The autonomic nervous system (ANS) regulates involuntary functions and is divided into the sympathetic and parasympathetic divisions. The sympathetic division, also called the thoracolumbar outflow, supplies smooth muscles, blood vessels, heart, lungs, glands, and gastrointestinal organs. It consists of preganglionic and postganglionic fibers and is arranged in three ganglia groups: paravertebral/sympathetic chain ganglia, prevertebral/collateral ganglia, and terminal/peripheral ganglia. The sympathetic chain ganglia are arranged segmentally along the vertebral column and are divided into cervical, thoracic, lumbar, and sacral ganglia. Preganglionic fibers originate in the

1. Saddam Ansari
2nd year
Tbilisi State Medical University
AUTONOMIC NERVOUS SYSTEM
(ANS)

2. Introduction
 Portion of nervous system
 Regulation of visceral functions
 Also known as vegetative or
involuntary nervous system

4. Sympathetic Division
 Called as thoracolumbar outflow
 Supplies smooth muscle fibers of
visceral organs
Blood vessels
Heart
Lungs
Glands
Gastrointestinal organs etc.

5. Continued…
 Consists of pre and post ganglionic fiber

6. Sympathetic Ganglia
Classified into 3 groups
1. Paravertebral or sympathetic
chain ganglia
2. Prevertebral or collateral ganglia
3. Terminal or peripheral ganglia

8. Sympathetic Chain Ganglia
Arrangement-
Segmental fashion
Location-
Anterolateral
surface of vertebral
column

9. Division of Sympathetic chain
Ganglia
1.Cervical ganglia-8cervial ganglia
into 3 groups
• Superior cervical ganglion
• Fusion of upper 4 cervical ganglia
• Middle cervical ganglion
• Fusion of 5th and 6th cervical ganglia
• Inferior cervical ganglion
• Fusion of 7th and 8th cervical ganglia

10. Continued…
2.Thoracic ganglia
12 thoracic ganglia present on
each side
Preganglionic fibers originates form
thoracic segment of spinal cord
Postganglionic fibers are
distributed into thorax and
abdomen

12. Continued…
3.Lumbar ganglia
• 5 lumbar ganglia
• Preganglionic fibers arises form L1 and
L2 segments and reach the lumbar
ganglia.
• Postganglionic fibers supply the
abdominal and pelvic organs:
• Urinary bladder
• Colon etc.

13. Continued…
4.Sacral ganglia
 5 sacral ganglia
 Receives preganglionic fibers from
L1 and L2 segments
 Postganglionic fibers innervates
blood vessels and sweat glands in
lower limb

14. Prevertebral or Collateral
Ganglia
Situated in thorax,abdomen and
pelvis
Preganglionic fibers arises from T5
to L2 segments
Prevertebral ganglia are :
Celiac ganglion
Superior mesenteric ganglion
Inferior mesenteric ganglion

16. Terminal or Peripheral Ganglia
 Situated within or close to structures
innervated by them.
 E.g. heart, bronchi, pancreas and
urinary bladder.

17. Sympathoadrenergic System
 Includes sympathetic division and
adrenal medulla
 Adrenal medulla is modified
sympathetic ganglion.
 Increase in sympathetic activity
increases the secretion of
catecholamines.