Chapter 11 Peripheral Nervous System
Peripheral Nervous SystemOutline Introductory Comments 1. Autonomic Nervous System Parasympathetic versus sympathetic nervous systems 2. Somatic Nervous System 3. Adrenal Gland & Modified ANS 4. Chemical Anatagonists & Agonists 5. Neurotoxins
ANTAGONISTIC
Exception to the rule 1. Sweat gland and vascular smooth muscle only sympathetic innervation 2. Cooperativity between sympathetic and parasympathetic
Autonomic Nervous System Controls Found in Smooth Muscle Found in Glands Found in Cardiac muscle
sympathetic and parasympathetic neurons differ in several ways. Site of ganglion Length of pre and post-ganglionic fibers Type of neurotransmitters released pharmacologically
Divergence can occur model of the autonomic pathway “intrinsic neurons modulate”
Adrenal Medulla release primarily Epi. Parasympathetic Sympathetic Autonomic Nervous System Length of the fibers Spinal cord
Ach NE Adrenal Medulla release primarily Epi. Parasympathetic Sympathetic Autonomic Nervous System Neurotransmitters Ach Ganglion in circles Spinal cord TISSUE
Autonomic Division of Acetylcholine Receptor
Autonomic Division of Adrenergic Receptor
Cholinergic Antagonists Muscarinic Nicotinic Atropine, scopolamine Alpha-bungarotoxin (at muscle only, curare)
Adrenergic Antagonists Alpha Beta Alpha blockers Beta blockers: propranolol (B1 and B2) and metaprolol is B1 only
Ach Somatic Somatic Nervous System Neuromuscular Junction Always Excitatory!
Single neuron!
Let’s take a minute to look at the unique adrenal gland.
What other structure that we studied has two different embyronic origins?
Summary
Natural neurotoxins Funnel web spider, Agelenopsis aperta Blocks voltage gated Ca++ TTX blocks Na+ channels Bungarus multicinctus Blocks Acetylchoine receptors Fish hunting cone snail, Conus geographus Block Ca++ channels
Blocks exocytosis Botulism Toxin
Botox
Stimulant Binds to acetylcholine receptors Acetylcholine receptor
Summary: Effect of ANS on Various Physiological Systems
THE END