Autonomic Nervous System

Autonomic Nervous System

1. Sympathetic

   • Preganlionic
     • Come from thoracolumbar
     • Synapse in the paravertebral ganglia
     • Could also form splanic nerves which synapse in collateral ganglia
     • Innervates Adrenal Medulla
       • Secretes epinephrine and norepinephrine when stimulated
   • Postganglionic
     • norepinephrine

2. Parasympathetic

   • Preganglioic
     • From Craniosacral region
     • Synapse on ganglia located on or near effector
     • Do not travel with somatic
     • Acetylcholine
   • Postganglionic
     • Very short to the effectors
     • Acetylcholine release= rest and digest
   • Cranial Nerves
     • Occulomotor
       • Pre: midbrain and synapse on ciliary ganglion
       • Post: innervate ciliary muscles of eye
     • Vagus
       • Pre: exit medulla; branch and travel to effector organs

3. Neurons release mainly acetylcholine and norepinephrine

4. Adrenergic receptors

   • Alpha
     • a(1)
     • a(2)
       • presynaptic axons; result in inhibition of norepinephrine release in synapse
     • Norepinephrine
   • Beta
     • b(1)
     • b(2)
     • Blood epinephrine

5. Cholinergic

   • Nicotinic
     • autonomic ganglia
     • Ach from pre
   • Muscarinic
     • Visceral organs
     • Ach from post