topic 20: symphatetic trunk

Question 1

Intro

Answer 1

-ganglionated chain situated on each side of vertebral colum
-superiorly its continuous with thoracic symphatetic trunk & thoracic inlet
-inferiorly aftr pass behind medial cruciate ligament it is continuous with lumbar symphatetic chain
-made of 12 ganglia corresponding to the 12 thoracic spinal nerve ; first ganglia fuses with inferior cervical symphatetic trunk to form stellate/cervicothoracic ganglia

• so there are 11 ganglia in the thoracic symphatetic trunk, each lying @ level of corresponding intervertebral discs & connected to corresponding spinal nerves by white & grey rami communicants

2 main branches : media & lateral

Question 2

about medial branches

Answer 2

-supply viscera
-from 1st o 5th ganglia they consist of postganglionic fibers: distributed to heart,great vessels & esophagus through plexuses ; cardiac,pulmonary, aortic & esophageal plexus

from 5th-12th ganglia consist of pre-ganglionic fibers that form 3 main nerves:

1.greater splanchnic nerve: -fibers from 5-9th ganglias
-descends, pierces crus, terminates mainly into celiac ganglia (partially into aortical renal ganglia & suprarenal gland)
2.lesser: from 10-11th ganglia
-same course
-terminates in aorticorenal ganglia

3.lesser: 12 ganglia
-same course
-terminates in renal plexus

Question 2

about lateral branch

Answer 2

-supply limb & body wall (supply is pilomotor,sudomotor&vasomotor for skin areas)
-preganglionic fibers arise from ventral horns of spinal segments
-enter symphatetic ganglion via white rami communicants
-fibers re-eter spinal nerve via grey rami communicants & supply corrsponding dermatomes of upper limb & body wall