1. The Nervous System

2. PNS: Spinal Nerves
There is a pair of spinal nerves at the level of each vertebrae
Formed by the combination of the
Named for the region from which they arise

3. PNS: Spinal Nerves
Figure 7.25a

4. PNS: Anatomy of Spinal Nerves
Spinal nerves divide soon after leaving the spinal cord
Dorsal rami—
Ventral rami

5. PNS: The Spinal Nerves
Figure 7.25b

6. PNS: Spinal Nerve Plexuses
Table 7.2 (1 of 2)

7. PNS: Spinal Nerve Plexuses
Table 7.2 (2 of 2)

8. PNS: Distribution of Major Peripheral Nerves of the Upper and Lower Limbs
Figure 7.26a

9. PNS: Distribution of Major Peripheral Nerves of the Upper and Lower Limbs
Figure 7.26b

10. PNS: Distribution of Major Peripheral Nerves of the Upper and Lower Limbs
Figure 7.26c

11. PNS: Autonomic Nervous System
Motor subdivision of the PNS
Also known as the involuntary nervous system
Two subdivisions

12. PNS: Differences Between Somatic and Autonomic Nervous Systems
Nerves
Somatic:
Autonomic:
Effector organs

13. PNS: Differences Between Somatic and Autonomic Nervous Systems
Neurotransmitters
Somatic:
Autonomic:

14. PNS: Comparison of Somatic and Autonomic Nervous Systems
Figure 7.27

15. PNS: Anatomy of the Sympathetic Division
Originates from T1 through L2
Ganglia are at the sympathetic trunk (near the spinal cord)
Short pre-ganglionic neuron and long post-ganglionic neuron transmit impulse from CNS to the effector

16. PNS: Anatomy of the Autonomic Nervous System
Figure 7.28

17. PNS: Sympathetic Pathways
Figure 7.29

18. PNS: Anatomy of the Parasympathetic Division
Originates from the brain stem and S1 through S4
Terminal ganglia are at the effector organs
Always uses acetylcholine as a neurotransmitter

19. PNS: Autonomic Functioning
Sympathetic—
Response to unusual stimulus
Takes over to increase activities
Remember as the “E” division

20. PNS: Autonomic Functioning
Parasympathetic
Conserves energy
Maintains daily necessary body functions
Remember as the “D” division

21. Effects of the Sympathetic and Parasympathetic Divisions of the ANS
Table 7.3 (1 of 2)

22. Effects of the Sympathetic and Parasympathetic Divisions of the ANS
Table 7.3 (2 of 2)

23. Development Aspects of the Nervous System
The nervous system is formed during the first month of embryonic development
Any maternal infection can have extremely harmful effects

24. Development Aspects of the Nervous System
No more neurons are formed after birth, but growth and maturation continues for several years