Sympathetic division (Thoracolumbar)

Question 1

Sympathetic division

Answer 1

• chemical neurotransmitter= norepinephrine
• fibers are termed “adrenergic”

-Sympathetic:
   preganglionic neuron(CNS)--->postganglionic neuron(PNS)--->norepinephrine

-Parasympathetic:
   preganglionic neuron(CNS)-------------->postganglionic neuron(PNS)--->Acetylcholine

Question 2

why is the sympathetic division generally excitatory? what are its characteristics?

Answer 2

• preparation for emergency or physical stress

- increases HR/BP, dilates pupils, reduces digestive activity, raises respiratory rate and volume.

Question 3

Paravertebral Ganglia:

Answer 3

• 12 pair thoracic/ 3 pair lumbar
  A). white rami:
  -contain short, myelinated, preganglionic fibers

B). gray rami:
-contain long, unmyelinated, postganglionic fibers that merge with spinal somatic nerves

C). Splanchnics:

• myelinated, preganglionic fibers passing through paravertebral ganglia to innervate abdominal organs.
• form three peripheral (collateral) ganglia in the abdominal cavity.