sympathetic chain anatomy for medical students and resident doctors and paramedics

1. RELEVANT ANATOMY
OF
THE SYMPATHETIC GANGLIA
BY
DR GEORGE OWUSU

2. OUTLINE
• INTRODUCTION
• EMBRYOLOGY OF THE SYMPATHETIC GANGLIA
• GROSS ANATOMY OF THE SYMPATHETIC GANGLIA
– SYMPATHETIC CHAIN
• STRUCTURE
• PARTS
– COLLATERAL (PRE-AORTIC) GANGLIA
• CONCLUSION

3. INTRODUCTION
• The sympathetic nervous system is part of the autonomic
nervous system, responsible for certain involuntary
control of the cardiac and smooth muscles and glands.
• Relay or synapse at certain points on their course
forming sympathetic ganglia.
• Connect with each other via nerve strands forming the
sympathetic trunk, collateral ganglia (pre-aortic ganglia)
and plexuses.
• In as much as the sympathetic network of cells serve vital
bodily functions, it is pertinent to understand that
derangement in some ganglionic cells could lead to
certain pathological anomalies such as Neuroblastoma

4. EMBRYOLOGY OF THE SYMPATHETIC
GANGLIA
• In the fifth week, neural crest
cells of the thoracic region
arising from the mantle layer
(which will go ahead to form
neuroblast), migrate on each
side of the spinal cord,
towards the region
immediately behind the dorsal
aorta.
• They form a bilateral chain of
sequentially arranged
sympathetic ganglia
interconnected by longitudinal
nerve fibers on each side of
the vertebral column .

5. EMBRYOLOGY OF THE SYMPATHETIC
GANGLIA
• From their position in the thorax,
neuroblast migrate towards the
cervical and lumbo-sacral regions,
extending the sympathetic chains
to their full length.
• Some neuroblast migrate in front
of the aorta to form the pre-
aortic ganglia
• Other sympathetic cells migrate
to organs such as the heart, lungs
and gastro-intestinal tract where
the give rise to sympathetic organ
plexuses

6. EMBRYOLOGY OF THE SYMPATHETIC
GANGLIA
• Initially the ganglia are
segmentally arranged, however
this arrangement is later
obscured by fusion of the ganglia
especially in the cervical region.
• Once the sympathetic chains
have been established, nerve
fibers originating in the viscero-
efferent column (intermediate
horn) of the thoracolumbar
segments of the penetrate the
ganglia of the chain.

7. GROSS ANATOMY
• SYMPATHETIC CHAIN:
• A pair of ganglionated
longitudinal cords of the
sympathetic nervous system
on both side of the
vertebral column
• EXTENT: It extends
bilaterally from the base of
the skull to the coccyx
where the converge with
each other forming the
ganglion impar

8. GROSS ANATOMY
• PARTS OF THE SYMPATHETIC CHAIN:
• The sympathetic chain is divided into four
parts:
• Cervical
• Thoracic
• Abdominal (lumbar)
• Pelvic (sacral)

9. GROSS ANATOMY
• CERVICAL PART:
• This extends from the base of
the skull to the first rib.
• Lies in the neck embedded in
the deep fascia between the
carotid sheath anteriorly and
longus coli and longus capitis
muscles posteriorly.
• Made up of three ganglia
(superior, middle and inferior
cervical ganglia)

10. GROSS ANATOMY
• THORACIC PART:
• The chain runs
downwards on the heads
of the ribs and leaves the
thorax on the side of the
body of the 12th thoracic
vertebra behind the
medial arcuate ligament.
• It is made up of eleven
segmentally arranged
ganglia (following
formation of the stellate
ganglion)

11. GROSS ANATOMY
• ABDOMINAL (LUMBAR)
PART :
• The sympathetic trunk
enters the abdomen by
passing behind the medial
arcuate ligament, on the
psoas major.
• Runs along the medial
margin of the psoas
muscle to the pelvic brim.
• The lumbar part of the
sympathetic trunk contains
about four ganglia.

12. GROSS ANATOMY
• ABDOMINAL (LUMBAR) PART:
• Branches:
• Gray rami communicans to all
lumbar spinal nerves.
• Lumbar splanchnic nerves
(pre-ganglionic) arising from
all ganglia
– Those from the 1st and 2nd
ganglia supply the pre-aortic
ganglia
– The 3rd and 4th splanchnic
nerves form the superior
hypogastric plexus in front of
the L5 vetebra and sacral
promontory
– The superior hypogastric plexus
sends fibers (hypogastric nerve)
to join the pelvic inferior
hypogastric plexus.

13. GROSS ANATOMY
• PELVIC (SACRAL) PART :
• The sympathetic chain enters
the pelvis crossing the pelvic
brim behind the common
iliac vessels
• Extends down the concavity
of the sacrum on the medial
margins of the anterior sacral
foramina to converge in front
of the coccyx; uniting to form
the ganglion impar.
• branches:
– Somatic branches to all sacral
nerves
– Pelvic visceral branches which join
the inferior hypogastric plexus

14. GROSS ANATOMY
• COLLATERAL (PRE-
AORTIC) GANGLIA:
• This comprises of clusters
of ganglia and plexuses in
front of the aorta, formed
around its branches.
• The major ganglia include
the:
• Coeliac
• Superior mesenteric
• Aorticorenal
• Inferior mesenteric

15. GROSS ANATOMY
• COLLATERAL (PRE-AORTIC) GANGLIA:
• The supply the gut and abdominal viscera via
plexuses which accompany their blood supply.
• The greater and lesser splanchnic nerves
pierce the crura of the diaphragm and enter
the large coeliac ganglia which lie in front of
the crura and superior mesenteric ganglia
which connects with other ganglia via the
inter mesenteric plexuses

16. GROSS ANATOMY
• COLLATERAL (PRE-AORTIC) GANGLIA:
• Coeliac ganglia: supplies the liver, gall bladder,
pancreas, gonads and foregut (pre-ganglionic
fiber from the greater splanchnic nerve continues
to supply the medulla of the adrenal gland).
• Superior mesenteric ganglion: supplies the mid
gut
• Aorticorenal ganglia: supplies the kidneys
• Inferior mesenteric ganglia: supplies the hindgut.

17. CONCLUSION
• The sympathetic nervous system is enabled to
carry out its vital activities through a well
articulated network of nerves, ganglia and
plexuses reaching every part of the body.
• However a good knowledge and
understanding of the embryological origin and
structure of the sympathetic ganglion is key in
our understanding of certain pathological
anomalies such as Neuroblastoma and other
neurocristopathies.

18. THANK YOU!!!!

19. REFERENCES
• Chummy sinnatamby. Last’s anatomy 12th
edition 2011. 278:280
• Keith Moore et al. clinically oriented anatomy
6th edition 2010. 318:319
• Frank Netter. Atlas of human anatomy 6th
edition 2014
• Sadler T. W. et al. langmans medical
embryology 9th edition 474:477