peripheral nervous system classification of nerves

Peripheral Nervous SystemPeripheral Nervous System

Classification of NervesClassification of Nerves

Classification of NervesClassification of Nerves

Mixed nervesMixed nerves• Both sensory and motor fibersBoth sensory and motor fibers

Sensory nervesSensory nerves• Carry impulses toward the CNSCarry impulses toward the CNS

Motor nervesMotor nerves• Carry impulses away from the CNSCarry impulses away from the CNS

CNS = Central Nervous System (brain CNS = Central Nervous System (brain

and spinal chord)and spinal chord)

Cranial NervesCranial Nerves

12 pairs of nerves that mostly serve 12 pairs of nerves that mostly serve the head and neckthe head and neck

Only the pair of vagus nerves extend Only the pair of vagus nerves extend to thoracic and abdominal cavitiesto thoracic and abdominal cavities

Most are mixed nerves, but three are Most are mixed nerves, but three are sensory onlysensory only

PNS: Cranial NervesPNS: Cranial Nerves

II Olfactory nerve Olfactory nerve — sensory for smell — sensory for smell IIII Optic nerve Optic nerve — sensory for vision — sensory for vision IIIIII Oculomotor nerve Oculomotor nerve — motor fibers to — motor fibers to

eye muscleseye muscles IVIV Trochlear Trochlear — motor fiber to eye — motor fiber to eye

musclesmuscles

PNS: Cranial NervesPNS: Cranial Nerves VV Trigeminal nerveTrigeminal nerve — sensory for — sensory for

the face; motor fibers to chewingthe face; motor fibers to chewing

musclesmuscles VIVI Abducens nerveAbducens nerve — motor fibers to — motor fibers to

eye muscleseye muscles VIIVII Facial nerveFacial nerve — sensory for taste; — sensory for taste;

motor fibers to the facemotor fibers to the face VIIIVIII Vestibulocochlear nerveVestibulocochlear nerve — —

sensory for balance and hearingsensory for balance and hearing

PNS: Cranial NervesPNS: Cranial Nerves

IXIX Glossopharyngeal nerveGlossopharyngeal nerve — sensory for — sensory for

taste; motor fibers to the pharynxtaste; motor fibers to the pharynx XX Vagus nervesVagus nerves — sensory and motor — sensory and motor

fibers for pharynx, larynx, and viscerafibers for pharynx, larynx, and viscera XIXI Accessory nerveAccessory nerve — motor fibers to — motor fibers to

neck and upper backneck and upper back XIIXII Hypoglossal nerveHypoglossal nerve — motor fibers to — motor fibers to

tonguetongue

Table 7.1 (3 of 4)

PNS: PNS: Distribution Distribution of Cranial of Cranial

NervesNerves

Figure 7.24

PNS: Classification of NervesPNS: Classification of Nerves

Mixed nervesMixed nerves• Both sensory and motor fibersBoth sensory and motor fibers

Sensory (afferent) nervesSensory (afferent) nerves• Carry impulses toward the CNSCarry impulses toward the CNS

Motor (efferent) nervesMotor (efferent) nerves• Carry impulses away from the CNSCarry impulses away from the CNS

PNS: Cranial NervesPNS: Cranial Nerves

12 pairs of nerves that mostly serve 12 pairs of nerves that mostly serve the head and neckthe head and neck

Only the pair of vagus nerves extend Only the pair of vagus nerves extend to thoracic and abdominal cavitiesto thoracic and abdominal cavities

Most are mixed nerves, but three are Most are mixed nerves, but three are sensory onlysensory only

PNS: Cranial NervesPNS: Cranial Nerves

I Olfactory nerve—sensory for smellI Olfactory nerve—sensory for smell II Optic nerve—sensory for visionII Optic nerve—sensory for vision III Oculomotor nerve—motor fibers to III Oculomotor nerve—motor fibers to

eye muscleseye muscles IV Trochlear—motor fiber to eye IV Trochlear—motor fiber to eye

musclesmuscles

PNS: Cranial NervesPNS: Cranial Nerves

V Trigeminal nerve—sensory for the V Trigeminal nerve—sensory for the face; motor fibers to chewing musclesface; motor fibers to chewing muscles

VI Abducens nerve—motor fibers to VI Abducens nerve—motor fibers to eye muscleseye muscles

VII Facial nerve—sensory for taste; VII Facial nerve—sensory for taste; motor fibers to the facemotor fibers to the face

VIII Vestibulocochlear nerve—sensory VIII Vestibulocochlear nerve—sensory for balance and hearingfor balance and hearing

PNS: Cranial NervesPNS: Cranial Nerves

IX Glossopharyngeal nerve—sensory IX Glossopharyngeal nerve—sensory for taste; motor fibers to the pharynxfor taste; motor fibers to the pharynx

X Vagus nerves—sensory and motor X Vagus nerves—sensory and motor fibers for pharynx, larynx, and viscerafibers for pharynx, larynx, and viscera

XI Accessory nerve—motor fibers to XI Accessory nerve—motor fibers to neck and upper backneck and upper back

XII Hypoglossal nerve—motor fibers to XII Hypoglossal nerve—motor fibers to tonguetongue

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (1 of 4)

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (2 of 4)

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (3 of 4)

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (4 of 4)

PNS: Distribution of Cranial PNS: Distribution of Cranial NervesNerves

Figure 7.24

PNS: Classification of NervesPNS: Classification of Nerves

Mixed nervesMixed nerves• Both sensory and motor fibersBoth sensory and motor fibers

Sensory (afferent) nervesSensory (afferent) nerves• Carry impulses toward the CNSCarry impulses toward the CNS

Motor (efferent) nervesMotor (efferent) nerves• Carry impulses away from the CNSCarry impulses away from the CNS

PNS: Classification of NervesPNS: Classification of Nerves

Mixed nervesMixed nerves• Both sensory and motor fibersBoth sensory and motor fibers

Sensory (afferent) nervesSensory (afferent) nerves• Carry impulses toward the CNSCarry impulses toward the CNS

Motor (efferent) nervesMotor (efferent) nerves• Carry impulses away from the CNSCarry impulses away from the CNS

PNS: Cranial NervesPNS: Cranial Nerves

12 pairs of nerves that mostly serve 12 pairs of nerves that mostly serve the head and neckthe head and neck

Only the pair of vagus nerves extend Only the pair of vagus nerves extend to thoracic and abdominal cavitiesto thoracic and abdominal cavities

Most are mixed nerves, but three are Most are mixed nerves, but three are sensory onlysensory only

PNS: Cranial NervesPNS: Cranial Nerves

I Olfactory nerve—sensory for smellI Olfactory nerve—sensory for smell II Optic nerve—sensory for visionII Optic nerve—sensory for vision III Oculomotor nerve—motor fibers to III Oculomotor nerve—motor fibers to

eye muscleseye muscles IV Trochlear—motor fiber to eye IV Trochlear—motor fiber to eye

musclesmuscles

PNS: Cranial NervesPNS: Cranial Nerves

V Trigeminal nerve—sensory for the V Trigeminal nerve—sensory for the face; motor fibers to chewing musclesface; motor fibers to chewing muscles

VI Abducens nerve—motor fibers to VI Abducens nerve—motor fibers to eye muscleseye muscles

VII Facial nerve—sensory for taste; VII Facial nerve—sensory for taste; motor fibers to the facemotor fibers to the face

VIII Vestibulocochlear nerve—sensory VIII Vestibulocochlear nerve—sensory for balance and hearingfor balance and hearing

PNS: Cranial NervesPNS: Cranial Nerves

IX Glossopharyngeal nerve—sensory IX Glossopharyngeal nerve—sensory for taste; motor fibers to the pharynxfor taste; motor fibers to the pharynx

X Vagus nerves—sensory and motor X Vagus nerves—sensory and motor fibers for pharynx, larynx, and viscerafibers for pharynx, larynx, and viscera

XI Accessory nerve—motor fibers to XI Accessory nerve—motor fibers to neck and upper backneck and upper back

XII Hypoglossal nerve—motor fibers to XII Hypoglossal nerve—motor fibers to tonguetongue

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (1 of 4)

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (2 of 4)

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (3 of 4)

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (4 of 4)

PNS: Distribution of Cranial PNS: Distribution of Cranial NervesNerves

Figure 7.24

PNS: Cranial NervesPNS: Cranial Nerves

12 pairs of nerves that mostly serve 12 pairs of nerves that mostly serve the head and neckthe head and neck

Only the pair of vagus nerves extend Only the pair of vagus nerves extend to thoracic and abdominal cavitiesto thoracic and abdominal cavities

Most are mixed nerves, but three are Most are mixed nerves, but three are sensory onlysensory only

PNS: Cranial NervesPNS: Cranial Nerves

I Olfactory nerve—sensory for smellI Olfactory nerve—sensory for smell II Optic nerve—sensory for visionII Optic nerve—sensory for vision III Oculomotor nerve—motor fibers to III Oculomotor nerve—motor fibers to

eye muscleseye muscles IV Trochlear—motor fiber to eye IV Trochlear—motor fiber to eye

musclesmuscles

PNS: Cranial NervesPNS: Cranial Nerves

V Trigeminal nerve—sensory for the V Trigeminal nerve—sensory for the face; motor fibers to chewing musclesface; motor fibers to chewing muscles

VI Abducens nerve—motor fibers to VI Abducens nerve—motor fibers to eye muscleseye muscles

VII Facial nerve—sensory for taste; VII Facial nerve—sensory for taste; motor fibers to the facemotor fibers to the face

VIII Vestibulocochlear nerve—sensory VIII Vestibulocochlear nerve—sensory for balance and hearingfor balance and hearing

PNS: Cranial NervesPNS: Cranial Nerves

IX Glossopharyngeal nerve—sensory IX Glossopharyngeal nerve—sensory for taste; motor fibers to the pharynxfor taste; motor fibers to the pharynx

X Vagus nerves—sensory and motor X Vagus nerves—sensory and motor fibers for pharynx, larynx, and viscerafibers for pharynx, larynx, and viscera

XI Accessory nerve—motor fibers to XI Accessory nerve—motor fibers to neck and upper backneck and upper back

XII Hypoglossal nerve—motor fibers to XII Hypoglossal nerve—motor fibers to tonguetongue

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (1 of 4)

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (2 of 4)

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (3 of 4)

PNS: The Cranial NervesPNS: The Cranial Nerves

Table 7.1 (4 of 4)

PNS: Distribution of Cranial PNS: Distribution of Cranial NervesNerves

Figure 7.24