Somatosensory
cortex
Thalamus
Reticular
formation
Pons
2 Circuit level
(processing in
Spinal
ascending pathways) cord
Cerebellum
Medulla
Free nerve
endings (pain,
cold, warmth)
Muscle
spindle
Receptor level
(sensory reception Joint
and transmission
kinesthetic
to CNS)
receptor
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Figure 13.2
Perception of Pain
 Warns of actual or impending tissue damage
 Stimuli include extreme pressure and temperature,
histamine, K+, ATP, acids, and bradykinin
 Impulses travel on fibers that release
neurotransmitters glutamate and substance P
 Some pain impulses are blocked by inhibitory
endogenous opioids