Central Nervous System and Peripheral Nervous System
Two subsets of the Peripheral Nervous System
Autonomic and Somatic Nervous Systems
Two Branches of the Autonomic Nervous System
Sympathetic and Parasympathetic
The Central Nervous System is made up by what?
The Brain and Spinal Cord
Function of Autonomic Nervous System
Automatic functions (ex respiration, digestion, cardiac)
Function of the Somatic Nervous System
Controls things under conscious control.
Function of Sympathetic
Gets ready for fight or flight.
Function of Parasympathetic
Rest and relaxation works in opposition to the sympathetic.
Neuron types in the parasympathetic
Acetylcholine, muscarine, nicotine
Neuron types in the ANS
Norepinephrine (noradrenaline) and Epinephrine (Adrenaline)
Characteristics of a Parasympathetic Ganglionic Synapse
1. Action Potential in Preganglionic neuron 2. Sodium moves in 3. Depolarization from Calcium influx. 4. Vesicles filled with Neurotransmitters (Ach) fuse with membrane 5. Release Ach to pass over to Postganglionic neuron 6. Binds to Nicotinic Receptor and Na+ moves into postganglionic (action potential) 7. Acetylcholineesterase is on postganglionic neuron.
Characteristics of Parasympathetic Organ Synpase (starting with Postganglionic)
1. Action potential moves from postganglionic neuron 2. Causes sodium influx leads to depolarization by Calcium influx 3. Ach vesicles fuse and release across synapse 4. Ach binds muscarinic receptor (gprotein) 5. Causes K efflux from the effector organ (also has acetylcholinesterase attached to organ membrane)
Summary of parasympathetic neurons and synapses: Preganglionic neurons
2)Synapse with postganglionic neurons at or near organ
3)Release ACH to activate nicotinic receptors on postganglionic neurons
Summary of parasympathetic neurons and synapses: Postganglionic neurons
2) Synapse on the target organ
3) Release ACH to activatemuscarinic receptorson the target organ
Characteristics of Sympathetic Ganglionic Synapse
1) Action potential causes sodium influx 2) Calcium influx leads to depolarization 3) vesicles of ACH fuse 4) ACH binds to Nicotinic receptor allowing Na+ influx continuing the action potential in postganglionic
Characteristics of sympathetic Organ Synapse
1) Action potential comes through postganglionic neuron 2) Leads to Na influx and Ca influx (depolarization) 3) Fusing of vesicle with NE. 4) NE binds to Adrenergic Receptor in Effector Organ (Gprotein) 5)NO Acetylcholinesterase
Summary of Sympathetic Neurons and Synapse: Preganglionic Neurons
2)Synapse with postganglionic neurons near spinal cord
3) Release ACH to activate nicotinic receptors on postganglionic neurons
Summary of sympathetic neurons and synapses: Postganglionic neurons
2) Synapse on Target Organ
3) Release Norepinpethrine to activate adrenergic receptors on target organs
Most ANS post ganglionic release what neurotransmitter?
How do organophosphatic drugs selectively affect the cholinergic system?
-At the Anionic site there is not a charge interaction ...strong electrophile
-Structure that makes selective for AChE is that it looks similar to Ach strong electrophile. NOthing really else bringing in. Looks like seletive but not. Beacuse AChE inmportant over body. Will see affects quickly. Many other do so but AChE so important-->Rapid pronounced effect.
-Nucleophile (Esteratic site) attacks electrophile and attaches (F leaves). Phosphorylation of serine.
-Does not hydrolyze off (faster to just to make new AChE)
-No very reversible (irreversible)
-Aging may happen.
What is aging?
-Partial hydrolysis so organophosphates strengthens bond.