1. Anatomy of the Nervous System  Central nervous system (CNS)  Brain  Spinal cord  Peripheral nervous system (PNS)  Nerve outside the brain and spinal cord

3. The 12 pairs of cranial nerves

4. Spinal Nerves 31 pairs

5. Spinal Nerves

6. Dorsal ramus

8. Ventral ramus

10. The segmental innervation of anterior surface of trunk

11. PNS Throughout Life Embryonic muscles migrate to new locations Some skin dermatomes become displaced Muscles and skin always retain their original nerve supply

12. Spinal nerve plexus

13. The Cervical Plexus Deep in the neck under the sternocleidomastoid muscle. Formed by ventral rami of first 4 cervical nerves (C 1 – C 4 ) Most are cutaneous nerves Phrenic nerve – major nerve

14. The Cervical Plexus

15. (C5 -T1)

17. Brachial plexus main branches Axillary: shoulder (Deltoid) Musculocutaneous: Flexors in arm Radial: Extensors in arm and forearm Median: Flexors in forearm Ulnar: Flexors in forearm and hand

18. Lumbar Plexus

20. The Lumbar Plexus

21. Sacral Plexus

23. The Sacral Plexus c c c

24. Innervation of the Skin: Dermatomes Dermatome – an area of skin Innervated by cutaneous branches of a single spinal nerve Upper limb – skin is supplied by nerves of the brachial plexus Lower limb: Lumbar nerves – anterior surface Sacral nerves – posterior surface

25. Posterior Map of Dermatomes Anterior

26. Autonomic Nervous System General visceral motor part of the PNS Has 2 divisions (with opposite effects): - Parasympathetic: ‘housekeeping’ activities (rest and digest) - Sympathetic: extreme situations (fight or flight)

27. Sympathetic

31. Parasympathetic