Sympathetic nervous system

Sympathetic Nervous system and Sympathetic chain

1. Sympathetic vs parasympatheticDr Rajiv Ranjan

2. Role
•Homeostasis
•Provides neural control of smooth muscle,
cardiac muscle&glandular secretory cellsDr Rajiv Ranjan

3. Dr Rajiv Ranjan

4. Dr Rajiv Ranjan

5. gangliaDr Rajiv Ranjan

6. Vasomotor supply
Vasoconstrictor
Sudomotor
PilomotorDr Rajiv Ranjan

7. Sympathetic NS
•Visceral afferent –unipolar neurons; soma located in either
cranial sensory or dorsal root ganglia
•Visceral efferent –2 neurons bet
n
CNS & Organ
preganglionicand postganglionicneurons
•Cell body of preganglionic neurons are located in the lateral
grey columns of the spinal cord
•Their axons pass to peripheral ganglia; synapse with
postganglionic neurons
•The postganglionic neurons(30:1) are more in number & their
axons are usuallyunmyelinated
•Sympathetic trunk ganglia –C-8, T-11, L-4, S-4Dr Rajiv Ranjan

8. Rami communicantes
White rami communicanspreganglionic fibres
Grey ,, ,, postganglionic fibre
All Thoracic & L2 have both
Others have only grey rami communicantesDr Rajiv Ranjan

9. Preganglionic fibres4 fate
Synapse with soma of corresponding Sympathetic trunk ganglion
Synapse with soma of other Sympathetic trunk ganglion Up or Down
Leave the trunk without synapsing & pass to ganglion in autonomic plexus (collateral br)
Leave the trunk without synapsing to pass to adrenal medullaDr Rajiv Ranjan

10. Dr Rajiv Ranjan

11. Postganglionic fibresjoin spinal nerve by grey rami communicants
Supplied through ventral & dorsal branches to the segmentDr Rajiv Ranjan

12. Splanchnic/visceral nerveDr Rajiv Ranjan

13. cardiac plexus
Cervical ganglia + T1-4Dr Rajiv Ranjan

14. Splanchnic/visceral nerve
Greater splanchnic N (T5-9)
Lesser splanchnic N (T10-11)
Least splanchnic N (T12)Dr Rajiv Ranjan

15. Dr Rajiv Ranjan

16. THORACIC SYMPATHETIC TRUNKDr Rajiv Ranjan

17. THORACIC SYMPATHETIC TRUNK
•Lie post. to costovertebralpleura
•Contains 11 pairs of ganglion lie ant to head of ribs
•Caudally thoracic sympathetic trunk passes dorsal to medial
arcuateligament to become lumbar sympathetic trunk
•1
st
thoracic ganglion is often fused with inf. Cervical ganglion
forming stellate ganglion
•Each ganglion receives a preganglionic white ramus from the
ventral ramus of its nerve
•After relay in the ganglion a postganglionic grey ramus returns to
each thoracic nerve
•Postganglionic sympathetic fibressupply cardiac, pulmonary
plexus, trachea, oesophagus, thoracic aortaDr Rajiv Ranjan

18. Dr Rajiv Ranjan

19. Splanchnic nerves
Greater Splanchnic nerve –formed by branches of
5
th
to 9
th
ganglia
Lesser Splanchnic nerve –from 10
th
& 11
th
ganglia
Least Splanchnic nerve –from 12
th
gangliaDr Rajiv Ranjan

20. CERVICAL GANGLIADr Rajiv Ranjan

21. Dr Rajiv Ranjan

22. APPLIED
Horner's Syndrome
Endoscopic thoracic sympathectomyDr Rajiv Ranjan

23. Causalgia
(complex regional pain syndrome type II)
•Result of partial injury to a peripheral nerve
•Sympathetic postganglionic neurons coursing
in the injured nerve develop abnormal
connections to nociceptive dorsal root
ganglion neurons
•S/S –spontaneous burning pain,
hypersensitivity of the skin, pain triggered by
loud noises or strong emotions, sweating and
reduced temperature of the limb, mottling of
the skin, and swelling of the extremityDr Rajiv Ranjan