1. Chapter 6 The Nervous System-Peripheral NS
Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 6 The Nervous System-Peripheral NS
Lecture Slides in PowerPoint by Jerry L. Cook
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

2. PERIPHERAL NERVOUS SYSTEM
Nerve = bundle of neuron fibers outside the CNS
Ganglion = bundle of neuron cell bodies outside the CNS

3. Structure of a Nerve Figure 7.20
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.20

4. Classification of Nerves
AFFERENT (SENSORY) NERVES – carry impulses toward the CNS
EFFERENT (MOTOR) NERVES – carry impulses away from the CNS
MIXED NERVES – both sensory and motor fibers

5. CRANIAL NERVES 12 pairs of nerves that arise from the brain
Mostly serve the head and neck
Numbered in order, from front to back
Most are mixed nerves, but three are sensory only

6. Distribution of Cranial Nerves
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.21

8. Cranial Nerves I OLFACTORY (S) nerve – sense of smell
II OPTIC (S) nerve – sense of vision

9. Cranial Nerves III OCULOMOTOR nerve
motor fibers to 4 (of 6) eye muscles
Dilates/constricts the iris and lens
IV TROCHLEAR nerve – motor fiber to one eye muscle

10. Cranial Nerves V TRIGEMINAL nerve
sensory for the face, mucosa of nose and mouth
motor fibers to jaw muscles
VI ABDUCENS nerve – motor fiber to one eye muscle

11. Cranial Nerves VII FACIAL nerve sense of taste for anterior tongue
motor fibers to the face, lacrimal (tears) glands, and salivary glands
VIII VESTIBULOCOCHLEAR (S) nerve – sensory for balance and hearing

12. Cranial Nerves IX GLOSSOPHARYNGEAL nerve
sense of taste for posterior tongue
motor fibers to the pharynx (swallowing)
X VAGUS nerve – sensory and motor fibers for pharynx, larynx, thoracic and abdominal viscera
gloss- , glosso – prefix for tongue

13. Cranial Nerves
XI ACCESSORY (M) nerve – motor fibers to neck/upper back
XII HYPOGLOSSAL nerve – motor fibers to tongue

14. SPINAL NERVES 31 pairs at the level of each vertebra: 8 cervical
12 thoracic
5 lumbar
5 sacral
1 (coccygeal nerve) at very end

15. Spinal Nerves Cervical nerves Thoracic nerves Lumbar nerves
Sacral nerves
LATERAL VIEW
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.22a

16. SPINAL NERVES
Spinal nerve fibers converge into bundles called plexuses
Fibers are criss-crossed and then branch-out from the plexus
Numbered in order from top to bottom

17. Spinal Nerves Cervical plexus (C1-C5) Cervical nerves Thoracic nerves
Intercostal nerves no plexus (T1-T12)
Lumbar nerves
Sacral nerves
Lumbar plexus (L1-L4)
Sacral plexus (L4 – L5; S1-S4)
LATERAL VIEW
FRONTAL VIEW
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.22a

18. Distribution of Cervical Plexus and Brachial Plexus
Phrenic nerve (C3-C5)
Nerve
Distribution of Cervical Plexus and Brachial Plexus
Brachial plexus (C5-C8; T1)
Axillary
Nerve
Musculo-cutaneous
Nerve
Median
Nerve
Radial
Nerve
Ulnar
Nerve
Radius
NECK, SHOULDER, ARM
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

19. Distribution of Lumbar Plexus
Nerve
Distribution of Lumbar Plexus
ANTERIOR LEG
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

20. Distribution of Sacral Plexus
Nerve
Distribution of Sacral Plexus
Gluteal
Sciatic
Posterior femoral cutaneous
POSTERIOR LEG
Figure 7.23
Posterior Leg
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

21. Anatomy of Spinal Nerves
Dorsal ramus – serves the skin and muscles of the posterior trunk
Ventral ramus – forms a complex of networks (plexus) for the anterior
Add to your notes. Dgm in txt. Bk pg. 219
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 7.22b